Paint Materials, Mixing, and Color Matching
What this domain tests
Paint systems, mixing ratios, pot life, viscosity, reducers and hardeners, colour theory, variant selection, and blending.
Core rules
- Read the technical data sheet for every product. Mix by volume unless the sheet says by weight; ratio errors cause soft films, poor gloss, or no cure.
- Use the specified hardener and reducer for the temperature. Too fast a reducer in heat causes dry spray; too slow in cold causes runs and solvent pop.
- Respect pot life. Catalysed 2K material that has gelled must be discarded; adding thinner does not revive it.
- Stir metallic and pearl basecoats gently but thoroughly. Pigment settles, and over-stirring can drive metallics to the surface.
- Match colour with a variant chip or spray-out card under the correct light, then confirm in daylight and under shop lighting. Metallics change with angle and application.
- Blend into adjacent panels rather than trying to match panel-to-panel on a metallic.
Worked example
Mix a 2K primer at 4:1 by volume, with 10% thinner based on the paint-plus-hardener volume. You need 200 mL of paint. Reasoning: hardener equals 200 divided by 4, which is 50 mL. Paint plus hardener equals 250 mL. Thinner is 10% of 250, which is 25 mL. Total is 275 mL. Check pot life, for example 45 minutes, and mix only what you can use. If the sheet says thinner is based on paint only, the thinner would be 20 mL, so the sheet governs.
Traps
- Measuring by weight when the ratio is volumetric.
- Adding extra hardener to speed cure; it makes a brittle, less durable film.
- Using a close-enough reducer that is not compatible with the system.
- Judging metallic colour under one light source.