Galvanized Steel and Powder Coat on Austin Gates

A metal gate with a powder coat finish and a latch on the post.

Run a thumb along the cut end of a steel gate rail and feel whether the edge is bare metal, zinc or paint. The breakdown sitting on austin metal gate installation apollo pony lists the coatings in the order they fail, and the first failure is almost always at an edge. In Austin, TX the coating matters more than the gate style, because summer sun is hard on finishes and a sprinkler head tends to hit the same spot on the frame all season.

What galvanized actually does

An iron gate hung between two posts at a yard entrance.

Galvanized steel carries a layer of zinc that gives up its own surface first, so the steel underneath is protected even where the zinc is scratched. It looks dull gray and a little spangled. Hot dipped tubing is coated inside and out, while spray galvanizing only covers what the spray reaches.

What a powder coat does

A swing gate with picket infill and a sturdy frame.

A powder coat is a dry polymer that is sprayed on charged and baked into a hard film. It gives the color and a tough skin, and it comes in matte, satin and gloss. It does not protect by sacrifice. A chip lets moisture under the film, and rust creeps sideways beneath the paint from there.

Cut ends and weld spots

Every weld burns the zinc off a patch around the joint, and every cut end of tubing is bare. A careful crew grinds the weld smooth, cleans it to bright metal and covers it with a zinc rich paint before any topcoat goes on. Skipping that step is why one picket bottom rusts while the rest of the gate looks new.

Austin sun and sprinklers

Dark powder coat soaks up heat and chalks sooner under direct afternoon sun. Light colors hold their gloss longer, though they show dirt. Near Zilker Park and the neighborhoods around it, many lots run in-ground sprinklers along the fence line, and hard water leaves white scale that etches a gloss finish if it dries on it day after day. Aiming the heads away from the rails is easier than recoating.

Using both together

The longest lasting steel gate is galvanized first and powder coated second, because the zinc protects the weld zones and the coat protects the zinc. A coat alone is acceptable for a covered, dry gate that is rarely touched. Aluminum needs neither layer for rust, only a coat for color.

Choosing for the yard

Gates close to the Colorado River or a creek bank want the zinc layer. A dry hilltop gate under a tree can get away with a coat alone. A crew looks at where the water goes before it chooses.