Paint Repair - Basic Topcoat Application Process
1. Basic Topcoat Application Process
Use of 2K Paint (Example)
1.
Light Coating:
Spray a light coat to check for any issues with the paint.
When lifting is found on the surface of coating, fill with dry coating.
2.
Fixing Color:
Spray a medium coat.
Continue spraying until the basecoat is completely covered.
Do not attempt to spray one thick coat. Apply several thin coats with sufficient flash time in between.
For metallic colors, spray carefully not to create color unevenness. Pay attention to overlap pattern.
3.
Removing Unevenness (Metallic Color, Pearl Color):
Maintain the same spray size as the color fixing process and hold the gun slightly further away from the coating surface. Move the gun more slowly to leave the surface a little wetter.
By keeping the surface a little wet with paint, it is possible to let metallic and pearl base arrange regularity, which reduce any uneven surface appearance.
Overlap spray gun passes repeatedly until the paint film surface evens out.
4.
Finishing:
1-Coat Solid
Finish the coated surface smoothly and match the adjoining panels’ surface quality.
Metallic, Pearl and 2-Coat Solid
Spray clearcoat to smoothly finish the coated surface.
States of Finishing Surface and Coating Conditions (Reference)
Surface coating method
Type of Surface
Roughness of Surface
Fine surface
Rough surface
High
Low
Spray Gun Nozzle Diameter
Small
Large
Large
Small
Paint Viscosity
Low
High
High
Low
Spray Pressure
High
Low
Low
High
Distance of Spray Gun
?
?
Far
Near
Speed of Spray Gun
Fast
Low
Low
Fast
Thinner Evaporation Speed
Fast
Low
Fast
Low
Flash Time
?
?
Required
Not Required




Flash Time and Set-Up Time

Flash Time (Interval between Paint coats)
When layering several coatings, allow paint solvent to evaporate somewhat before applying another coat. This waiting time between the paint coats is called flash time.

Set-Up Time
The time between completion of painting and starting of the force-drying process. If the painted surface is heated immediately after application where the solvent is still very actively evaporating, paint defects such as pinholes will occur.
Steps of Gradation Paint (Gradation of Solid and Clear)

NOTE: Gradation paint is a clear paint diluted by the paint reducer/thinner. Its viscosity is very low and it applies in very thin layers.
1.
Spray so that the luster will be even with the old painted surfaces.
2.
Dilute the finishing paint following the paint manufacturer’s instructions.
3.
Spray the gradation paint so that the new and old surfaces blend with each other.
Steps of Gradation Paint (Gradation of Metallic and Pearl)

NOTE: Gradation paint is a clear paint diluted by the paint reducer/thinner. Its viscosity is very low and it applies in very thin layers.

When using under clear coating
1.
Spray under clearcoating roughly around the repair area.
2.
Spray a base color on the under cleared area.
3.
Repeat these steps until no differences between the old and new paint layer in color while keeping the under clear wet.