Sound technical content, curated with aloha by
Ted Mooney, P.E. RET
Pine Beach, NJ
The authoritative public forum
for Metal Finishing since 1989
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Wet Coat Paint or Powder coating onto Zinc/yellow chromate finish
Q. We are a small company in New Dundee Ontario - and we are experiencing bondage problems and thought you may be able to help. We manufacture CRS racks for military applications. Our customer has requested that we Zinc plate with Yellow Chromate for paint adhesion. Then Vinyl wash primer and yellow zinc dust
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, wet coat baking enamel. On small test samples we appears to achieve proper bondage. However, on actual racks, we loose bondage around bolt holes and pressure points."
STOP!
At this point, you need to see if this coating system is reasonable. Ask to see the military specification or some other basis for this coating system. It can't be a list of mil specs for each individual coating, it must be for the system. Your vendors of coatings can help, but you have to work from the top coat backwards to the primer, then wash, then chromate. Unless you formulate your own paint, you can get a recommendation for compatible bottom coats.
Tom Pullizzi
Falls Township, Pennsylvania
1999
