powder coating. how well do you know your powder coater? the company I work for runs the wash system for 2 years without changing the water and phosphate an now the second chemical wash stage doesn't work at all and we are out of phosphate solution, but we continue to run. the chemicals we use should not be used on aluminum,stainless, or galvcoat. when we did aluminum tool cases this week they came out spotted and if you cut a line you could peel it off like tape. if you take anything to a powder coater have it sandblasted and ready because most of the time they won't take time to prep it right. time is money to them. try picklex at home on your parts an coat them yourself. good luck an keep up the great site.