Powder Coating Aluminum

Question:

Even if you don’t know, please let me know where I can find a solution to this problem. I am attempting to use powder coating for the instrument panel of an aircraft. The aluminum is 0.032 inch thick. One of the questions regarding this is a note in Part 43, which says, “2024 aluminum should not be heated above 212F, because the heat will reduce the strength of the heat-treated aluminum.” If the strength is reduced, how much is it reduced during the curing of a part that has been powder coated?If the strength is reduced, how much thicker sheet of aluminum is needed (whose strength is also degraded by the heating process) after powder coating?Is it possible to get the strength back by any other process that will not destroy the powder coating?Thanks in advance. G. V.

Answer:

Not being a metallurgist, I would not even guess the amount of strength reduction that occurs in 2024 aluminum parts when exposed to powder curing temperatures that start at 250F and go to 400F. My recommendation is that you do not even try to use a heat-cured coating (like powder coating) on this part. There are many air-dried liquid coatings and two-part catalyzed liquid coatings that can be used on this surface to provide great service life. Let’s face it—an aircraft instrument panel does not see a very corrosive environment that demands the high performance of powder coatings. Why risk degrading the component to apply a high-performance powder coating, especially in an aircraft? There are some things where the performance of powder coatings is not justified, especially if the process degrades the strength of the part.