Patio chairs that were sandblasted, zinc-primed and powder coated about one year ago have started to rust in the area where the expanded metal seat fits into the formed frame. What went wrong in the original process, and how can we fix this problem?
Should type 316 stainless steel castings be sandblasted before powder coating, or can they be chemically etched? Should the parts be pre-heated in an oven before coating?