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White Rust on Galvanneal
We use a 12 ga tube that is galvannealed for a product that is powder coated. We have noticed what appears to be (white rust) or zinc chloride that precipitates to the surface of the tube which creates problems in our powder coating process. If the tube is not cleaned using Scotch Brite [affil. link to info/product on Amazon] before being prepped and painted the paint has a tendency to develop crater or pits in the surface. This material may be in our inventory for 90-120 days before processing. The material is stored inside our plant.
Are we experiencing moisture problems or are we experiencing some other type reaction.
- Atlanta, Georgia, USA
The tendency to form white rust on galvanized products is prevented by the means of chromating process. This is a post process to galvanizing.Rajan Surve
- Kennesaw, Georgia, USA
Whoa! There are definitely other alternatives to chromate. If you did not receive it in this condition you might have a storage problem. You can get some great free information from the American Galvanizers Association on their website www.galvanizeit.org. There is a manual called "Wet Storage Stain." It will be very helpful.M Stroia
Gregory Industries - Canton, Ohio, USA