Metal Mix Up: How to Hide Solder When Soldering Copper
Hardly a week goes by that I don’t get asked how to solder copper or other alternative metals, like brass and bronze, to each other or silver. Even though copper and brass solders (wire and paste) do exist, they’re not always on hand. Here’s a great trick for making perfectly invisible seams and hiding the solder when soldering copper with silver solder. (Originally published in Lapidary Journal‘s Dec. 9, 2008, “Flashcard” newsletter by Helen Driggs).
Copperplate Accidentally on Purpose
by Helen Driggs
Something in the December (2008) “Ask the Experts” column of Jewelry Artist really started my noodle cooking. Thomas Ogden of Bainbridge, New York, wrote in asking about copper-colored solder (don’t get excited, there isn’t one!) to avoid obvious silver seams when soldering copper pieces. I started wondering “what if . . .” and doing a few experiments on my own. [Helen’s update: Copper solder is available now. I haven’t tried it yet but I will report on it when I do! Meanwhile, this handy trick still applies.]
As beginner metals students, we were practically threatened with death if we got steel or iron in the pickle pot. My teacher said, “If you don’t want everyone in class to hate you forever, do not ever put steel tweezers, binding wire, or sheet in the pickle pot ever, ever!” Why? Because steel will cause the suspended copper in the pickling solution to plate the silver with copper.
Zing! Brainstorm! I could see where copperplating somebody else’s silver piece by accident would be bad, really bad. But what if you wanted to copperplate something made of silver so it didn’t look like silver anymore? Over the years, my teacher’s speech was such a deterrent that I have never accidentally copperplated anything (death threats equal good work habits in my world), so I didn’t know it would be true without some serious chemical investigations. First, some less than perfect soldering was in order, for demo purposes, mind you.
Then on to the chemistry. Since I read Thomas’ letter, I have been hoarding a super-saturated batch of pickle to test the theory. That pickle is blue–I mean blue the color of blue Kool-Aid blue. There is enough copper suspended in there for a penny to just spontaneously form and rise out of the Crock Pot all on its own. What would happen if I purposely introduced steel into that saturated pickle to cover up offensive silver solder seams that form when soldering copper?
As you can see, there is some potential here. If you like the look of copper but hate the visible joins, try this experiment for yourself, but don’t use it as an excuse to be sloppy! Practice getting clean, neat joins knowing you can plate over mistakes, and when you do graduate to silver, you’ll be a real soldering pro. –Helen
Get More Tips and Tricks for Soldering Copper
Learn more about soldering copper and working with alternative metals like copper, brass, and bronze, in our eBook 10 Copper Jewelry Projects Plus Brass and Bronze.
Originally posted December 7, 2012; updated February 2, 2019.