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Parts must be painted, so what galvanized steel to spec?

2003

I need to paint over either Galvanized steel or Galvannealed Steel, to conform to UL ASTM ASTM B117, what galvanized steel is the best to use for this application. We are having a flaking problem on Galvanized steel (16G). Material is cut and formed.

Any help would be appreciated.

Klaus Reitter
Quality Engineer - Moorpark, CALIFORNIA, USA

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Galvanneal or galvalume are better to paint than galvanize. In addition chromate conversion coating is helpful

Don Baudrand
Consultant - Poulsbo, Washington
(Don is co-author of "Plating on Plastics" [on Amazon or AbeBooks affil links]
           and "Plating ABS Plastics" [on Amazon or eBay or AbeBooks affil links])
2003

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First of two simultaneous responses --

Hold the chromate, please. I think you want your substrate chromate free or chemtreat free, for anything that needs painted. Galvanneal is made to paint. Flaking could be from anything, but it is probably surface preparation.

Mike Stroia
Galvanizing - Canton, Ohio, USA
2003

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Second of two simultaneous responses --

If high temperature hot dip galvanize is applicable it could be of some help. Slight sand-blasting is essential for duplex-coating. There is a German standard for duplex.

Dr. Norbert Seyfert
surface development - Olpe, Germany
2003