Prior to assembly, the copper balusters used in this garden gate (standard 3/4-inch-diameter Type-M copper tubing) were placed for about a week in a wooden crate containing sawdust soaked with a solution of muriatic acid and salt mixed with water.
Gary Katz Prior to assembly, the copper balusters used in this garden gate (standard 3/4-inch-diameter Type-M copper tubing) were placed for about a week in a wooden crate containing sawdust soaked with a solution of muriatic acid and salt mixed with water.

To give these copper door panels their patina, the author stacked them in layers inside the crate, with the layers separated by sawdust saturated with the acid solution.
Credit: Gary Katz To give these copper door panels their patina, the author stacked them in layers inside the crate, with the layers separated by sawdust saturated with the acid solution.

I like the look of copper, but this versatile metal takes a long time to oxidize and until it does, it stands out like a shiny new penny. So on a couple of recent projects, I developed my own technique for jump-starting the oxidation process and creating that aged patina that I like.

I mixed up a potion containing one quart of water, one ounce of muriatic acid, and one tablespoon of salt, then sprayed the solution on a few test pieces of copper, using a typical spray bottle. That technique sort of worked—but the patina wasn’t thick enough and took too many coats, and I had to spray the test pieces every day for nearly a week. And the technique definitely wouldn’t work well on the copper pipes that I wanted to insert in an entry gate (see “Craftsmanlike Gate,” Jul/Aug 2015)—the solution just ran right off the pipes.

I couldn’t soak the pipes in the solution, either, because the reaction requires evaporation and oxygen. So I set the pipes in a wooden crate with layers of sawdust, poured in the mixture, and let my experiment sit outside for about a week. The solution slowly evaporated, the sawdust dried out, and what was left was copper that looked like it had been around for years.

I did the same thing with the copper panels in my living-room cabinet doors. I stacked them in layers—soaking the sawdust between the layers in the acid solution—then set the box outside to dry. Worked like a charm.

Gary Katz is a presenter at JLC Live and a frequent contributor to JLC. He lives in Jacksonville, Ore. KatzRoadshow.com