Metal hardening is a common metalworking process, as some metals are extremely soft or have been made soft in order to create complex shapes. The hardening process changes the crystal structure of a metal so that it becomes disrupted at an atomic level and cannot be moved as easily. Copper wire, in particular, is often too soft to hold a design and must be hardened. Usually, copper is hardened through work hardening, or deforming, since precipitation hardening is slow for copper.
Things You’ll Need
200-, 400- and 600-grit sandpaper
2 pairs of round-nosed pliers
Cut a piece of copper wire in the desired length, using the wire clippers.
File the edges of the wire down as smoothly as possible. Sand them with the 200-grit sandpaper. Then move on to the 400-grit sandpaper. Finally, finish with the 600-grit sandpaper.
Set up a soldering area in your workroom. Place a large ceramic tile onto a flat surface, then lay a few fire bricks around the edges of the tile to form a wall.
Set up a pickle pot near, but not in, your jewelry soldering area. Add pickle solution to the pot, then adjust the pickle pot’s heat setting to low.
Place your copper wire onto your fireproof ceramic soldering surface. Heat up your soldering torch to a medium flame and apply it to the wire for a few moments to anneal the metal. This will make the copper easier to bend, but will also increase its hardening capacity.
Remove the torch and pick up the wire with the copper tongs. Place the wire into the pickle pot.
Remove the copper wire from the pickle pot once it is cool enough to touch.
Bend your copper wire into the desired shape, using the round-nosed pliers. You can also deform the wire using other types of pliers, mallets and anvils, depending on the shape you need to make.
Let the wire set for a couple hours to fully cool and harden.
Tips & Warnings
- The more you bend and deform the wire, the harder the copper will become. If you overwork a piece of wire, you may make it too brittle to use.
- To soften the wire again after work hardening, repeat the annealing process.
- Another method of hardening the wire is to pull it through a draw plate, which changes the shape or size of the wire.
- Use plenty of caution when working with soldering torches. Make sure nothing flammable is around your work area. And always wear gloves and a mask.