CAADE Repair and Refinishing Processes 2 — Questions and Answers
Question 1: Which welding process is most commonly recommended for joining high-strength steel (HSS) panels in modern vehicle repair?
- Oxy-acetylene welding
- MIG (GMAW) welding (Correct answer)
- TIG (GTAW) welding
- Spot welding with indirect current
Correct answer: MIG (GMAW) welding
MIG welding is the industry standard for HSS repairs because it produces less heat distortion and maintains panel strength.
Question 2: When performing a blend repair on a metallic base coat, the blending solvent is applied to:
- The repaired panel before base coat application
- The adjacent panel edge after base coat application (Correct answer)
- The clear coat layer before buffing
- The primer surface before sanding
Correct answer: The adjacent panel edge after base coat application
Blending solvent is applied to the feathered edge of the adjacent panel after base coat to soften and melt in the new color.
Question 3: What is the primary purpose of a seam sealer in structural repairs?
- To add decorative trim lines
- To prevent corrosion and moisture intrusion at panel joints (Correct answer)
- To improve paint adhesion on bare metal
- To fill minor surface scratches before priming
Correct answer: To prevent corrosion and moisture intrusion at panel joints
Seam sealer prevents water, air, and contaminants from entering panel joints, protecting against rust and structural degradation.
Question 4: When estimating the cost of refinishing a door jamb during a full door replacement, the estimator should:
- Always include jamb refinishing as a separate line item (Correct answer)
- Include it only if the customer specifically requests it
- Exclude it as it is always part of the door panel time
- Include it as an included operation with no additional charge
Correct answer: Always include jamb refinishing as a separate line item
Door jamb refinishing is typically a separate, billable operation because it requires masking and additional labor beyond the outer panel.
Question 5: Which surface preparation step is critical before applying a two-stage urethane primer-surfacer?
- Waxing the surface to improve adhesion
- Scuffing or sanding to create mechanical adhesion (Correct answer)
- Heating the substrate to 200°F
- Applying a waterborne sealer first
Correct answer: Scuffing or sanding to create mechanical adhesion
Scuffing or sanding creates a mechanical profile that allows the primer-surfacer to bond properly to the substrate.
Question 6: Ultra-high-strength steel (UHSS) structural components are typically replaced rather than repaired because:
- They are too expensive to repair
- Heat from welding or reshaping destroys their metallurgical properties (Correct answer)
- Insurance companies will not pay for repairs
- Replacement parts are always cheaper than labor
Correct answer: Heat from welding or reshaping destroys their metallurgical properties
UHSS is engineered to precise metallurgical specifications; heat from repairs alters the grain structure and eliminates its designed strength.
Question 7: A technician notices fish-eye defects appearing in the freshly sprayed base coat. The most likely cause is:
- Too much reducer in the mix
- Silicone contamination on the substrate (Correct answer)
- Insufficient flash time between coats
- Incorrect gun pressure
Correct answer: Silicone contamination on the substrate
Silicone contamination from polish or wax repels paint, causing the circular fish-eye craters in the finish.
CAADE Repair and Refinishing Processes 2
Which welding process is most commonly recommended for joining high-strength steel (HSS) panels in modern vehicle repair?