A rust problem on a painted iron door, railing, or fence can be a real eyesore – albeit one that can be put to rest with some good surface preparation and by applying a paint with proven rust resistance.
When dealing with previously painted iron, it’s essential that you prepare the surface properly or you’ll be back at the job before you know it. First, remove any rust that you see using a scraper and wire brush. Then brush off any rust particles that remain, scrub, rinse, and allow the surface to dry completely. Immediately afterward, prime with a high quality corrosion-inhibiting primer. Two coats offer more protection than one.
If you are painting new iron with no sign of rust, just scrub, rinse, and wait for the surface to dry thoroughly, then prime promptly.
When selecting paint, it’s best to choose a top quality 100% acrylic semi-gloss coating and apply it in two coats. Compared to other products, these paints are much tougher and inherently more resistant to all forms of moisture, including humidity, so they offer superior protection against rust.
Tests at the Paint Quality Institute show that many of the highest quality 100% acrylic semi-gloss paints are rust-resistant, but a few perform especially well in this regard. They are:
- Ace Clark + Kensington™
- Behr Marquee®
- True Value WeatherAll®
- Valspar Duramax®
- Home Hardware Beauti-Tone (available only in Canada)
If you’re dead-set on using a flat finish rather than a semi-gloss product, the options are more limited. In our testing, the following four brands of flat paint were more rust-resistant than others we evaluated:
Keeping rust at bay is one of the toughest challenges for paint, but these products are up to it. Do good surface preparation, choose the right brand of top quality 100% acrylic paint, and apply it in two very thick coats. That’s the winning formula to get the best possible protection against rust on anything made of iron.