Peeling Paint: How to Get Paint to Adhere to Steel Siding

LESLIE: Rich in Illinois needs some help with getting paint to adhere to steel siding. Tell us what you’re working on.

RICH: I’m working on a house that I’ve been living in since 1988. And the bottom four sections of my steel siding keep peeling. It’s like a 30-foot-long piece. Each piece is 8 inches wide. And it has a wood-grain pattern on it; looks like it’s been stamped. And every two years, I approach this project. First time, I took a wire brush to it and knocked all the loose off and primed it. And two years later, I was doing it again.

And every year, I try a different method to get paint to adhere to steel siding. I tried a wire wheel on a drill. Last year, I took an air compressor and a hose and a drill and a wire wheel and went down to the bare metal.

TOM: Wow.

RICH: And went to the paint store and they gave me some primer and some paint. And seemed like everything I try – I wash it with paint thinner sometimes before I do it. Sometimes I just use soap and water. I always make sure it’s a nice, dry day – about 80 degrees – when I paint it. And it seems to always come back about every two to three years.

I know it should be replaced but I kind of like the siding. But it’s steel and it’s – the company is no longer in business now and so the warranty is up on it.

TOM: And there’s different qualities of steel. So even if it had a rust-resistant finish on it, it could have just worn off. And I wonder if whatever process they used is what’s causing the problem of getting paint to adhere to steel siding.

When you prime it, are you using an oil-based primer or are you using an alkyd primer?

RICH: Both. I’ve used both. I don’t know if it’s the primer that I use or if it’s – I’ve even went down to no paint at all and just the galvanized showing and – I don’t know. I don’t know what it – I don’t know if it’s the primer or what I’m using to wash the siding with that’s causing it or it’s the paint. I tried four or five different kinds of paint on this and primer.

TOM: What I would do – I mean if I was priming it – and you may have done this already. But what I would do is I would use same manufacturer’s primer and paint. So, for example, I don’t think you can go wrong with Rust-Oleum. That’s pretty much one of the best metal paints of all.

I would use the red Rust-Oleum primer – the oil-based primer – and I would let it thoroughly dry after you knock off all the loose paint and sand it and make sure the surface is ready to accept it. That is how you can get the paint to adhere to steel siding. But I would use the oil-based Rust-Oleum primer which, by the way, takes forever to dry. Depends on the weather but three or four or five hours is not unusual. And then, I would use the Rust-Oleum top coat. Again, oil-based. And I rarely recommend oil-based but in this situation, I think that’s what’s going to give you the best adhesion.

Now, Rich, there’s one other piece of advice that we could offer you on this and it comes from a process that’s very – that’s done very often when people work on cars. There’s a product called Prep-Sol – P-r-e-p-S-o-l. And it’s a solvent that’s designed to be applied to bare metal before the primer. You might want to look that up as – I don’t know what – you said you were using a solvent. I don’t know if you were using mineral salt – mineral spirits or something like that – but this is specifically made for it. Just Google it. It’s called Prep-Sol – P-r-e-p – S-o-l. And it’s a cleaning solvent.

RICH: OK. Do I apply it with a brush or a rag or …?

TOM: You apply it with a rag. Use a clean cloth and you apply it – you soak it in with the cloth.

RICH: Yeah, I’ll try that. Thank you.

TOM: You’re welcome. Good luck with that project. Thanks so much for calling us at 888-MONEY-PIT.