49049

Pretreatment discoloration [India]

June 16, 2008

We are doing tricationic pretreatment on screws / fasteners /jobs and doing zinc silicate primer and epoxy acrylate topcoat baking finish on that.

jobs becomes yellowish / redish after keeping standard
conditions for pretreatment, while regular test panels shows good pretreatment pattern. whether it is due to
hardening process done before pretreatment please explain.

Shirish Vartak
coatings - Pune, Maharashtra, India