Cost of powder coating zinc vs aluminum die castings

What is the cost comparison between powder coating Aluminum die casting products and zinc die castings?

Emad,

Powder coating either casting should be similar in price. We only powder coat zinc castings now, but we used to use the same line to powder coat both metals. If memory serves the only difference was the pretreatment process. Specifically the addition of a small amount of fluoride to the iron phosphate bath. I believe this was used as an adhesion promoter/etchant for the Al. This added a little bit of extra cost for the fluoride additive and an extra analytical procedure. Although I will say (in my case) the scrap rate was a bit lower on the Al. The Zn castings I was working with seemed more prone to outgassing and porosity.

Good Luck