How to Paint an Auto Using a Clear Coat

The application of clear coat lacquer over a base color will produce a high-gloss shine that is hard, durable and resistant to ultraviolet light. There are many different types of clear coat, but the automotive industry tends to favor acrylic or urethane-based materials because of faster drying times and ease of use. Solvent-based clear coats release harmful vapors including polyisocyanates so it is equally as important to use the correct safety equipment as it is to use the right application techniques.

Instructions

1

Read through the technical data sheet supplied with the clear coat before work begins and establish the correct mixing ratio and spraying temperatures. Turn the paint booth on to spray mode and adjust the temperature setting dial until it complies with the technical data sheet. Usually, a spraying temperature of 20 degrees Celsius is ideal. Activate the clear coat in a mixing pot using a measuring stick which clearly outlines the correct mixing ratio. Add hardener and thinners and stir thoroughly before adding the material to an HVLP spray gun.

2

Apply panel wipe to a lint-free cloth and wipe thoroughly over the surface to be painted. Dry off with a clean piece of cloth and run a tack rag over the surface to remove any last traces of hair, grit or cloth fibers. Put on an air-fed respirator as a means of protecting yourself against harmful vapors, and wear a pair of latex gloves to stop overspray landing on exposed skin.

3

Set the air pressure regulator to 29 psi and hold the gun approximately 4 to 6 inches from the face of the painting surface. Start to the side of the surface and pull back the trigger of the gun. Apply a closed coat of clear coat at medium volume to seal in the base color. Move your arm in a sweeping motion using a consistent speed and ensure that effective cross-coating takes place so there are no dry patches in your clear coat.

4

Leave the first coat to flash off for 3 to 5 minutes. Check the masking paper surrounding the working surface to see if the first coat has become tacky before continuing. Apply the second coat as a full covering at high volume. Slow down your arm movements slightly in comparison to the first coat to guarantee a full application but maintain consistent movement to prevent sags or runs. Carry out a visual check once the second coat has been applied to ensure the clear coat is evenly distributed and free of dry patches.

5

Leave the clear coat to cure for 5 minutes before turning the paint booth onto bake mode. Bake the clear coat in accordance with the technical data sheet. Baking times will vary based on the type of thinner used when mixing. Clean the HVLP spray gun in a gun cleaning machine that uses cellulose thinners and ensure all unused clear coat is placed into a suitable receptacle that only holds waste solvent-based products.