How to Paint Aluminum Siding

One common question that Danny and I receive on the radio show is, “Can I paint aluminum siding; and, if so, what is the best method?” Great question.

The key to painting aluminum siding is preparation and priming. All of the chalkiness must be washed and scrubbed off, and any flaking paint removed. In a nutshell, you need to start with a clean palette.

Once everything is clean and dry, you’re ready to apply your primer. Here’s where a lot of people make a mistake and, unfortunately, I’ve even heard of “professional” painters who do this. They apply a latex primer.

This is probably the worst thing you can do when painting aluminum siding. Most latex paint has ammonia in it, and that includes primer. Ammonia has a chemical reaction to aluminum, which produces a tiny amount of gas.

Latex paint, by nature, is very elastic, so you end up with an elastic coating with gas bubbles underneath it. If you don’t quite see the problem here just think about how your own insides react a couple of hours after eating two or three bean burritos . . . ’nuff said, right? The gas build-up under the latex primer pushes up and out, which bubbles and flakes the top coat, in other words, it causes the paint to fail.

The solution is to use an oil-based primer specifically designed for metal surfaces. You will have to wait longer for an oil primer to dry, but it’s better than having to re-do everything within a year or two.

Once the primer is dry, top coat with a 100% acrylic paint. If you take this approach to your aluminum siding paint project, you’ll have a long-lasting finish you can be proud of.