Drip coating is an important skill that every auto body paint sprayer should aspire to master. Drop coats are delivered during the last phase of the spraying process when using metallic paints. When properly applied to a body panel, the reduced coats offer full color coverage, perfect distribution of metal content, and a better paint base that can easily accept lacquers.
Apply metallic paint
Drip coating should be used with all metallic automotive paints. Many paint sprayers apply metallic basecoats using the same methods as they apply solid colors, and this is a common mistake that compromises an otherwise perfect job. While horizontal arm motions are perfect for most solid color spray jobs, metallic car body paint should be dropped onto the panel as soon as basic coverage has been achieved, and it is equally important to apply a cross coat in final application in horizontal and vertical directions.
Ensure uniform paint coverage
Before drop coats can be applied, the prepared car panel must be adequately covered with metallic body paint to help prevent primer transparency. Once the color is activated, a full coat of wet paint should be sprayed on the panel surface. It is essential that each horizontal spray movement mixes with the previous one to ensure even coverage and distribution (overlaps of 30% to 40% are perfect). As soon as a single coat of we has been applied, the body paint should be allowed to dry for about 10 minutes. Never spray a second coat until the first has achieved a matte look.
Apply a second coat of metallic paint
Personally, I like to spray the next coat of paint in a different direction than the first, especially when the car panel has been removed. Sometimes this is not possible on vertical panels, such as the fenders and doors, if they are still installed on the vehicle, so don’t worry too much if you are happier using a typical horizontal spray pattern. The second application should be sprayed similarly to the first, but try to achieve 80% humidity compared to the previous application. Again, the body paint should be allowed to dry for about 10 minutes until it is matte.
Application of the protective layer
If the metallic paint is still clear, an additional coat may be required, but this will not be necessary in most cases. To spray the actual protective coating, position the spray gun 18-24 inches from the panel surface and reduce the gun pressure by 20-30%. Spray the body paint horizontally, moving your arm slowly across the panel so that the metallic color falls (or falls) onto the surface. Maintain even coverage until spraying process is complete. Coat the panel from a similar distance right away, but swap the horizontal strokes for a vertical direction so that the back coat crosses the first. In addition to ensuring uniform paint coverage, crossing the protective layer offers an even metal distribution and a superior surface that will accept the lacquer correctly.
Crossing out the coat
Allow the protective coating to dry before visually inspecting the metallic body paint. Look for patches where coverage may be inconsistent and spray an additional coat if necessary. With solvent-based body paint, it’s always a good idea to wipe an adhesive cloth over the vehicle’s dashboard as soon as the protective coating has dried. Specialized water-based car paint tack rags can be purchased, but it is preferable to skip the adhesion process as a high build-up of paint can strip the color and this can lead to frustrating rework.