Touching Up Powder Coating with Liquid Paint
Our company out sources powder coating on several parts for the aerospace industry. On several occasions we have had need to touch up areas of the powder coat. Like every other business, we like to minimize time required to rework these problems and perform the operations in house. We have several excellent painting/dry film coating operators in house. The problem has been in how can we touch-up the powder coat with a liquid paint? We are not in the business of powder coating and thus do not have a good understanding of powder coating. I have read one article regarding stripping powder coats on this web site that mentions liquid touch-up, but it doesn’t tell me, a real novice, enough to develop a process for touch-up. If you could help by explaining which liquid paints are useful in powder coat touch-up and surface preparation required for liquid paint application on various powder coatings, I would greatly appreciate it? D. W.
There are several basic steps that you need to take before you begin to touch-up on a powder coated product. First you need to talk to the powder coating formulator (the guy who supplies the powder coating, not the guy who does the powder coating) to ask what is the appropriate liquid paint formulation that will work with their powder coating. Some liquid touch-up paints can cause incompatibility problems with the powder coating and you will end up with a real mess. Knowing which paint to use is half the battle.
Second you need to evaluate if the touch-up area needs further preparation. For instance, does the affected area need to be sanded to feather and edge? Does the area need to be sanded to scuff the surface for good liquid touch-up paint bond? Are there some mechanical preparation steps that need to take place (i.e. filling scratches, pulling dents, removing rust, etc.)?
Lastly, clean the affected area after all sanding and mechanical work has been performed. Cleaning methods can be simply wiping the affected area with solvent and a clean rag. Then apply a complete and even coat of the touch-up paint. Use multiple coats if necessary. If your painters are as good as you say they are, they should have no problem with this.