painted galvanised metal without primer

[diyhack]

Hi all, i have a roof strucutre that wasnt primed / undercoated incorrectly and all the paint is flaking off the Galvanised metal. Not sure what to do as it will be a huge job to grind off all residual paint. Is there some paint product i can reapply over the top or do i need to strip everything back to bare metal and start again?

[Brad]

Hate to be the bearer of bad news but not much will stick to flaking paint.

Scrape the loose stuff off first.

Then choose either a paint stripper or wire brush both are evil but with what looks like nearby water the wire brush maybe least evil. Safety gear is a must and I know from experience pulling wire out is not a fun thing.

If you can find solid paint you can leave it on, feather the edges with sandpaper if it looks too thick to blend in nicely.

Prime, most would say clean and prime in the same day looks like you may have to break it into areas or make it a team effort.

Top coats.

[Andy_Mann · Accepted solution]

@diyhack from your photo, the rust seems fairly minor, here are some links from the White Night's Rust Guard line:

Rust Converter

Metal Primer

Epoxy Enamel

On the Rust Converter page, click the How To Apply tab above the photo, for a brief guide.

Late note: Sorry guys, I didn't know Brad had posted until after I'd submitted.

[MartyH]

Yep, you need to get the paint off @diyhack. A wire brush should do the trick. 

When it comes to priming and repainting, you might want to try the spray cans - can be quick and easy.