Ask the Expert Question-and-Answer Archive

by Ron Joseph

October, 2004

Adhesion over Hot Dip Galvanized Steel

Q. I heard that when you apply paint on GI ( Hot Dip galvanise steel ) it sometimes tends to detach or peel off? Is it true for Cold Galvanizing paints on Hot Dip bare GI.

Painting over galvanized steel is often questionable. If you apply the cold galvanizing paint over the hot dip galvanized steel, make absolutely sure that you have properly prepared the surfaces and that you have removed any zinc oxide corrosion products that might be present on the substrate. An epoxy zinc-rich primer (cold galvanizing) should perform very well.

Ron Joseph