Galvanized Steel Edge Treatment

Question:

I am the manager of manufacturing at our plant. Our plant produces stampings from hot-dipped galvanized material. These parts are being shipped overseas and will be E-coated at a later date. Naturally, the raw edges of cutouts and other edges are rusting due to the corrosive atmosphere encountered during overseas shipment. Our customer has to remove the rust before final coating. We are searching for an inexpensive coating/treatment to protect the edges from corrosion in transit. Any suggestions ? R. W.

Answer:

There are several approaches you can take to protect the raw edges of galvanized steel from corrosion. Among these are rust-preventatives, paints and strippable coatings. Most of these treatments must be removed before the parts are E-coated. Suppliers of rust-preventatives are listed under Rust-Preventative Chemicals and Oils in the suppliers database. Probably the easiest to remove are the strippable coatings. The trick is finding one with sufficient corrosion resistance for your application. I just read an article in the April 2005 issue of AIR FORCE magazine about moth-balled aircraft stored in the Arizona desert. They were protected from wind and rain by a strippable coating. While it is true that the desert atmosphere exposure is not as corrosive as that in a shipboard container on the open seas, it is also true that the lengths of exposure are different. Suppliers of strippable coatings are listed under Spray Booth Coatings in the suppliers database.