ASE Painting & Refinishing 2 — Questions and Answers
Question 1: What is the primary purpose of applying a primer-surfacer before basecoat?
- To add gloss to the final finish
- To fill minor imperfections and provide a sandable, uniform surface (Correct answer)
- To speed up the drying of the clearcoat
- To increase the metallic flake orientation
Correct answer: To fill minor imperfections and provide a sandable, uniform surface
Primer-surfacer fills small scratches and sand marks and can be sanded smooth to level the surface before color.
Question 2: A solvent that evaporates too quickly in hot conditions most commonly causes which defect?
- Runs and sags
- Dry spray or poor flow (Correct answer)
- Fish eyes
- Wrinkling
Correct answer: Dry spray or poor flow
A reducer that flashes too fast prevents the paint from flowing out, leaving a rough, dry-spray texture.
Question 3: What does the term 'flash time' refer to in refinishing?
- The time the spray gun trigger is pulled
- The interval allowing solvents to evaporate between coats (Correct answer)
- The time a panel spends in the bake cycle
- The exposure time of UV-cured primer
Correct answer: The interval allowing solvents to evaporate between coats
Flash time is the period between coats that lets solvents escape before the next coat is applied.
Question 4: Fish eyes in a fresh paint film are typically caused by what contaminant?
- Excess hardener
- Silicone, oil, or wax on the surface (Correct answer)
- Too much reducer
- Low booth temperature
Correct answer: Silicone, oil, or wax on the surface
Silicone and oily contamination repels paint, creating crater-like fish eyes.
Question 5: When color-matching, what is the purpose of spraying a 'let-down' or test panel?
- To check primer adhesion
- To verify the color match and metallic appearance before painting the vehicle (Correct answer)
- To measure dry film thickness
- To test gun pressure only
Correct answer: To verify the color match and metallic appearance before painting the vehicle
A spray-out/let-down panel confirms the blended color matches before committing to the actual repair.
Question 6: Which spray technique helps avoid mottling in metallic basecoats?
- Heavy wet coats applied close to the panel
- Consistent gun distance with proper overlap and adequate flash between coats (Correct answer)
- Increasing reducer beyond recommended ratio
- Spraying with no overlap
Correct answer: Consistent gun distance with proper overlap and adequate flash between coats
Even gun distance, correct overlap, and proper flash let the metallic flakes lay uniformly.
Question 7: What is the function of a hardener (activator) in a two-component (2K) coating?
- To thin the paint for spraying
- To chemically cross-link the resin so the film cures (Correct answer)
- To add color tint
- To slow flash time only
Correct answer: To chemically cross-link the resin so the film cures
The hardener triggers the chemical cross-linking reaction that cures 2K paints to a durable film.
ASE Painting & Refinishing 2
What is the primary purpose of applying a primer-surfacer before basecoat?