Painting Galvanized Sheet Metal

[letterman]

I bought a used trailer with a homemade box on it. The walls are plywood, the roof is galvanized sheet metal. The galv. roof was bare for at least 5 years, so the metal had plenty of weathering to remove the oils that are on new galvanized metal. Last summer I painted the whole trailer with Rustoleum brand oil based paint made for metal. I brushed it on, and gave it two coats. The paint on the wooden sides has held up well, but over winter the paint almost completely came off the galvanized metal roof. It actually peeled off in large sheets. Apparently the contraction of the metal caused it to come loose.

Is there any way to paint galvanized metal?

[gpsman]

http://164.109.30.55/howto/problems_details.aspx?problem=poor_galvanized_metal_adhesion -----

- gpsman

[Jim Elbrecht]

Note that they make a 'rusty metal primer' a 'clean metal primer' and a 'galvanized metal primer'.

No, IMO, 'apparently' the primer didn't bind to the galvanized.

Yep. Read the product literature. Rustoleum has been sticking paint to metal longer than any of the others that I can recall.

Jim

[gfretwell]

If you go to an auto paint store they can sell you an etching primer that will eat through the oxides on galvanized metal or aluminum. It is nasty stuff and you need a respirator but it will get the job done. This is what I used on my aluminum boat and it has lasted 13 years in salt water.