I‘m making a necklace pendant out of 20 gauge copper wire and I can‘t get anything to hold the different pieces of wire together. I‘ve tried soldering them and I‘m not sure if I‘m just using the wrong type of solder, but that didn‘t hold up at all. I would prefer a solution that doesn‘t require welding, but if that‘s what it must come to, so be it.
Soldering should work fine. Make sure you have rosin core solder made for soldering electronic parts. it should be as fine as or finer than the wire. And a soldering iron designed for electronic soldering. These are small, perhaps 25-50 watts. Don't expect the joint to be as strong as the copper wire, but it should hold up to some abuse. Brazing is your next alternate, but that requires even more equipment and practice. The strength increases as more of the wires are in contact with each other. You might think of getting some very small gage wire, perhaps #36, and wrap that around the connection a few times. Soldering: Practice first. A few hints: keep a damp rag handy. Tip of iron should be smooth and have an even coating of solder. if not apply solder until the tip is covered and wipe off excess with the rag. The pieces should be mechanically held together, for example, by twisting the ends together, if possible. If not, use mechanical clamps of some sort to hold them into position. You need both hands free. Touch the iron to the junction of the two pieces and touch the solder end so it is where the iron tip touches the copper. The solder should almost immediately flow down and over the junction. Remove the iron. Do not move the wires until the solder has solidified. If you move it, you get what is called a cold solder joint which is very weak. Wipe off the iron when done. .
Solder is usually toxic, so I wouldn't use it in a necklace; besides it wouldn't work too well anyway.
