Refinishing a rusted gate without starting over

One eighth of an inch is how far a screwdriver tip sinks into rust that has pitted through, and every teardown austin iron gates preflight sim has logged on a failed refinish shows the same thing: the metal was already gone before the paint went on. An old gate in Austin, TX can often be brought back, with preparation that takes longer than the painting.

Surface rust against pitting

Surface rust is orange dust that wire-brushes off and leaves clean, slightly rough steel. Pitting leaves craters, and when the craters run into each other the section is thinner than it looks. Tapping a hollow rail with a hammer helps: a ringing note means solid wall, a dull thud means the tube is rotted from inside. Bottom rails and post bases rot first because water settles there.

Stripping the finish

Loose paint comes off with scrapers and a wire wheel. Scrollwork and tight corners need hand brushes or a small blasting setup, since a grinder cannot reach into a curl. Old lead paint is common on gates that date to the early houses in Hyde Park and Clarksville, so a sample should be tested before sanding, and the dust kept out of neighboring yards.

What a rust converter does

A converter is a mild acid or tannin liquid that changes red iron oxide into a stable black layer that primer can grip. It helps in pits that a brush cannot clean to bare metal. It does not rebuild lost metal, and it is not a substitute for brushing off the loose scale first. Once treated, the surface should be primed within a day, before moisture returns.

Primer, filler and topcoat

A zinc or epoxy primer goes on every bare spot, with a second coat on welds and edges. Deep pits can be filled with a metal filler and sanded smooth. Two coats of an exterior enamel complete the job, or the gate can go to a shop for powder coat once it is stripped to bare steel, which gives the longest wear.

Humidity, shade and the ground line

Homes near Lady Bird Lake, Shoal Creek and the shaded yards of Tarrytown hold moisture longer than open hilltop lots, and the gate shows it at the bottom rail. Keeping the lower six inches clear of soil, mulch and wet leaves slows the return of rust more than any extra coat of paint, and a bare spot should be touched up the season it appears.