When Going Gets Rust, It’s Time to Get Tough

Homeowners often deal with rust ineffectively. However, with a range of inexpensive tools and materials at their disposal, homeowners can fight rust and, in the bargain, produce well-protected metal that gives several years of service, even outdoors.

First, clean the surface thoroughly, using a detergent and water. Let it dry, then remove the rust and deteriorated paint. Finally, wipe off the remaining dust with a clean, dry rag and paint the metal. The idea is to start with a clean surface so dirt and oil are not driven into the steel in the process of removing the rust and paint. You should be left with a clean, well-abraded surface that forms a good foundation for the paint.

The most radical rust-removing tool, short of a sandblaster, is a small disc grinder. On the other end of the spectrum is the hand wire-brush and attachments that chuck in an electric drill. Abrasive wheels and cones produced by Dremel work well. If the rust is severe, clamp the work piece in a vise.

The most versatile rust-fighting tool is an electric drill with a coarse abrasive disc. This is handy for curved surfaces. Although not normally thought of as a rust fighter, the belt-sander is effective on flat surfaces, especially if the work piece can be secured to a workbench.

The best foundation for a rust-resisting paint job is a primer that contains at least 84% zinc by weight.

There are two important things to know about zinc-rich primers. First, they work best when the surface is well-prepared. The zinc must make a good metal-to-metal (electrical) connection with the steel. The other point is that zinc reacts with paint resins, especially alkyds, and forms a crude soap. The process, called saponification, can cause the topcoat to peel from the primer.

To prevent this, isolate the primer from the topcoat with an intermediate coat. For example, a product such as Rust-Oleum’s Zinc-Sele primer can be followed by the company’s Gutter Shield product as the intermediate coat and a gloss black alkyd paint topcoat.

To deal with rusty handrails, first remove the loosest layer of rust and deteriorated paint from a handrail using a wire wheel chucked in a drill. Next, use 3M’s Paint and Rust Stripper to remove as much of the remaining rust and paint as possible. Work into tight areas with abrasive strips and pads such as Norton’s Handy Roll and the Flex’n Sand.

After the railing is painted, caulk where the handrail is let into the masonry stoop. This joint is vulnerable to corrosion.

Rust-treating chemicals don’t work well for large and heavy rust-removal jobs, but they’re fine on small jobs.

The most common rust-fighting chemical is phosphoric acid Naval Jelly, which will strip off rust when applied with an abrasive pad.

Rust-Oleum’s rust converter actually converts rust into a paint-ready zinc-oxide film. It is applied after loose rust is scrubbed off.

To clean corrosion off old-fashioned brushed aluminum doors and windows, use aluminum jelly. Don’t use a steel-wool pad in this process. Steel-wool particles will embed in the aluminum and form corrosion in their own right. Instead use a cloth or a plastic scrubbing pad.