ASE B-Series Academy · B2 Painting and Refinishing

ASE B2 - A. Surface Preparation

15 exam questions · 27% of the ASE B2 test (the heaviest area)

Lesson Overview

[IMAGE PLACEHOLDER] Hero image: a tech sanding and masking a panel in the booth, prepped surfaces ready for primer.
📷 Save image as: ase_b2a_hero1.jpg  ·  prompt for labs.google.comCreate an image for an automotive refinishing training lesson. Subject: Hero image: a tech sanding and masking a panel in the booth, prepped surfaces ready for primer. The technician must be shown wearing correct PPE for this task: a particulate respirator, safety glasses, gloves, steel-toe shoes, and a shop uniform. Style: photorealistic high-resolution photograph, automotive body shop / paint booth setting, professional lighting, shallow depth of field, sharp detail, true-to-life color, no text, no watermark. Aspect ratio 16:9.

Surface preparation is where a paint job is won or lost. The color and clear get the attention, but almost every refinish defect, peeling, mapping, bleed-through, poor hiding, traces back to how the surface was cleaned, sanded, treated, and masked first. Prep is the work nobody sees and everybody judges.

This is the biggest part of the ASE B2 test, about 15 questions. Master it and you protect every job that follows. The plan is simple: read the surface, clean it, get it flat and sound, treat and prime it, then protect everything you are not painting.

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Table of Contents

[VISUAL PLACEHOLDER] Roadmap graphic: Inspect & Clean → Strip/Sand/Featheredge → Treat/Prime/Fill → Mask/Protect → Recap.
📷 Save image as: ase_b2a_toc1.jpg  ·  prompt for labs.google.comCreate an image for an automotive refinishing training lesson. Subject: Roadmap graphic: Inspect & Clean → Strip/Sand/Featheredge → Treat/Prime/Fill → Mask/Protect → Recap. Style: clean modern vector infographic illustration, flat design, clearly labeled, high-contrast, white background, instructional, no watermark. Aspect ratio 16:9.
What you'll learn here. Surface Preparation is the heaviest area on the ASE B2 test. Listed below is every ASE Surface Preparation task (the subcategories) this lesson teaches, grouped by module. Each one is also tagged inside its lesson card with the official ASE task and what it means in plain shop terms. Click any task to jump straight to it.
iWhat you need to knowThe basics behind good prep↓ 1Module 1 — Inspect, Plan & CleanRead the surface, remove contamination and corrosion, control static↓ A1Inspect the surface & make a plan↓ A2Remove dirt, wax, grease & contaminants↓ A3Identify & remove surface corrosion↓ A4Final cleaning, dust removal & tack↓ A5Control static electricity↓ #Numbers & Specs for this module↓ 🔧Practice in the Lab↓ 2Module 2 — Strip, Sand & FeatheredgeRemove finish, sand, featheredge, block sand↓ A6Remove the paint finish↓ A7Sand areas to be refinished↓ A8Featheredge the repair↓ A9Block sand primer & filler↓ #Numbers & Specs for this module↓ 🔧Practice in the Lab↓ 3Module 3 — Treat, Prime & FillSubstrate treatment, primer-surfacer, glaze, sealer, pinholes↓ A10Identify the substrate & apply the right treatment↓ A11Mix & apply primer-surfacer↓ A12Apply finishing filler (glaze)↓ A13Apply primer-sealer & adhesion promoter↓ A14Identify & correct pinholes↓ #Numbers & Specs for this module↓ 🔧Practice in the Lab↓ 4Module 4 — Mask, Protect & CoatingsMasking, blend prep, stone-chip & corrosion coatings, trim↓ A15Mask & protect areas not refinished↓ A16Prepare adjacent areas for blending↓ A17Apply stone-chip resistant coating↓ A18Restore corrosion protection↓ A19Trim, moldings, decals & pinstripes↓ #Numbers & Specs for this module↓ 🔧Practice in the Lab↓ 🖨Printable Cheat SheetOne-page summary you can print↓ ★Category RecapQuick review↓ A–ZGlossaryEvery key term in this category↓ 🎯Practice & AssessmentPre/post test, key terms, tool ID, skills sheet & evaluation↓ ✓Test YourselfGo to the simulator↓
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What you need to know (applies to all four modules)

[VISUAL PLACEHOLDER] Cutaway of the paint layers: metal, e-coat, primer, basecoat, clearcoat, with the prep steps labeled.
📷 Save image as: ase_b2a_layers1.jpg  ·  prompt for labs.google.comCreate an image for an automotive refinishing training lesson. Subject: Cutaway of the paint layers: metal, e-coat, primer, basecoat, clearcoat, with the prep steps labeled. Style: clean modern vector infographic illustration, flat design, clearly labeled, high-contrast, white background, instructional, no watermark. Aspect ratio 16:9.

Paint sticks two ways and needs both: a mechanical bond (sanding/scuffing makes tiny teeth for the paint to grip) and a chemical bond (a clean, compatible surface). Every prep step is building one or both of those.

Know your substrate (steel, galvanized, aluminum, plastic, composite, old paint), because the treatment changes. Bare metals need a self-etching primer or conversion coating; plastics need an adhesion promoter; old finishes need cleaning, scuffing, and often a sealer.

Grit goes coarse to fine. You sand with coarser paper to cut and shape, then step up through finer grits so the last scratch is small enough to be hidden by the next coat. Skipping grits leaves scratches that telegraph through the paint.

Clean, then sand, then clean again. Wax and grease remover comes before sanding (so you do not grind contamination in) and the surface is cleaned and tacked again right before coating.

Module 1 of 4

Inspect, Plan & Clean the Surface

[VISUAL PLACEHOLDER] Module 1 banner: tech inspecting a panel with a mil gauge and wiping it with wax and grease remover.
📷 Save image as: ase_b2a_m1_banner1.jpg  ·  prompt for labs.google.comCreate an image for an automotive refinishing training lesson. Subject: Module 1 banner: tech inspecting a panel with a mil gauge and wiping it with wax and grease remover. The technician must be shown wearing correct PPE for this task: chemical-resistant gloves, splash goggles, a respirator, steel-toe shoes, and a shop uniform. Style: clean modern vector infographic illustration, flat design, clearly labeled, high-contrast, white background, instructional, no watermark. Aspect ratio 16:9.

INSPECT, PLAN & CLEAN THE SURFACE (The 30-second Lesson Overview)

Inspect & planIdentify the substrate, finish type, and film thickness (mil gauge), then plan the repair. Over ~12 mils, strip it.
Remove contaminantsWash, then wax and grease remover, before any sanding. Skipping this causes fish-eyes and poor adhesion.
Remove corrosionTake rust down to clean, bright metal, then treat and prime right away.
Final clean & tackBlow off, final wash, and tack just before coating. A clean panel is a clean job.
Control staticStatic pulls dust to the panel, especially plastic. Ground the vehicle and use anti-static methods, not a dry rag.
Goal: read a surface, clean it correctly in the right order, deal with corrosion, and stop static from pulling dust into your finish.
💡 Did you know? The entire factory paint job on a car (e-coat, primer, base, and clear) is usually only about 4 to 6 mils thick, roughly a sheet of notebook paper. That is why you measure with a mil gauge before you sand: there is not much paint to work with.
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Safety first

The skills

[VISUAL PLACEHOLDER] Mil gauge reading film thickness on a panel; chart of substrate types.
📷 Save image as: ase_b2a_surface_plan1.jpg  ·  prompt for labs.google.comCreate an image for an automotive refinishing training lesson. Subject: Mil gauge reading film thickness on a panel; chart of substrate types. Style: clean modern vector infographic illustration, flat design, clearly labeled, high-contrast, white background, instructional, no watermark. Aspect ratio 16:9.

Inspect the surface & make a plan

ASE Surface Prep Task · A1"Inspect, identify, and document the substrate, type of finish, surface condition, and film thickness; develop a plan for refinishing."What it means: read the panel and decide how far you have to go, before you ever pick up a tool.

Before you touch a sander, you decide what you are working with and how far you have to go.

Key pointsIdentify the substrate, the type of finish, and the surface condition. Measure existing film build with a mil gauge; total build over about 12 mils usually has to be stripped.
How to Do It (Step by Step)
  1. Wash the vehicle with soap (a no-wax car wash soap) and water using a clean wash mitt. Dry it, then look it over under good light for the substrate type (steel, galvanized steel, aluminum, plastic, or composite) and the type and condition of the finish.
  2. Read film thickness on the body panels with an electronic mil gauge, taking readings in several spots, not just one.
    1. Decide repair vs. strip:
      • Under ~12 mils — usually safe to prep and recoat
      • Over ~12 mils — strip to a sound layer, then recoat
  3. Write the repair plan — the products, materials, and order of operations. For example:
    • Products: wax & grease remover, self-etching primer (for bare metal), 2K primer-surfacer, primer-sealer, basecoat and clearcoat
    • Materials: sandpaper stepped P180 → P320 → P400, body filler and glaze, masking paper and tape, tack cloth
    • Order of operations: clean → strip/sand → treat bare metal → primer-surfacer → block sand → seal → mask → refinish
🎬 Video demo + narration
Film this procedure (or build a narrated slideshow from the step images). Save as ase_b2a_inspect_demo.mp4 in this category's images folder, then swap this box for a <video> player.
Narration script (read in order):
  1. Wash the vehicle with soap (a no-wax car wash soap) and water using a clean wash mitt . Dry it, then look it over under good light for the substrate type (steel, galvanized steel, aluminum, plastic, or composite) and the type and condition of the finish .
  2. Read film thickness on the body panels with an electronic mil gauge , taking readings in several spots , not just one.
  3. Write the repair plan — the products, materials, and order of operations. For example:
📷 Step-by-step image prompts — consistent series (generate in one session; reuse the same subject/style reference so every step matches)
Step 1 — save as ase_b2a_inspect_s11.jpg: Create an image showing this exact step in an automotive refinishing lesson: Wash the vehicle with soap (a no-wax car wash soap) and water using a clean wash mitt . Dry it, then look it over under good light for the substrate type (steel, galvanized steel, aluminum, plastic, or composite) and the type and condition of the finish . CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 2 — save as ase_b2a_inspect_s21.jpg: Create an image showing this exact step in an automotive refinishing lesson: Read film thickness on the body panels with an electronic mil gauge , taking readings in several spots , not just one. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 3 — save as ase_b2a_inspect_s31.jpg: Create an image showing this exact step in an automotive refinishing lesson: Write the repair plan — the products, materials, and order of operations. For example: CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.

Remember: Measure first. The mil gauge tells you whether you can build on the old paint or must strip it.

[VISUAL PLACEHOLDER] Wiping a panel with wax and grease remover, two-rag method.
📷 Save image as: ase_b2a_dirt_wax_grease1.jpg  ·  prompt for labs.google.comCreate an image for an automotive refinishing training lesson. Subject: Wiping a panel with wax and grease remover, two-rag method. Style: photorealistic high-resolution photograph, automotive body shop / paint booth setting, professional lighting, shallow depth of field, sharp detail, true-to-life color, no text, no watermark. Aspect ratio 16:9.

Remove dirt, wax, grease & contaminants

ASE Surface Prep Task · A2"Soap and water wash the entire area to be repaired; remove dirt, grease, wax, silicone, and other contaminants."What it means: get all contamination off before you sand, so it cannot get ground in and ruin adhesion.
Key pointsClean before you sand. Wax, grease, silicone, and road grime sanded into the surface cause fish-eyes and adhesion failure later.
How to Do It (Step by Step)
  1. Wash with soap and water to remove the heavy dirt and grime.
  2. Wipe with wax and grease remover using the two-rag method: one rag to apply, a clean dry rag to wipe before it flashes off.
  3. Work small areas so the remover does not dry on the surface.
  4. Clean adjacent panels too, so you do not drag contamination into the repair.
🎬 Video demo + narration
Film this procedure (or build a narrated slideshow from the step images). Save as ase_b2a_clean_demo.mp4 in this category's images folder, then swap this box for a <video> player.
Narration script (read in order):
  1. Wash with soap and water to remove the heavy dirt and grime.
  2. Wipe with wax and grease remover using the two-rag method: one rag to apply, a clean dry rag to wipe before it flashes off.
  3. Work small areas so the remover does not dry on the surface.
  4. Clean adjacent panels too, so you do not drag contamination into the repair.
📷 Step-by-step image prompts — consistent series (generate in one session; reuse the same subject/style reference so every step matches)
Step 1 — save as ase_b2a_clean_s11.jpg: Create an image showing this exact step in an automotive refinishing lesson: Wash with soap and water to remove the heavy dirt and grime. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 2 — save as ase_b2a_clean_s21.jpg: Create an image showing this exact step in an automotive refinishing lesson: Wipe with wax and grease remover using the two-rag method: one rag to apply, a clean dry rag to wipe before it flashes off. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 3 — save as ase_b2a_clean_s31.jpg: Create an image showing this exact step in an automotive refinishing lesson: Work small areas so the remover does not dry on the surface. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 4 — save as ase_b2a_clean_s41.jpg: Create an image showing this exact step in an automotive refinishing lesson: Clean adjacent panels too, so you do not drag contamination into the repair. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.

Remember: Clean, then sand, then clean again. Wax and grease remover comes before the paper.

[VISUAL PLACEHOLDER] Surface rust being taken down to bright metal, then treated.
📷 Save image as: ase_b2a_surface_corrosion1.jpg  ·  prompt for labs.google.comCreate an image for an automotive refinishing training lesson. Subject: Surface rust being taken down to bright metal, then treated. Style: photorealistic high-resolution photograph, automotive body shop / paint booth setting, professional lighting, shallow depth of field, sharp detail, true-to-life color, no text, no watermark. Aspect ratio 16:9.

Identify & remove surface corrosion

ASE Surface Prep Task · A3"Inspect for, identify, and remove corrosion from the surface to be refinished."What it means: take rust down to sound, bright metal and treat it before it spreads back under the paint.
Key pointsRust must come off down to clean, bright metal, and bare metal must be treated and primed quickly before it flash-rusts again.
How to Do It (Step by Step)
  1. Remove the corrosion mechanically (sanding/abrasive) or chemically down to bright metal.
  2. Clean the bare metal.
  3. Apply a metal treatment/conversion coating or self-etching primer to stop new corrosion.
  4. Prime promptly so the bare metal does not flash-rust.
🎬 Video demo + narration
Film this procedure (or build a narrated slideshow from the step images). Save as ase_b2a_corrosion_demo.mp4 in this category's images folder, then swap this box for a <video> player.
Narration script (read in order):
  1. Remove the corrosion mechanically (sanding/abrasive) or chemically down to bright metal.
  2. Clean the bare metal.
  3. Apply a metal treatment/conversion coating or self-etching primer to stop new corrosion.
  4. Prime promptly so the bare metal does not flash-rust.
📷 Step-by-step image prompts — consistent series (generate in one session; reuse the same subject/style reference so every step matches)
Step 1 — save as ase_b2a_corrosion_s11.jpg: Create an image showing this exact step in an automotive refinishing lesson: Remove the corrosion mechanically (sanding/abrasive) or chemically down to bright metal. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 2 — save as ase_b2a_corrosion_s21.jpg: Create an image showing this exact step in an automotive refinishing lesson: Clean the bare metal. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 3 — save as ase_b2a_corrosion_s31.jpg: Create an image showing this exact step in an automotive refinishing lesson: Apply a metal treatment/conversion coating or self-etching primer to stop new corrosion. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 4 — save as ase_b2a_corrosion_s41.jpg: Create an image showing this exact step in an automotive refinishing lesson: Prime promptly so the bare metal does not flash-rust. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.

Remember: Bare metal rusts fast. Treat and prime the same day you expose it.

[VISUAL PLACEHOLDER] Blowing off and tacking a panel just before priming.
📷 Save image as: ase_b2a_cleaning_dust_removal1.jpg  ·  prompt for labs.google.comCreate an image for an automotive refinishing training lesson. Subject: Blowing off and tacking a panel just before priming. Style: photorealistic high-resolution photograph, automotive body shop / paint booth setting, professional lighting, shallow depth of field, sharp detail, true-to-life color, no text, no watermark. Aspect ratio 16:9.

Final cleaning, dust removal & tack

ASE Surface Prep Task · A4"Remove dust and clean the surface with a final cleaning solution; remove remaining dust or lint with a tack rag before coating."What it means: the last clean right before paint, so nothing lands in the finish.
Key pointsRight before coating, the panel gets a final clean, a blow-off, and a tack cloth wipe to remove dust and lint.
How to Do It (Step by Step)
  1. Blow the panel and seams off with clean, dry air.
  2. Final-wipe with the correct cleaner for the coating you are about to spray.
  3. Tack the surface lightly just before spraying; do not press hard or drag a dirty tack cloth.
🎬 Video demo + narration
Film this procedure (or build a narrated slideshow from the step images). Save as ase_b2a_finalclean_demo.mp4 in this category's images folder, then swap this box for a <video> player.
Narration script (read in order):
  1. Blow the panel and seams off with clean, dry air.
  2. Final-wipe with the correct cleaner for the coating you are about to spray.
  3. Tack the surface lightly just before spraying; do not press hard or drag a dirty tack cloth.
📷 Step-by-step image prompts — consistent series (generate in one session; reuse the same subject/style reference so every step matches)
Step 1 — save as ase_b2a_finalclean_s11.jpg: Create an image showing this exact step in an automotive refinishing lesson: Blow the panel and seams off with clean, dry air. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 2 — save as ase_b2a_finalclean_s21.jpg: Create an image showing this exact step in an automotive refinishing lesson: Final-wipe with the correct cleaner for the coating you are about to spray. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 3 — save as ase_b2a_finalclean_s31.jpg: Create an image showing this exact step in an automotive refinishing lesson: Tack the surface lightly just before spraying; do not press hard or drag a dirty tack cloth. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.

Remember: The last thing before paint is always: blow off, wipe, tack.

[VISUAL PLACEHOLDER] Grounding strap clipped to the vehicle to discharge static.
📷 Save image as: ase_b2a_static_electricity1.jpg  ·  prompt for labs.google.comCreate an image for an automotive refinishing training lesson. Subject: Grounding strap clipped to the vehicle to discharge static. Style: photorealistic high-resolution photograph, automotive body shop / paint booth setting, professional lighting, shallow depth of field, sharp detail, true-to-life color, no text, no watermark. Aspect ratio 16:9.

Control static electricity

ASE Surface Prep Task · A5"Remove and control static electricity on the surface to be refinished."What it means: discharge the static charge that pulls dust onto the panel, especially on plastic parts.
Key pointsStatic charge pulls dust onto the panel, especially plastic parts. A dry tack cloth does not discharge it; grounding does.
How to Do It (Step by Step)
  1. Connect a grounding strap or jumper from the vehicle body to a good ground.
  2. Use anti-static cleaners or wipes made for plastic where needed.
  3. Keep the booth clean and humidity controlled to reduce static build-up.
🎬 Video demo + narration
Film this procedure (or build a narrated slideshow from the step images). Save as ase_b2a_static_demo.mp4 in this category's images folder, then swap this box for a <video> player.
Narration script (read in order):
  1. Connect a grounding strap or jumper from the vehicle body to a good ground.
  2. Use anti-static cleaners or wipes made for plastic where needed.
  3. Keep the booth clean and humidity controlled to reduce static build-up.
📷 Step-by-step image prompts — consistent series (generate in one session; reuse the same subject/style reference so every step matches)
Step 1 — save as ase_b2a_static_s11.jpg: Create an image showing this exact step in an automotive refinishing lesson: Connect a grounding strap or jumper from the vehicle body to a good ground. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 2 — save as ase_b2a_static_s21.jpg: Create an image showing this exact step in an automotive refinishing lesson: Use anti-static cleaners or wipes made for plastic where needed. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 3 — save as ase_b2a_static_s31.jpg: Create an image showing this exact step in an automotive refinishing lesson: Keep the booth clean and humidity controlled to reduce static build-up. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.

Remember: Dust clinging to a bumper is usually static. Ground it, do not just wipe it.

Check what you learned

Final clean & tack / static

A tech notices dust strongly attracted to a plastic bumper cover during prep. What is an approved method to control it?

Connect a grounding jumper. The dust is held by static charge. Grounding the vehicle discharges it; a dry rag just moves it around.

Static

Static has built up on a body during prep. Painter A says wipe it down with a dry tack cloth to discharge it. Painter B says use a grounding/anti-static method. Who is right?

Painter B only. A dry tack cloth does not remove a static charge and can even add to it. Grounding and anti-static products discharge it.

# Numbers & Specs for this module

Film build / strip threshold: total paint build should not exceed about 12 mils; the common strip threshold is 12 to 14 mils. One mil = 0.001 inch ≈ 25 microns. Read it with an electronic mil gauge in several spots.

Cleaning order & method: clean with a waterborne cleaner first, then a solvent-based wax & grease remover, always using the two-cloth method with lint-free towels. Clean before sanding and again before coating. Verify products on the data sheet.

🔧 Practice in the Lab

1. Clean a panel the right way

GoalGet a panel truly clean so paint will bond, using the correct cleaners in the correct order and the two-cloth method.
ProductsNo-wax car wash soap, a waterborne surface cleaner, a solvent-based wax & grease remover, and lint-free towels.
Two-cloth methodApply the cleaner with one folded lint-free towel, then wipe it off with a second clean, dry lint-free towel before it flashes (dries). Work a small area at a time and turn to a fresh towel face often. Never let cleaner air-dry on the panel, it just redeposits the contamination.
How to Do It (Step by Step)
  1. Wash the panel with no-wax soap and water, rinse, and dry.
  2. Clean first with a waterborne cleaner — it removes water-soluble contamination (salt, sweat, fingerprints). Two-cloth method: apply with one lint-free towel, wipe with a clean dry one before it dries.
  3. Then clean with a solvent-based wax & grease remover — it removes oil, wax, silicone, and tar. Same two-cloth method.
  4. Wipe in one direction, not circles, and change towels often.
  5. Do a final clean and tack off right before you coat.
🎬 Video demo + narration
Film this procedure (or build a narrated slideshow from the step images). Save as ase_b2a_demo_demo.mp4 in this category's images folder, then swap this box for a <video> player.
Narration script (read in order):
  1. Wash the panel with no-wax soap and water, rinse, and dry.
  2. Clean first with a waterborne cleaner — it removes water-soluble contamination ( salt, sweat, fingerprints ). Two-cloth method: apply with one lint-free towel, wipe with a clean dry one before it dries.
  3. Then clean with a solvent-based wax & grease remover — it removes oil, wax, silicone, and tar . Same two-cloth method.
  4. Wipe in one direction , not circles, and change towels often.
  5. Do a final clean and tack off right before you coat.
📷 Step-by-step image prompts — consistent series (generate in one session; reuse the same subject/style reference so every step matches)
Step 1 — save as ase_b2a_step_s11.jpg: Create an image showing this exact step in an automotive refinishing lesson: Wash the panel with no-wax soap and water, rinse, and dry. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 2 — save as ase_b2a_step_s21.jpg: Create an image showing this exact step in an automotive refinishing lesson: Clean first with a waterborne cleaner — it removes water-soluble contamination ( salt, sweat, fingerprints ). Two-cloth method: apply with one lint-free towel, wipe with a clean dry one before it dries. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 3 — save as ase_b2a_step_s31.jpg: Create an image showing this exact step in an automotive refinishing lesson: Then clean with a solvent-based wax & grease remover — it removes oil, wax, silicone, and tar . Same two-cloth method. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 4 — save as ase_b2a_step_s41.jpg: Create an image showing this exact step in an automotive refinishing lesson: Wipe in one direction , not circles, and change towels often. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 5 — save as ase_b2a_step_s51.jpg: Create an image showing this exact step in an automotive refinishing lesson: Do a final clean and tack off right before you coat. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Why both, in this orderWaterborne and solvent cleaners remove different contaminants. Use only one and you leave half the contamination behind, which causes fish-eyes and adhesion failure.
Skill checkNo water-break on the surface, you cleaned waterborne then solvent with the two-cloth method on clean lint-free towels, and you cleaned before sanding.

2. Inspect and measure film build

GoalRead film build with an electronic mil gauge and decide repair vs. strip.
Skill checkYou take readings in several spots and correctly call under ~12 mils → prep and recoat, over ~12 mils → strip.

3. Control static

GoalGround the vehicle and use an anti-static wipe so dust stops clinging to plastic.
Skill checkYou ground the body instead of only wiping with a dry tack cloth, and dust release improves.
Module 2 of 4

Strip, Sand & Featheredge

[VISUAL PLACEHOLDER] Module 2 banner: DA sander featheredging a repair, grit progression laid out.
📷 Save image as: ase_b2a_m2_banner1.jpg  ·  prompt for labs.google.comCreate an image for an automotive refinishing training lesson. Subject: Module 2 banner: DA sander featheredging a repair, grit progression laid out. Style: clean modern vector infographic illustration, flat design, clearly labeled, high-contrast, white background, instructional, no watermark. Aspect ratio 16:9.

STRIP, SAND & FEATHEREDGE (The 30-second Lesson Overview)

Remove the finishSand, grind, or chemically strip old paint when needed. Stripper is caustic, so respect the hazards.
SandCoarse to fine. Cut and shape with coarser grit, then step up so the final scratch will be hidden.
FeatheredgeTaper the edges of each paint layer so the repair has no step. Keep each layer at least ~1/2 inch wide.
Block sandUse a block and a guide coat to find highs and lows and get the primer truly flat.
Goal: remove finish safely, sand with the right grit progression, featheredge so repairs do not telegraph, and block sand flat.
💡 Did you know? Sandpaper grit numbers come from a screen: a P80 abrasive is graded through a mesh with about 80 openings per inch, and P400 through about 400. Higher number means more, finer particles, so a smaller scratch.
!

Safety first

The skills

[VISUAL PLACEHOLDER] Three removal methods: DA sanding, grinding, chemical stripping.
📷 Save image as: ase_b2a_paint_finish1.jpg  ·  prompt for labs.google.comCreate an image for an automotive refinishing training lesson. Subject: Three removal methods: DA sanding, grinding, chemical stripping. Style: photorealistic high-resolution photograph, automotive body shop / paint booth setting, professional lighting, shallow depth of field, sharp detail, true-to-life color, no text, no watermark. Aspect ratio 16:9.

Remove the paint finish

ASE Surface Prep Task · A6"Remove paint finish as needed."What it means: strip the old coating, by sanding, grinding, blasting, or chemical stripper, when the panel cannot be saved by prepping over it.
Key pointsPick the least aggressive method that does the job for that substrate, and keep the metal cool and flat so you do not warp or stretch it. The four ways to remove a finish:
  • Mechanical — DA sander or grinder
  • Media blasting
  • Soda blasting
  • Chemical stripper
Tools & supplies6-inch dual-action (DA) sander with a soft interface pad, high-speed grinder/disc sander for heavy material, media or soda blaster, chemical (aircraft) stripper with a plastic scraper, sanding blocks, dust extraction or a vacuum, and PPE: particulate respirator, gloves, eye and ear protection.
Grits & methodsOn a DA: 36-grit removes all coatings fast, 40-grit removes all coatings, then 80-grit to shape any filler and 180-grit to take out the 80-grit scratches. Grinder discs (zirconia/aluminum oxide) for weld beads and heavy rust. Media/soda blasting takes coating to bare metal with no sanding heat, good for thin panels that warp. Chemical aircraft stripper makes no dust but burns skin, gives off toxic fumes, and leaves hazardous runoff. (Verify grits and products on the abrasive and stripper data sheets.)
Technique & best practiceKeep the DA flat at a low angle with a soft pad and let the tool cut; do not lean on it. Avoid heat and aggressive grinding on thin or aluminum panels. Never use discs on aluminum that were used on steel, the cross-contamination starts corrosion. Bare metal flash-rusts, so treat and prime it the same day.
How to Do It (Step by Step)
  1. Choose the method for the substrate (mechanical for most steel, blasting for warp-prone panels, chemical where heat is a problem).
  2. For DA removal, cut the coating with 36 to 40 grit, then shape filler with 80 and clean up the scratches with 180.
  3. If chemical stripping, mask surrounding areas, apply per the label, let it dwell, scrape, then neutralize and capture the runoff as hazardous waste.
  4. Keep the panel flat and cool; check often so you do not grind through good metal.
  5. Treat and prime any bare metal promptly.
🎬 Video demo + narration
Film this procedure (or build a narrated slideshow from the step images). Save as ase_b2a_demo_demo.mp4 in this category's images folder, then swap this box for a <video> player.
Narration script (read in order):
  1. Choose the method for the substrate (mechanical for most steel, blasting for warp-prone panels, chemical where heat is a problem).
  2. For DA removal, cut the coating with 36 to 40 grit, then shape filler with 80 and clean up the scratches with 180.
  3. If chemical stripping, mask surrounding areas, apply per the label, let it dwell, scrape, then neutralize and capture the runoff as hazardous waste.
  4. Keep the panel flat and cool; check often so you do not grind through good metal.
  5. Treat and prime any bare metal promptly.
📷 Step-by-step image prompts — consistent series (generate in one session; reuse the same subject/style reference so every step matches)
Step 1 — save as ase_b2a_step_s11.jpg: Create an image showing this exact step in an automotive refinishing lesson: Choose the method for the substrate (mechanical for most steel, blasting for warp-prone panels, chemical where heat is a problem). CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 2 — save as ase_b2a_step_s21.jpg: Create an image showing this exact step in an automotive refinishing lesson: For DA removal, cut the coating with 36 to 40 grit, then shape filler with 80 and clean up the scratches with 180. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 3 — save as ase_b2a_step_s31.jpg: Create an image showing this exact step in an automotive refinishing lesson: If chemical stripping, mask surrounding areas, apply per the label, let it dwell, scrape, then neutralize and capture the runoff as hazardous waste. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 4 — save as ase_b2a_step_s41.jpg: Create an image showing this exact step in an automotive refinishing lesson: Keep the panel flat and cool; check often so you do not grind through good metal. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 5 — save as ase_b2a_step_s51.jpg: Create an image showing this exact step in an automotive refinishing lesson: Treat and prime any bare metal promptly. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.

Remember: Match the method to the substrate. 36 to 40 grit strips fast; keep the DA flat, the metal cool, and prime bare metal the same day.

[VISUAL PLACEHOLDER] Grit progression chart: cut grits up to finish grits.
📷 Save image as: ase_b2a_sand1.jpg  ·  prompt for labs.google.comCreate an image for an automotive refinishing training lesson. Subject: Grit progression chart: cut grits up to finish grits. Style: clean modern vector infographic illustration, flat design, clearly labeled, high-contrast, white background, instructional, no watermark. Aspect ratio 16:9.

Sand areas to be refinished

ASE Surface Prep Task · A7"Dry or wet sand areas to be refinished."What it means: cut and smooth the surface with the right abrasive and grit so the next coat bonds and hides.
Key pointsSand coarse to fine, never skipping more than a grade or two. Coarser grit cuts and shapes; finer grit leaves a scratch small enough for the next coat to fill and hide. The abrasive material matters too: aluminum oxide for general sanding and primer, silicon carbide for wet sanding and paint.
Tools & suppliesDA sander with a soft, thick interface pad, sanding blocks, hand pads and sponges; P-grade (FEPA) paper; and scuff pads matched to the job: red/maroon pad (about 320 to 400 grit) for aggressive scuffing and new parts, gray pad (about 800 to 1000) for blend areas and prepping plastic, white/gold pad (about 1200 to 1500) for light scuffing.
Grits & progressionShape filler at 80-grit, take out the 80 scratches with 180, then step up. Final sand before sealer or basecoat: dry with a DA, P400 is best (P360 acceptable); dry by hand, P500 (or P400); wet by hand or machine, P600 is best (P500 good). Going dry to wet, drop two grades finer because wet cuts more aggressively; going machine to hand, drop one grade finer. (Confirm final grit on the paint maker's data sheet.)
Technique & best practiceSand in one direction, with the length of the panel; circles or cross-strokes leave marks that show and are hard to buff out. Run the DA at a low, flat angle with light pressure and lower speed; high pressure and speed cause rework. Turn the DA speed down near body lines. Clean with wax and grease remover before and after. Wet sand with clean, running water, never dirty bucket water. Use a guide coat so you do not oversand.
How to Do It (Step by Step)
  1. Pick the starting grit for the job: 80 to shape filler, 180 to clean up, finer to scuff for coating.
  2. Step up through the grits in order so each one removes the last one's scratches.
  3. Keep the DA flat and light, sanding with the length of the panel; slow down at body lines.
  4. Keep paper and surface clean; for wet sanding use plenty of clean water.
  5. Finish at the grit your next coat calls for (commonly P400 dry by machine to P600 wet).
🎬 Video demo + narration
Film this procedure (or build a narrated slideshow from the step images). Save as ase_b2a_demo_demo.mp4 in this category's images folder, then swap this box for a <video> player.
Narration script (read in order):
  1. Pick the starting grit for the job: 80 to shape filler, 180 to clean up, finer to scuff for coating.
  2. Step up through the grits in order so each one removes the last one's scratches.
  3. Keep the DA flat and light, sanding with the length of the panel; slow down at body lines.
  4. Keep paper and surface clean; for wet sanding use plenty of clean water.
  5. Finish at the grit your next coat calls for (commonly P400 dry by machine to P600 wet).
📷 Step-by-step image prompts — consistent series (generate in one session; reuse the same subject/style reference so every step matches)
Step 1 — save as ase_b2a_step_s11.jpg: Create an image showing this exact step in an automotive refinishing lesson: Pick the starting grit for the job: 80 to shape filler, 180 to clean up, finer to scuff for coating. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 2 — save as ase_b2a_step_s21.jpg: Create an image showing this exact step in an automotive refinishing lesson: Step up through the grits in order so each one removes the last one's scratches. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 3 — save as ase_b2a_step_s31.jpg: Create an image showing this exact step in an automotive refinishing lesson: Keep the DA flat and light, sanding with the length of the panel; slow down at body lines. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 4 — save as ase_b2a_step_s41.jpg: Create an image showing this exact step in an automotive refinishing lesson: Keep paper and surface clean; for wet sanding use plenty of clean water. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 5 — save as ase_b2a_step_s51.jpg: Create an image showing this exact step in an automotive refinishing lesson: Finish at the grit your next coat calls for (commonly P400 dry by machine to P600 wet). CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.

Remember: Coarse cuts, fine finishes. Sand with the length of the panel, DA flat and light, and step the grits, do not jump them.

[VISUAL PLACEHOLDER] Cross-section of a featheredge: bare metal tapering up through primer and paint.
📷 Save image as: ase_b2a_featheredge_repair1.jpg  ·  prompt for labs.google.comCreate an image for an automotive refinishing training lesson. Subject: Cross-section of a featheredge: bare metal tapering up through primer and paint. Style: clean modern vector infographic illustration, flat design, clearly labeled, high-contrast, white background, instructional, no watermark. Aspect ratio 16:9.

Featheredge the repair

ASE Surface Prep Task · A8"Featheredge areas to be refinished."What it means: taper the broken paint edges around a repair so there is no step to telegraph through the new finish.
Key pointsFeatheredging tapers the edges of the paint layers around a repair so there is no visible step. Body filler and the area are first leveled with 150-grit; the featheredge process then refines that edge for primer. Each exposed layer (clear, color, primer, e-coat, bare metal) should show as a ring at least about 1/2 inch wide.
Tools & suppliesPneumatic DA sander or a hand sanding block, aluminum oxide paper, a red scuff pad with water and blend prep, clean compressed air, and a tack rag.
Sandpaper & gritAfter the filler and area are leveled with 150-grit, featheredge with 180-grit, then 220-grit, then 320-grit on a DA or block. 320 is the featheredge finish grit, fine enough to prime over. (This is the industry feather, prime and block sequence; confirm grits against your paint system.)
Technique & best practiceKeep the DA at a low, flat angle with a soft pad, or work by hand on a block, and sand the edges into a long, gradual taper, not a steep cliff. Featheredge slightly larger than the area the primer will cover. Step 180 to 220 to 320 so the last scratch is fine. Scuff the surrounding panel with a red scuff pad and water. Check by dragging a fingernail or a microfiber across it, you should feel no ridge, and look for pinholes.
How to Do It (Step by Step)
  1. Confirm the filler and area are leveled to 150-grit first.
  2. Featheredge the broken paint edges with 180, then 220, then 320 grit, taking each layer out into a wide taper.
  3. Keep each layer of the featheredge at least ~1/2 inch wide so it will not map.
  4. Scuff the surrounding panel, then check by feel and sight; you should not feel a ridge.
  5. Blow off, wipe, and clean before priming.
🎬 Video demo + narration
Film this procedure (or build a narrated slideshow from the step images). Save as ase_b2a_demo_demo.mp4 in this category's images folder, then swap this box for a <video> player.
Narration script (read in order):
  1. Confirm the filler and area are leveled to 150-grit first.
  2. Featheredge the broken paint edges with 180, then 220, then 320 grit, taking each layer out into a wide taper.
  3. Keep each layer of the featheredge at least ~1/2 inch wide so it will not map.
  4. Scuff the surrounding panel, then check by feel and sight; you should not feel a ridge.
  5. Blow off, wipe, and clean before priming.
📷 Step-by-step image prompts — consistent series (generate in one session; reuse the same subject/style reference so every step matches)
Step 1 — save as ase_b2a_step_s11.jpg: Create an image showing this exact step in an automotive refinishing lesson: Confirm the filler and area are leveled to 150-grit first. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 2 — save as ase_b2a_step_s21.jpg: Create an image showing this exact step in an automotive refinishing lesson: Featheredge the broken paint edges with 180, then 220, then 320 grit, taking each layer out into a wide taper. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 3 — save as ase_b2a_step_s31.jpg: Create an image showing this exact step in an automotive refinishing lesson: Keep each layer of the featheredge at least ~1/2 inch wide so it will not map. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 4 — save as ase_b2a_step_s41.jpg: Create an image showing this exact step in an automotive refinishing lesson: Scuff the surrounding panel, then check by feel and sight; you should not feel a ridge. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 5 — save as ase_b2a_step_s51.jpg: Create an image showing this exact step in an automotive refinishing lesson: Blow off, wipe, and clean before priming. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.

Remember: Level to 150, then featheredge 180 to 220 to 320. Each layer at least 1/2 inch wide, with no ridge you can feel.

[VISUAL PLACEHOLDER] Block sanding primer with a guide coat showing lows.
📷 Save image as: ase_b2a_block_sand_primer1.jpg  ·  prompt for labs.google.comCreate an image for an automotive refinishing training lesson. Subject: Block sanding primer with a guide coat showing lows. Style: photorealistic high-resolution photograph, automotive body shop / paint booth setting, professional lighting, shallow depth of field, sharp detail, true-to-life color, no text, no watermark. Aspect ratio 16:9.

Block sand primer & filler

ASE Surface Prep Task · A9"Block sand the area to which primer-surfacer has been applied."What it means: level the cured primer dead flat with a block and a guide coat before sealer and color.
Key pointsA flat sanding block plus a guide coat finds highs and lows that a hand or DA will miss, and gets the primer truly flat before sealer and color. Block sanding is done over cured primer-surfacer, usually wet, so the surface comes out level with the surrounding paint.
Tools & suppliesFirm flat blocks and long boards (durablocks) for flat panels, flexible or foam blocks for curves, guide coat (dry guide-coat powder or a light dust of a contrasting color), a spray bottle or hose for wet sanding, and P-grade silicon-carbide wet paper. Use the longest block the panel will allow.
Grit & techniqueGuide coat the cured primer, then block 220 wet, then 320 wet. Refinish-level final sanding starts at 400 wet, so finish to the grit the sealer or topcoat calls for (commonly P400 to P600). Cross-block in an X pattern at angles to level the surface, with the final strokes lengthwise (with the panel). The guide coat stays in the lows and disappears on the highs. (Confirm the final grit on the paint maker's data sheet.)
Best practiceEven pressure, let the block find the highs; do not rock it. Wet sand with a spray bottle or hose and clean running water, never a dirty bucket whose sludge will scratch the panel. Leave masking in place to keep sludge out of crevices. A guide coat prevents oversanding and shows missed spots. If you break through to filler or bare metal, re-prime that spot.
How to Do It (Step by Step)
  1. Apply a guide coat over the cured primer-surfacer.
  2. Cross-block 220 wet, then 320 wet, in an X pattern, with clean running water; finish strokes lengthwise.
  3. Read the guide coat: it stays in the lows and disappears on the highs.
  4. Re-prime and re-block if lows or pinholes remain.
  5. Finish-sand to the grit the sealer or topcoat needs (P400 to P600).
🎬 Video demo + narration
Film this procedure (or build a narrated slideshow from the step images). Save as ase_b2a_demo_demo.mp4 in this category's images folder, then swap this box for a <video> player.
Narration script (read in order):
  1. Apply a guide coat over the cured primer-surfacer.
  2. Cross-block 220 wet, then 320 wet, in an X pattern, with clean running water; finish strokes lengthwise.
  3. Read the guide coat: it stays in the lows and disappears on the highs.
  4. Re-prime and re-block if lows or pinholes remain.
  5. Finish-sand to the grit the sealer or topcoat needs (P400 to P600).
📷 Step-by-step image prompts — consistent series (generate in one session; reuse the same subject/style reference so every step matches)
Step 1 — save as ase_b2a_step_s11.jpg: Create an image showing this exact step in an automotive refinishing lesson: Apply a guide coat over the cured primer-surfacer. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 2 — save as ase_b2a_step_s21.jpg: Create an image showing this exact step in an automotive refinishing lesson: Cross-block 220 wet, then 320 wet, in an X pattern, with clean running water; finish strokes lengthwise. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 3 — save as ase_b2a_step_s31.jpg: Create an image showing this exact step in an automotive refinishing lesson: Read the guide coat: it stays in the lows and disappears on the highs. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 4 — save as ase_b2a_step_s41.jpg: Create an image showing this exact step in an automotive refinishing lesson: Re-prime and re-block if lows or pinholes remain. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 5 — save as ase_b2a_step_s51.jpg: Create an image showing this exact step in an automotive refinishing lesson: Finish-sand to the grit the sealer or topcoat needs (P400 to P600). CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.

Remember: Guide coat, then block. Cross-block 220 then 320 wet, finish strokes lengthwise, and let the block tell the truth about flat.

Check what you learned

Remove the finish

Using a chemical aircraft stripper to remove automotive finishes presents all of the following hazards EXCEPT:

Airborne dust. Chemical stripping dissolves the paint, so it does not throw dust like sanding does. The real hazards are burns, fumes, and runoff.

Featheredge

To prevent repair mapping, what is the minimum acceptable width for each individual paint layer in a sanded featheredge?

One half inch. Each layer needs roughly a half inch of taper so the transition is gradual enough not to telegraph through the finish.

# Numbers & Specs for this module

Grit progression (verify on the abrasive and paint data sheets): 36 to 40 grit strips all coatings; 80 shapes filler; 180 removes the 80-grit scratches. Level bodywork to 150 before featheredging. Featheredge 180 → 220 → 320. Block sand primer 220 wet → 320 wet. Final sand before sealer/base: P400 dry (DA), P500 dry (hand), or P600 wet. Never skip grits.

Scuff pads: red/maroon ≈ 320–400 (aggressive scuff/new parts); gray ≈ 800–1000 (blend areas, plastic); white/gold ≈ 1200–1500 (light scuff). Abrasive material: aluminum oxide for general sanding and primer; silicon carbide for wet sanding and paint.

Featheredge width: keep each paint layer at least about 1/2 inch wide so the repair does not map.

🔧 Practice in the Lab

1. Remove a finish without warping the metal

GoalStrip a panel with a DA sander kept flat and cool, or by chemical stripper, without warping or stretching the metal.
Skill checkCoating is gone to a sound layer, the panel is still flat and cool, and bare metal was treated and primed the same day.

2. Featheredge a repair

GoalFeatheredge a chip/repair through 180 → 220 → 320 so each layer is at least ~1/2 inch wide.
Skill checkA fingernail dragged across feels no step; the layers are visible and gradual.

3. Grit-progression drill

GoalLay out sandpaper in the correct order for a job and explain why you never skip a grit.
Skill checkYou step coarse to fine in order and finish at the grit the next coat calls for (P400 dry to P600 wet).
Module 3 of 4

Treat, Prime & Fill

[VISUAL PLACEHOLDER] Module 3 banner: spraying primer-surfacer; self-etch on bare metal; glaze over a low spot.
📷 Save image as: ase_b2a_m3_banner1.jpg  ·  prompt for labs.google.comCreate an image for an automotive refinishing training lesson. Subject: Module 3 banner: spraying primer-surfacer; self-etch on bare metal; glaze over a low spot. Style: clean modern vector infographic illustration, flat design, clearly labeled, high-contrast, white background, instructional, no watermark. Aspect ratio 16:9.

TREAT, PRIME & FILL (The 30-second Lesson Overview)

Treat the substrateBare steel/aluminum/galvanized get self-etch or a conversion coating; plastics get adhesion promoter; composites usually do not need self-etch.
Primer-surfacerA high-build 2K urethane undercoat that fills sand scratches and small imperfections, then gets block sanded.
Finishing filler (glaze)A thin putty for minor pinholes and low spots after primer, sanded smooth.
Primer-sealerSeals the surface, blocks solvent penetration, gives a uniform ground color, and improves adhesion. It does not fill deep scratches.
Find pinholesA guide coat and block sanding reveal pinholes and lows after primer.
Goal: choose the right treatment for the substrate, apply and sand primer-surfacer, fill minor imperfections, seal correctly, and catch pinholes before paint.
💡 Did you know? Self-etching primer contains a mild acid (usually phosphoric) that micro-etches bare metal so the paint can grip. It is chemistry doing part of the sanding for you, which is why it goes straight on clean bare metal.
!

Safety first

The skills

[VISUAL PLACEHOLDER] Substrate chart: steel, aluminum, galvanized, plastic, composite, with correct treatment.
📷 Save image as: ase_b2a_substrate_treatment1.jpg  ·  prompt for labs.google.comCreate an image for an automotive refinishing training lesson. Subject: Substrate chart: steel, aluminum, galvanized, plastic, composite, with correct treatment. Style: clean modern vector infographic illustration, flat design, clearly labeled, high-contrast, white background, instructional, no watermark. Aspect ratio 16:9.

Identify the substrate & apply the right treatment

ASE Surface Prep Task · A10"Apply a suitable metal treatment, conversion coating, or self-etching primer according to product directions."What it means: treat each bare substrate so the coating bites in and corrosion is stopped before primer.
Key pointsBare steel, aluminum, and galvanized need a self-etching primer or conversion coating to bite and resist corrosion. Plastics need an adhesion promoter. Carbon fiber and fiberglass composites generally do not need self-etch.
How to Do It (Step by Step)
  1. Identify the bare substrate.
  2. Clean it for that material (plastic cleaner for plastic, etc.).
  3. Apply the correct treatment: self-etch/conversion for bare metals, adhesion promoter for plastics.
  4. Follow with the proper undercoat per the TDS.
🎬 Video demo + narration
Film this procedure (or build a narrated slideshow from the step images). Save as ase_b2a_substrate_demo.mp4 in this category's images folder, then swap this box for a <video> player.
Narration script (read in order):
  1. Identify the bare substrate.
  2. Clean it for that material (plastic cleaner for plastic, etc.).
  3. Apply the correct treatment: self-etch/conversion for bare metals, adhesion promoter for plastics.
  4. Follow with the proper undercoat per the TDS.
📷 Step-by-step image prompts — consistent series (generate in one session; reuse the same subject/style reference so every step matches)
Step 1 — save as ase_b2a_substrate_s11.jpg: Create an image showing this exact step in an automotive refinishing lesson: Identify the bare substrate. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 2 — save as ase_b2a_substrate_s21.jpg: Create an image showing this exact step in an automotive refinishing lesson: Clean it for that material (plastic cleaner for plastic, etc.). CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 3 — save as ase_b2a_substrate_s31.jpg: Create an image showing this exact step in an automotive refinishing lesson: Apply the correct treatment: self-etch/conversion for bare metals, adhesion promoter for plastics. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 4 — save as ase_b2a_substrate_s41.jpg: Create an image showing this exact step in an automotive refinishing lesson: Follow with the proper undercoat per the TDS. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.

Remember: Bare metal needs etch; plastic needs adhesion promoter; composite usually needs neither.

[VISUAL PLACEHOLDER] Spraying even coats of 2K primer-surfacer with flash between coats.
📷 Save image as: ase_b2a_primer_surfacer1.jpg  ·  prompt for labs.google.comCreate an image for an automotive refinishing training lesson. Subject: Spraying even coats of 2K primer-surfacer with flash between coats. Style: photorealistic high-resolution photograph, automotive body shop / paint booth setting, professional lighting, shallow depth of field, sharp detail, true-to-life color, no text, no watermark. Aspect ratio 16:9.

Mix & apply primer-surfacer

ASE Surface Prep Task · A11"Mix and apply primer, primer-surfacer, or primer-sealer."What it means: mix to the exact ratio and lay down the high-build undercoat that fills sand scratches and is made to be block sanded.
Key pointsHigh-build 2K urethane primer-surfacer fills fine sand scratches and minor imperfections and is meant to be block sanded flat. Apply in proper coats with full flash between them.
How to Do It (Step by Step)
  1. Mix to the exact ratio on the TDS with the correct activator and reducer.
  2. Apply medium, even coats, allowing full flash time between coats so solvent escapes.
  3. Let it cure before sanding so it will not keep shrinking.
  4. Block sand flat with a guide coat.
🎬 Video demo + narration
Film this procedure (or build a narrated slideshow from the step images). Save as ase_b2a_primer_demo.mp4 in this category's images folder, then swap this box for a <video> player.
Narration script (read in order):
  1. Mix to the exact ratio on the TDS with the correct activator and reducer.
  2. Apply medium, even coats, allowing full flash time between coats so solvent escapes.
  3. Let it cure before sanding so it will not keep shrinking.
  4. Block sand flat with a guide coat.
📷 Step-by-step image prompts — consistent series (generate in one session; reuse the same subject/style reference so every step matches)
Step 1 — save as ase_b2a_primer_s11.jpg: Create an image showing this exact step in an automotive refinishing lesson: Mix to the exact ratio on the TDS with the correct activator and reducer. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 2 — save as ase_b2a_primer_s21.jpg: Create an image showing this exact step in an automotive refinishing lesson: Apply medium, even coats, allowing full flash time between coats so solvent escapes. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 3 — save as ase_b2a_primer_s31.jpg: Create an image showing this exact step in an automotive refinishing lesson: Let it cure before sanding so it will not keep shrinking. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 4 — save as ase_b2a_primer_s41.jpg: Create an image showing this exact step in an automotive refinishing lesson: Block sand flat with a guide coat. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.

Remember: Primer-surfacer is made to be sanded. Build it, flash it, cure it, block it.

[VISUAL PLACEHOLDER] Spreading thin glaze putty over pinholes/low spots on primer.
📷 Save image as: ase_b2a_finishing_filler_glaze1.jpg  ·  prompt for labs.google.comCreate an image for an automotive refinishing training lesson. Subject: Spreading thin glaze putty over pinholes/low spots on primer. Style: photorealistic high-resolution photograph, automotive body shop / paint booth setting, professional lighting, shallow depth of field, sharp detail, true-to-life color, no text, no watermark. Aspect ratio 16:9.

Apply finishing filler (glaze) to minor imperfections

ASE Surface Prep Task · A12"Apply two-component finishing filler (glaze) to minor surface imperfections."What it means: fill the small pinholes and shallow lows that primer alone will not fill, then sand smooth and re-prime.
Key pointsA thin finishing filler or glaze handles small chips, pinholes, and shallow lows that primer alone will not fill. It is sanded smooth, then re-primed.
How to Do It (Step by Step)
  1. Sand and clean the area.
  2. Spread a thin layer of finishing filler over the minor imperfections.
  3. Let it cure, then sand smooth and flat.
  4. Re-prime over the filled area.
🎬 Video demo + narration
Film this procedure (or build a narrated slideshow from the step images). Save as ase_b2a_glaze_demo.mp4 in this category's images folder, then swap this box for a <video> player.
Narration script (read in order):
  1. Sand and clean the area.
  2. Spread a thin layer of finishing filler over the minor imperfections.
  3. Let it cure, then sand smooth and flat.
  4. Re-prime over the filled area.
📷 Step-by-step image prompts — consistent series (generate in one session; reuse the same subject/style reference so every step matches)
Step 1 — save as ase_b2a_glaze_s11.jpg: Create an image showing this exact step in an automotive refinishing lesson: Sand and clean the area. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 2 — save as ase_b2a_glaze_s21.jpg: Create an image showing this exact step in an automotive refinishing lesson: Spread a thin layer of finishing filler over the minor imperfections. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 3 — save as ase_b2a_glaze_s31.jpg: Create an image showing this exact step in an automotive refinishing lesson: Let it cure, then sand smooth and flat. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 4 — save as ase_b2a_glaze_s41.jpg: Create an image showing this exact step in an automotive refinishing lesson: Re-prime over the filled area. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.

Remember: Glaze is for the small stuff after primer, not for fixing dents.

[VISUAL PLACEHOLDER] Spraying primer-sealer for a uniform ground color before basecoat.
📷 Save image as: ase_b2a_primer_sealer_adhesion1.jpg  ·  prompt for labs.google.comCreate an image for an automotive refinishing training lesson. Subject: Spraying primer-sealer for a uniform ground color before basecoat. Style: photorealistic high-resolution photograph, automotive body shop / paint booth setting, professional lighting, shallow depth of field, sharp detail, true-to-life color, no text, no watermark. Aspect ratio 16:9.

Apply primer-sealer & adhesion promoter

ASE Surface Prep Task · A13"Apply a suitable sealer to the surface prior to topcoat application."What it means: seal the surface and set an even ground color so the topcoat hides and bonds, without trying to fill scratches.
Key pointsA sealer locks down the surface: it stops topcoat solvents from soaking in, gives a uniform ground color so the color hides evenly, and improves adhesion. It is not a filler and will not bury deep sand scratches.
How to Do It (Step by Step)
  1. Finish-sand and clean the primer.
  2. Choose a sealer ground color that helps the topcoat hide.
  3. Apply per the TDS and respect the recoat window before basecoat.
  4. On hard-to-coat surfaces, use the correct adhesion promoter.
🎬 Video demo + narration
Film this procedure (or build a narrated slideshow from the step images). Save as ase_b2a_sealer_demo.mp4 in this category's images folder, then swap this box for a <video> player.
Narration script (read in order):
  1. Finish-sand and clean the primer.
  2. Choose a sealer ground color that helps the topcoat hide.
  3. Apply per the TDS and respect the recoat window before basecoat.
  4. On hard-to-coat surfaces, use the correct adhesion promoter.
📷 Step-by-step image prompts — consistent series (generate in one session; reuse the same subject/style reference so every step matches)
Step 1 — save as ase_b2a_sealer_s11.jpg: Create an image showing this exact step in an automotive refinishing lesson: Finish-sand and clean the primer. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 2 — save as ase_b2a_sealer_s21.jpg: Create an image showing this exact step in an automotive refinishing lesson: Choose a sealer ground color that helps the topcoat hide. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 3 — save as ase_b2a_sealer_s31.jpg: Create an image showing this exact step in an automotive refinishing lesson: Apply per the TDS and respect the recoat window before basecoat. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 4 — save as ase_b2a_sealer_s41.jpg: Create an image showing this exact step in an automotive refinishing lesson: On hard-to-coat surfaces, use the correct adhesion promoter. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.

Remember: Sealer seals and evens the ground color; it does not fill. Fix scratches before you seal.

[VISUAL PLACEHOLDER] Guide coat over primer revealing pinholes after a block-sanding pass.
📷 Save image as: ase_b2a_pinholes1.jpg  ·  prompt for labs.google.comCreate an image for an automotive refinishing training lesson. Subject: Guide coat over primer revealing pinholes after a block-sanding pass. Style: photorealistic high-resolution photograph, automotive body shop / paint booth setting, professional lighting, shallow depth of field, sharp detail, true-to-life color, no text, no watermark. Aspect ratio 16:9.

Identify & correct pinholes

ASE Surface Prep Task · A14"Apply a guide coat; identify and correct pinholes and minor surface imperfections."What it means: use a guide coat and a block to reveal and fix pinholes and lows before you spray color.
Key pointsAfter priming over filler, a guide coat and a flat block reveal pinholes, low spots, and shrinkage. Find them now, not after you spray color.
How to Do It (Step by Step)
  1. Apply a guide coat over the primer.
  2. Block sand with fine grit; pinholes and lows hold the guide coat.
  3. Fill pinholes with glaze, re-prime, and re-block.
  4. Confirm the surface is flat and pinhole-free before sealing.
🎬 Video demo + narration
Film this procedure (or build a narrated slideshow from the step images). Save as ase_b2a_pinholes_demo.mp4 in this category's images folder, then swap this box for a <video> player.
Narration script (read in order):
  1. Apply a guide coat over the primer.
  2. Block sand with fine grit; pinholes and lows hold the guide coat.
  3. Fill pinholes with glaze, re-prime, and re-block.
  4. Confirm the surface is flat and pinhole-free before sealing.
📷 Step-by-step image prompts — consistent series (generate in one session; reuse the same subject/style reference so every step matches)
Step 1 — save as ase_b2a_pinholes_s11.jpg: Create an image showing this exact step in an automotive refinishing lesson: Apply a guide coat over the primer. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 2 — save as ase_b2a_pinholes_s21.jpg: Create an image showing this exact step in an automotive refinishing lesson: Block sand with fine grit; pinholes and lows hold the guide coat. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 3 — save as ase_b2a_pinholes_s31.jpg: Create an image showing this exact step in an automotive refinishing lesson: Fill pinholes with glaze, re-prime, and re-block. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 4 — save as ase_b2a_pinholes_s41.jpg: Create an image showing this exact step in an automotive refinishing lesson: Confirm the surface is flat and pinhole-free before sealing. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.

Remember: A guide coat and a block find pinholes before the customer does.

Check what you learned

Substrate treatment

Which of these bare materials does NOT require a self-etching primer?

Carbon fiber or fiberglass. Composites do not need self-etch; bare metals do, to bite and resist corrosion.

Primer-sealer

All of the following are valid reasons to use a primer-sealer EXCEPT:

Filling deep sand scratches. Sealer is not a filler. Deep scratches must be sanded out or filled with primer-surfacer before sealing.

Find pinholes

After priming over a body-filler repair, which method is most likely used to find minor low spots, pinholes, and shrinkage?

Block sanding with a guide coat. The guide coat stays in the lows and pinholes as you block, showing exactly where to fill.

# Numbers & Specs for this module

Substrate treatment: bare steel, aluminum, and galvanized need self-etch primer or a conversion coating; plastics need an adhesion promoter; carbon fiber and fiberglass generally need neither.

Primer-surfacer: a high-build 2K urethane undercoat that fills fine sand scratches. Mix to the exact ratio, apply in even coats with full flash time, let it cure, then block sand.

Primer-sealer seals, gives a uniform ground color, and improves adhesion. It does NOT fill deep scratches. Always verify mix ratios, induction/flash times, and recoat windows on the product data sheet.

🔧 Practice in the Lab

1. Match the substrate to the treatment

GoalGiven steel, aluminum, plastic, and composite samples, name and apply the correct treatment for each.
Skill checkSelf-etch/conversion for the metals, adhesion promoter for plastic, neither for composite.

2. Mix and apply primer-surfacer

GoalMix 2K primer-surfacer to the exact ratio, spray even coats with proper flash, let it cure, then block.
Skill checkCorrect mix ratio, even build, full flash between coats, and it block-sands flat with no shrink-back.

3. Guide-coat, glaze & find pinholes

GoalApply a guide coat, block sand, then glaze any pinholes/lows and re-prime.
Skill checkGuide coat clears off the highs, lows and pinholes are found and filled, surface is flat before sealing.
Module 4 of 4

Mask, Protect & Coatings

[VISUAL PLACEHOLDER] Module 4 banner: masked vehicle, stone-chip coating on a rocker, trim removed for blending.
📷 Save image as: ase_b2a_m4_banner1.jpg  ·  prompt for labs.google.comCreate an image for an automotive refinishing training lesson. Subject: Module 4 banner: masked vehicle, stone-chip coating on a rocker, trim removed for blending. Style: clean modern vector infographic illustration, flat design, clearly labeled, high-contrast, white background, instructional, no watermark. Aspect ratio 16:9.

MASK, PROTECT & COATINGS (The 30-second Lesson Overview)

MaskingProtect everything you are not refinishing with paper, plastic, tape, or liquid mask. Mask to prevent overspray and hard edges.
Blend prepFor a blend, scuff the adjacent panel correctly; for full clear, remove trim and abrade edge to edge.
Stone-chip coatingTextured chip-resistant coating on rockers and lower panels, applied per the maker's instructions.
Corrosion coatingsRestore corrosion protection on repaired areas, including cavity wax inside closed panels.
Trim, decals, moldingsRemove or properly mask trim, and remove/replace decals, tapes, and pinstripes.
Goal: protect the rest of the vehicle, prepare adjacent panels for a clean blend, restore protective coatings, and handle trim and decals correctly.
💡 Did you know? Masking tape was invented for body shops. In 1925 a 3M engineer, Richard Drew, created it after watching painters struggle with two-tone car jobs. The auto refinish trade is literally where masking tape was born.
!

Safety first

The skills

[VISUAL PLACEHOLDER] A properly masked vehicle: paper, plastic, fine-line tape, liquid mask.
📷 Save image as: ase_b2a_mask_protect1.jpg  ·  prompt for labs.google.comCreate an image for an automotive refinishing training lesson. Subject: A properly masked vehicle: paper, plastic, fine-line tape, liquid mask. Style: photorealistic high-resolution photograph, automotive body shop / paint booth setting, professional lighting, shallow depth of field, sharp detail, true-to-life color, no text, no watermark. Aspect ratio 16:9.

Mask & protect areas that will not be refinished

ASE Surface Prep Task · A15"Mask and protect other areas and panels that will not be refinished."What it means: cover everything you are not painting so overspray and hard edges cannot ruin it.
Key pointsUse automotive masking paper, plastic sheeting, tape, and liquid mask as the barriers. Heavy canvas tarps are not a primary masking barrier. Mask wide enough to stop overspray and soft enough to avoid hard edges where you need a blend.
How to Do It (Step by Step)
  1. Clean first; tape does not stick to a dirty panel and can cause tracking.
  2. Mask the perimeter wide enough that overspray cannot reach unprotected surfaces.
  3. Use fine-line tape at paint edges and reverse/foam masking where you will blend.
  4. Cover glass, openings, and the engine bay with paper, plastic, or liquid mask.
🎬 Video demo + narration
Film this procedure (or build a narrated slideshow from the step images). Save as ase_b2a_mask_demo.mp4 in this category's images folder, then swap this box for a <video> player.
Narration script (read in order):
  1. Clean first; tape does not stick to a dirty panel and can cause tracking.
  2. Mask the perimeter wide enough that overspray cannot reach unprotected surfaces.
  3. Use fine-line tape at paint edges and reverse/foam masking where you will blend.
  4. Cover glass, openings, and the engine bay with paper, plastic, or liquid mask.
📷 Step-by-step image prompts — consistent series (generate in one session; reuse the same subject/style reference so every step matches)
Step 1 — save as ase_b2a_mask_s11.jpg: Create an image showing this exact step in an automotive refinishing lesson: Clean first; tape does not stick to a dirty panel and can cause tracking. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 2 — save as ase_b2a_mask_s21.jpg: Create an image showing this exact step in an automotive refinishing lesson: Mask the perimeter wide enough that overspray cannot reach unprotected surfaces. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 3 — save as ase_b2a_mask_s31.jpg: Create an image showing this exact step in an automotive refinishing lesson: Use fine-line tape at paint edges and reverse/foam masking where you will blend. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 4 — save as ase_b2a_mask_s41.jpg: Create an image showing this exact step in an automotive refinishing lesson: Cover glass, openings, and the engine bay with paper, plastic, or liquid mask. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.

Remember: Mask wide to stop overspray, mask soft where you blend.

[VISUAL PLACEHOLDER] Adjacent panel scuffed edge-to-edge with trim removed for a clear blend.
📷 Save image as: ase_b2a_adjacent_blending1.jpg  ·  prompt for labs.google.comCreate an image for an automotive refinishing training lesson. Subject: Adjacent panel scuffed edge-to-edge with trim removed for a clear blend. Style: photorealistic high-resolution photograph, automotive body shop / paint booth setting, professional lighting, shallow depth of field, sharp detail, true-to-life color, no text, no watermark. Aspect ratio 16:9.

Prepare adjacent areas for blending

ASE Surface Prep Task · A16"Identify and prepare adjacent panels and other areas for blending."What it means: scuff and prep the next panel edge to edge so a basecoat blend and clearcoat go on invisibly.
Key pointsFor a basecoat blend with full clear over the adjacent panel, remove the trim and abrade the entire surface edge to edge so the clear has a bond everywhere it lands.
How to Do It (Step by Step)
  1. Remove trim pieces rather than masking over them where possible.
  2. Scuff the whole adjacent surface that the clear will cover, edge to edge, with a fine scuff pad/grit.
  3. Clean and tack.
  4. Plan the blend area so the color fades out before the clear edge.
🎬 Video demo + narration
Film this procedure (or build a narrated slideshow from the step images). Save as ase_b2a_blendprep_demo.mp4 in this category's images folder, then swap this box for a <video> player.
Narration script (read in order):
  1. Remove trim pieces rather than masking over them where possible.
  2. Scuff the whole adjacent surface that the clear will cover, edge to edge, with a fine scuff pad/grit.
  3. Clean and tack.
  4. Plan the blend area so the color fades out before the clear edge.
📷 Step-by-step image prompts — consistent series (generate in one session; reuse the same subject/style reference so every step matches)
Step 1 — save as ase_b2a_blendprep_s11.jpg: Create an image showing this exact step in an automotive refinishing lesson: Remove trim pieces rather than masking over them where possible. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 2 — save as ase_b2a_blendprep_s21.jpg: Create an image showing this exact step in an automotive refinishing lesson: Scuff the whole adjacent surface that the clear will cover, edge to edge, with a fine scuff pad/grit. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 3 — save as ase_b2a_blendprep_s31.jpg: Create an image showing this exact step in an automotive refinishing lesson: Clean and tack. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 4 — save as ase_b2a_blendprep_s41.jpg: Create an image showing this exact step in an automotive refinishing lesson: Plan the blend area so the color fades out before the clear edge. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.

Remember: Clear has to grip everywhere it lands, so scuff the whole panel, not just the blend zone.

[VISUAL PLACEHOLDER] Textured stone-chip coating sprayed on a lower rocker panel.
📷 Save image as: ase_b2a_stone_chip_coating1.jpg  ·  prompt for labs.google.comCreate an image for an automotive refinishing training lesson. Subject: Textured stone-chip coating sprayed on a lower rocker panel. Style: photorealistic high-resolution photograph, automotive body shop / paint booth setting, professional lighting, shallow depth of field, sharp detail, true-to-life color, no text, no watermark. Aspect ratio 16:9.

Apply stone-chip resistant coating

ASE Surface Prep Task · A17"Apply stone chip-resistant coating."What it means: restore the textured chip-guard on rockers and lower panels, matched to the factory texture per the product.
Key pointsTextured chip-resistant coatings protect rockers and lower panels from road debris. They are applied following the specific product maker's instructions, not mixed into the basecoat or sprayed over the final clear.
How to Do It (Step by Step)
  1. Prep and prime the area as the product requires.
  2. Mask the texture line cleanly.
  3. Apply the chip-guard coating per the maker's instructions to match the factory texture.
  4. Topcoat as directed if the product is paintable.
🎬 Video demo + narration
Film this procedure (or build a narrated slideshow from the step images). Save as ase_b2a_stonechip_demo.mp4 in this category's images folder, then swap this box for a <video> player.
Narration script (read in order):
  1. Prep and prime the area as the product requires.
  2. Mask the texture line cleanly.
  3. Apply the chip-guard coating per the maker's instructions to match the factory texture.
  4. Topcoat as directed if the product is paintable.
📷 Step-by-step image prompts — consistent series (generate in one session; reuse the same subject/style reference so every step matches)
Step 1 — save as ase_b2a_stonechip_s11.jpg: Create an image showing this exact step in an automotive refinishing lesson: Prep and prime the area as the product requires. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 2 — save as ase_b2a_stonechip_s21.jpg: Create an image showing this exact step in an automotive refinishing lesson: Mask the texture line cleanly. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 3 — save as ase_b2a_stonechip_s31.jpg: Create an image showing this exact step in an automotive refinishing lesson: Apply the chip-guard coating per the maker's instructions to match the factory texture. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 4 — save as ase_b2a_stonechip_s41.jpg: Create an image showing this exact step in an automotive refinishing lesson: Topcoat as directed if the product is paintable. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.

Remember: Chip-guard goes on per the product instructions and matched to the factory texture.

[VISUAL PLACEHOLDER] Restoring corrosion protection: cavity wax wand inside a closed panel.
📷 Save image as: ase_b2a_corrosion_protection1.jpg  ·  prompt for labs.google.comCreate an image for an automotive refinishing training lesson. Subject: Restoring corrosion protection: cavity wax wand inside a closed panel. Style: photorealistic high-resolution photograph, automotive body shop / paint booth setting, professional lighting, shallow depth of field, sharp detail, true-to-life color, no text, no watermark. Aspect ratio 16:9.

Restore corrosion protection

ASE Surface Prep Task · A18"Restore corrosion protection to the repaired area."What it means: put back the corrosion protection repair removed, inside and out, including cavity wax in closed panels.
Key pointsRepairs remove factory corrosion protection, so it has to be restored. Cavity wax is sprayed inside closed structural panels to restore the corrosion protection that welding and repair removed.
How to Do It (Step by Step)
  1. Apply weld-through primer and seam sealer during the repair as specified.
  2. Restore corrosion-resistant coatings to the repaired exterior areas.
  3. Spray cavity wax inside closed panels and rails through access holes.
  4. Follow the vehicle maker's corrosion-protection procedure.
🎬 Video demo + narration
Film this procedure (or build a narrated slideshow from the step images). Save as ase_b2a_corrosionprot_demo.mp4 in this category's images folder, then swap this box for a <video> player.
Narration script (read in order):
  1. Apply weld-through primer and seam sealer during the repair as specified.
  2. Restore corrosion-resistant coatings to the repaired exterior areas.
  3. Spray cavity wax inside closed panels and rails through access holes.
  4. Follow the vehicle maker's corrosion-protection procedure.
📷 Step-by-step image prompts — consistent series (generate in one session; reuse the same subject/style reference so every step matches)
Step 1 — save as ase_b2a_corrosionprot_s11.jpg: Create an image showing this exact step in an automotive refinishing lesson: Apply weld-through primer and seam sealer during the repair as specified. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 2 — save as ase_b2a_corrosionprot_s21.jpg: Create an image showing this exact step in an automotive refinishing lesson: Restore corrosion-resistant coatings to the repaired exterior areas. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 3 — save as ase_b2a_corrosionprot_s31.jpg: Create an image showing this exact step in an automotive refinishing lesson: Spray cavity wax inside closed panels and rails through access holes. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 4 — save as ase_b2a_corrosionprot_s41.jpg: Create an image showing this exact step in an automotive refinishing lesson: Follow the vehicle maker's corrosion-protection procedure. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.

Remember: If repair removed the corrosion protection, you have to put it back, inside and out.

[VISUAL PLACEHOLDER] Removing a body-side molding and the leftover tape adhesive.
📷 Save image as: ase_b2a_trim_moldings_decals1.jpg  ·  prompt for labs.google.comCreate an image for an automotive refinishing training lesson. Subject: Removing a body-side molding and the leftover tape adhesive. Style: photorealistic high-resolution photograph, automotive body shop / paint booth setting, professional lighting, shallow depth of field, sharp detail, true-to-life color, no text, no watermark. Aspect ratio 16:9.

Trim, moldings, decals & pinstripes

ASE Surface Prep Task · A19"Remove and replace exterior trim, moldings, and decals necessary for proper refinishing."What it means: take trim and decals off rather than masking around them, for a clean edge and better adhesion.
Key pointsBest practice is to remove trim and moldings rather than mask over them, then remove and reapply decals, tapes, and pinstripes as needed. Removing trim gives a cleaner edge and better adhesion.
How to Do It (Step by Step)
  1. Remove moldings, emblems, and trim; gentle heat softens adhesive for clean removal.
  2. Remove leftover adhesive with an eraser wheel without scratching the panel.
  3. Refinish, then reinstall or replace trim and apply new decals/pinstripes.
🎬 Video demo + narration
Film this procedure (or build a narrated slideshow from the step images). Save as ase_b2a_trim_demo.mp4 in this category's images folder, then swap this box for a <video> player.
Narration script (read in order):
  1. Remove moldings, emblems, and trim; gentle heat softens adhesive for clean removal.
  2. Remove leftover adhesive with an eraser wheel without scratching the panel.
  3. Refinish, then reinstall or replace trim and apply new decals/pinstripes.
📷 Step-by-step image prompts — consistent series (generate in one session; reuse the same subject/style reference so every step matches)
Step 1 — save as ase_b2a_trim_s11.jpg: Create an image showing this exact step in an automotive refinishing lesson: Remove moldings, emblems, and trim; gentle heat softens adhesive for clean removal. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 2 — save as ase_b2a_trim_s21.jpg: Create an image showing this exact step in an automotive refinishing lesson: Remove leftover adhesive with an eraser wheel without scratching the panel. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.
Step 3 — save as ase_b2a_trim_s31.jpg: Create an image showing this exact step in an automotive refinishing lesson: Refinish, then reinstall or replace trim and apply new decals/pinstripes. CONSISTENT SERIES STYLE (keep identical across every step): the SAME refinish technician (same face and build, navy shop uniform), the SAME clean, brightly lit collision-repair booth, the SAME medium working camera distance and soft, even lighting. If a technician or hands appear, show correct PPE for the task. Photorealistic, true-to-life color, no text, no watermark. Aspect ratio 16:9.

Remember: Remove the trim when you can. Masking over it traps an edge and hides contamination.

Check what you learned

Masking

Which material is LEAST likely to be used as a primary barrier when masking a vehicle against overspray?

Heavy canvas tarps. Masking uses paper, plastic, tape, and liquid mask. Canvas tarps shed lint and do not seal edges.

Blend prep

What is required when preparing an adjacent panel for a basecoat blend with full clearcoat?

Remove trim and abrade edge to edge. The clear covers the whole panel, so the whole panel must be scuffed for adhesion, with trim removed for a clean edge.

Stone-chip coating

What is the proper procedure for applying textured stone-chip resistant coatings to lower rocker panels?

Follow the product maker's instructions. Chip-guard products vary; application and topcoating steps come from that product's data sheet, matched to the factory texture.

Corrosion protection

After collision repairs, what is the primary purpose of spraying cavity wax inside closed structural panels?

Restore lost corrosion protection. Welding and repair burn off and remove factory coatings inside panels; cavity wax puts that protection back.

Trim & moldings

Two techs discuss prepping around exterior moldings. Tech A says best practice is to remove the trim. Tech B says removing it gives a cleaner edge and better adhesion than masking over it. Who is right?

Both. Removing trim is the best practice and it does give a cleaner edge and better adhesion than trying to mask around it.

# Numbers & Specs for this module

Masking materials: use automotive masking paper, plastic sheeting, fine-line and masking tape, and liquid mask. Heavy canvas tarps are not a primary barrier (they shed lint and do not seal edges). Mask wide to stop overspray and soft (reverse/foam) where you blend.

Stone-chip coating: apply textured chip-resistant coating per the product maker's instructions, matched to the factory texture — not mixed into the basecoat and not over the final clear.

Corrosion protection: restore coatings on repaired areas and spray cavity wax inside closed panels after repair. Follow the vehicle maker's corrosion procedure.

🔧 Practice in the Lab

1. Mask for a blend

GoalMask a panel for a basecoat blend with full clear, using soft (reverse/foam) edges where needed.
Skill checkOverspray is contained, no hard tape ridge in the blend zone, and the adjacent panel is scuffed edge to edge.

2. Apply a stone-chip coating

GoalMask the texture line and apply chip-guard to a rocker per the product instructions, matched to the factory texture.
Skill checkTexture matches the factory look and the edge line is clean.

3. Restore corrosion protection

GoalRestore exterior corrosion coatings and spray cavity wax inside a closed panel through the access holes.
Skill checkBare/repaired metal is protected and the inside of the panel is coated.

4. Remove and reinstall trim

GoalRemove a molding with gentle heat, clean the old adhesive with an eraser wheel, then reinstall/replace it.
Skill checkTrim comes off undamaged, adhesive is removed without scratching, and it goes back on straight.

Printable Cheat Sheet

One page, the whole prep sequence and the key numbers.

[VISUAL PLACEHOLDER] Optional small step icons beside each row.
📷 Save image as: ase_b2a_cheatsheet_icons1.jpg  ·  prompt for labs.google.comCreate an image for an automotive refinishing training lesson. Subject: Optional small step icons beside each row. Style: clean modern vector infographic illustration, flat design, clearly labeled, high-contrast, white background, instructional, no watermark. Aspect ratio 16:9.

ASE B2 - A. Surface Preparation — Quick Reference

1. Inspect, Plan & Clean

Inspect & planID substrate, finish, film build (mil gauge). Over ~12 mils → strip. Write the plan.
Remove contaminantsWash, then wax & grease remover (two-rag) BEFORE sanding.
Remove corrosionDown to bright metal, then treat & prime the same day.
Final cleanBlow off → final wipe → tack, just before coating.
StaticGround the vehicle; a dry tack cloth does not discharge static.

2. Strip, Sand & Featheredge

Remove finishDA 36 to 40 grit strips all coatings; 80 shapes filler, 180 cleans up. Blast warp-prone panels; stripper = burns/fumes/runoff (no dust). Keep metal cool and flat.
SandCoarse to fine, never skip. Sand with the panel length, DA flat & light. Final P400 dry (DA) to P600 wet. Aluminum oxide general, silicon carbide wet.
FeatheredgeLevel to 150, then 180 to 220 to 320. Each layer ≥ ~1/2 inch wide; no ridge you can feel.
Block sandGuide coat + flat block; cross-block 220 wet to 320 wet, finish strokes lengthwise. Finish P400 to P600. Clean running water, never a bucket.

3. Treat, Prime & Fill

Substrate treatmentBare metal → self-etch/conversion; plastic → adhesion promoter; composite → neither.
Primer-surfacerHigh-build 2K; fills fine scratches; flash, cure, then block sand.
Glaze (finishing filler)Thin putty for pinholes/small lows after primer; sand, re-prime.
Primer-sealerSeals, even ground color, adhesion. Does NOT fill deep scratches.
Find pinholesGuide coat + block; fill, re-prime, re-block before sealing.

4. Mask, Protect & Coatings

MaskingPaper, plastic, tape, liquid mask. Mask wide; soft edges where you blend.
Blend prepRemove trim; scuff the whole adjacent panel edge to edge for clear.
Stone-chip coatingPer the product maker's instructions, matched to factory texture.
Corrosion protectionRestore coatings; cavity wax inside closed panels after repair.
Trim & decalsRemove trim when possible; eraser wheel for old adhesive; reapply decals after.
Numbers: 1 mil = 0.001 in ≈ 25 microns. Film-build limit ≈ 12 mils (strip 12–14). Featheredge layer ≥ ~1/2 inch. Coarse-to-fine grits, never skip. Verify mix ratios, flash/recoat times, and grits on the product data sheet.

Category Recap — quick review

Read the prompt, then tap to check.

[VISUAL PLACEHOLDER] Small photo strip of prep steps for a review gallery.
📷 Save image as: ase_b2a_recap_gallery1.jpg  ·  prompt for labs.google.comCreate an image for an automotive refinishing training lesson. Subject: Small photo strip of prep steps for a review gallery. Style: clean modern vector infographic illustration, flat design, clearly labeled, high-contrast, white background, instructional, no watermark. Aspect ratio 16:9.
When does wax and grease remover come, before or after sanding?
tap to reveal
Before (and clean again before coating)
Film build over about this number means strip the paint.
tap to reveal
~12 mils (strip 12–14)
Minimum width of each layer in a featheredge.
tap to reveal
About 1/2 inch
Bare steel and aluminum need this before primer.
tap to reveal
Self-etch / conversion coating
Plastic bumpers need this for paint to bond.
tap to reveal
Adhesion promoter
Tool + dust trick that finds lows and pinholes.
tap to reveal
Guide coat + block sanding
Does sealer fill deep sand scratches?
tap to reveal
No — sealer seals and evens color, it does not fill
Dust clinging to a plastic bumper is usually this.
tap to reveal
Static — ground the vehicle

Lab rubric (applies to every module's lab)

Glossary

Every key term in this category, in alphabetical order.

[VISUAL PLACEHOLDER] Optional thumbnail beside each term.
📷 Save image as: ase_b2a_glossary_thumb1.jpg  ·  prompt for labs.google.comCreate an image for an automotive refinishing training lesson. Subject: Optional thumbnail beside each term. Style: clean modern vector infographic illustration, flat design, clearly labeled, high-contrast, white background, instructional, no watermark. Aspect ratio 16:9.
A
Adhesion promoterA product that lets paint bond to hard-to-coat surfaces like raw plastic.
Abrade / scuffSanding a surface to create the mechanical "teeth" paint needs to grip.
B
BasecoatThe color layer applied over the sealer/primer, under the clear.
BlendFading new color into the existing finish so the repair is invisible.
Block sandingSanding with a firm flat block to level a surface truly flat.
C
Cavity waxCorrosion-protection wax sprayed inside closed panels after repair.
Chemical stripperA caustic product that dissolves paint off a panel; burns, fumes, runoff.
Chemical bondPaint locking to a clean, compatible surface.
Conversion coatingA treatment that prepares bare metal and resists corrosion before primer.
E
E-coatThe factory corrosion-protection layer on bare metal.
F
FeatheredgeA tapered sanded edge blending bare metal up through the paint layers.
Film buildThe total thickness of all the paint layers, measured in mils.
Finishing filler (glaze)Thin putty for pinholes and small lows after primer.
G
GritThe coarseness of sandpaper; lower number = coarser, higher = finer.
Guide coatA light contrasting coat that reveals highs, lows, and pinholes when block sanded.
M
MaskingCovering areas you are not refinishing with paper, plastic, tape, or liquid mask.
Mechanical bondPaint gripping the tiny teeth left by sanding/scuffing.
Mil / mil gaugeA unit of thickness (0.001 in ≈ 25 microns) and the tool that measures film build.
P
PinholeA tiny hole in primer or filler that must be filled before paint.
Primer-sealerAn undercoat that seals, evens the ground color, and improves adhesion (does not fill).
Primer-surfacerA high-build undercoat that fills fine scratches and is block sanded flat.
S
SealerSee primer-sealer; locks down the surface before basecoat.
Self-etching primerA primer that chemically bites into bare metal and resists corrosion.
Static electricityA surface charge that pulls dust to the panel; discharged by grounding.
Stone-chip coatingTextured chip-resistant coating for rockers and lower panels.
SubstrateThe surface being prepped: steel, aluminum, galvanized, plastic, composite, or old paint.
T
Tack clothA sticky cloth that lifts dust and lint just before coating.
Two-rag methodApplying cleaner with one rag and wiping with a clean dry rag before it flashes.
W
Wax and grease removerA solvent cleaner used before sanding to remove contamination that ruins adhesion.

Practice & Assessment

Everything to learn this lesson, practice it, and get checked off in the lab. Start with the Pre-test, finish with the Skills Evaluation.

📝 Pre & Post Test
Take it before and after. See how much you gained.
🃏 Key Terms Practice
Flashcards, match, and quiz the prep terms.
🛠 Tools & Equipment ID
Know your tools, then test yourself.
✅ Student Skills Sheet
See exactly what you'll be graded on in the lab. Self-check first.
📋 Lab Skills Evaluation INSTRUCTOR
Digital, paperless grader — tasks plus each PPE piece, posts to the student's account.

Now test yourself

You know the prep sequence. Drill it in the simulator: timed section exams, hundreds of B2-A questions, and instant feedback.

[VISUAL PLACEHOLDER] Screenshot of the asecollisiontestprep.com B2-A section dashboard.
📷 Save image as: ase_b2a_simulator1.jpg  ·  prompt for labs.google.comCreate an image for an automotive refinishing training lesson. Subject: Screenshot of the asecollisiontestprep.com B2-A section dashboard. Style: clean modern vector infographic illustration, flat design, clearly labeled, high-contrast, white background, instructional, no watermark. Aspect ratio 16:9.
Open the B2-A Simulator →
All QuestionsDirectTech A/BEXCEPTMost LikelyLeast Likely

[LINK PLACEHOLDER] Point this button to the B2-A section of asecollisiontestprep.com.

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ASE B-Series Academy · ASE B2 - A. Surface Preparation
Written in plain language for students ages 18 to 60. Always follow the paint maker's product data sheet for grits, mix ratios, flash times, and film thickness.