I ve powdercoated clear some alu parts I had polished.
I ve used a 100 $ Eastwood gun and Gloss Clear Eastwood powder.
After polishing the parts, I have used Autosol (same as Mirror in Europe) to have a quite perfect appearance, then washed with lacquer thinner, Simple Green and Acetone.
The first parts I powder coated had really too much powder. So it s thick. Much more than necessary.
So it s supposed to be air proof.
Since, the parts have been stored on a shelve inside. It s been about 2 years.
And ALL the alu parts seems to have oxidation under the coat. Funny when you can imagine how many hours I spend polishing …
See the pix as sample. The parts I have are not all made of the same alloy.