How to Paint Over Galvanized Steel?

Old 10-02-23, 04:28 AM
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How to Paint Over Galvanized Steel?

I have a galvanized chimney chase made of galvanized sheet metal.

You'll notice that, after 39 years of service, portions are showing some rust, which I'd like to clean off and paint over for protection from further rusting.

Everywhere I look on the web, I see statements like "do not apply alkyds" to galvanized steel. However, I'm finding it difficult to find a latex primer for galvanized steel. Tremclad has this primer that supposedly works for galvanized, but it is oil-based.

Can anyone clarify what I should be using to prime this?



Old 10-02-23, 05:05 AM
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I'd use an oil base primer over just the rusty areas and then finish with latex.

Thin sheet metal flexes too much and oil base coatings can pop off of it, latex is a little bit flexable.
Old 10-02-23, 05:59 AM
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From what I have learned, you don't use oil based on galvanized because it reacts with the zinc and can peel. But i know Marksr has probably painted miles of it. But you can use latex primer on weathered galvanized. It's passivator that causes latex paint to fail, and it's typically only present on new galvanized.

See this thread: Painting galvanized metal

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