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Sat Jul 12, 2008 8:27 am

I'm just wondering what primer is best for galvanized metal - self-etching? Red oxide? Standard grey?

Sat Jul 12, 2008 7:35 pm

Wash with 50% vinegar/water,rinse well,dry well[hair dryer]and paint with the old reliable; Rustoleum Rusty Metal Primer. Top coat with whatever you have.

Sat Jul 12, 2008 8:17 pm

You wouldn't want to use self etching primer on zinc galvanized metal, it would not be compatible. Zinc coating is pretty much the gold standard of metal protection. All you need to do now is provide a good substrate for the color coats. I'd just use a good epoxy or 2K urethane primer. You'll want to sand/scuff the galvanized surface slightly to promote good primer adhesion. Most people use 80 grit sandpaper on bare metal, but you need to remember that zinc is a fairly soft metal and you don't want to go through the zinc and expose the steel underneath. Maybe use 120 grit (or even higher) or a medium scotchbrite pad. Don't over do it on the sanding. You just want a slight scuff.

Definitely stay away from red oxide or gray lacquer based primers (which is what pretty much what all rattle can primers are). This is basically 1950's paint technology (if not older), and it is generally not compatible with modern paint packages and they do not offer the adhesion or protection of modern primers.

Visit your local automotive paint jobber. They can give you information and will carry the epoxy or 2k urethane primers you will probably want to use. If you know what paint you plan to use for your color coat the paint jobber will be able to direct you to the particular primers which are made to be compatible with your chosen paint.

If you don't have a jobber nearby Eastwood's has some decent primers and paints. Visit http://www.eastwoodco.com/index.jsp . They also have a forum where you can ask some of the Eastwood people questions about their products (see http://forum.eastwoodco.com/ and go to the "Ask Eastwood" forum).

Sat Jul 12, 2008 8:30 pm

BTW, I don't think I would use Rustoleum Rusty Metal Primer on top of galvanized steel of any sort. You are after all priming a zinc surface, not rusty steel. Most of these rusty metal primers are a conversion coating. They converter iron oxide to typically iron phosphate or some similar inert surface. They are made to be used on rusted surfaces and most in fact warn against using them even on clean bare steel. However, don't trust me on this, check the application information on the product which you should be able to find at Rustoleum's website.

Sun Jul 13, 2008 2:53 am

Cool - gets me a little more insight... I was just wondering for low-level paint stuff - not even necessarily automotive. So nothing that would get epoxy/2K products.

I did just weld a few tiny pieces of galvy onto some engine tin to plug some holes, and wonder how my primer will hold. I think I did use self-etching, then just rattle can. Oh well, live and learn.

Sun Jul 13, 2008 4:14 am

https://buyat.ppg.com/refinishProductCatalog/Serve...42d74727ca

etch primer is designed to be applied over galvanize steel. Do not put it over filler.

All cars made it the past 15 years have a galvanize coatin on them. The factory uses some sort of etch primer on all of them.

https://buyat.ppg.com/refinishProductCatalog/Serve...adedcd79ca

DO NOT PUT EPOXY OVER GALVANIZED METAL, It will NOT stick

Sun Jul 13, 2008 10:25 am

I stand corrected. Working on classic cars doesn't give me a lot of opportunity to see much galvanized metal. Reading the information from the previous poster it looks like self etching primer would be the way to go. As stated before though, stay away from lacquer based gray or red oxide primers and remember that most rust conversion primers are meant to be applied over a rusted surface and don't always do well on clean metal.

Sun Jul 13, 2008 11:40 am

Go visit your local Home Depot. They carry primers in aerosol cans specific for Galvanized metals

Mon Jul 14, 2008 12:58 pm

Yea; I'm a housepainter and I know all the rules for wood/cement/plastic but metal is a different beast. So I also know all the levels of adhesion/protection that can be with paint.

So gray primers are lacquer-based? I'm curious now - I sprayed my tins with Duplicolor acrylic-lacquer just 'cause it was the only semi-gloss black they had at my FLAPS. We'll see how it does.

And I painted my generator stand black (it allready had white and black paint on it) but I want it gray now... so what will go over acrylic-lacquer? Should I prime it first? I might just wing it. No time to sandblast it...