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How to Harden Silver

Silver is an extremely malleable metal, which makes it popular to use in craft projects, jewelry making and bead making. There are different grades of silver, and different methods required to harden those different grades, including work hardening, hammering, and kiln firing. Fine silver is 99.9 percent pure, and sterling silver is 92.5 percent pure. There is a relatively new sterling silver on the market called Argentium, which is 92.5 percent pure, and the easiest to work with and harden. A simple knowledge of the differences will be extremely helpful in bending and hardening silver for any project, and a kiln can be an excellent addition to a jeweler's studio.

Things You'll Need

Furnace or kiln
Boric acid
Alcohol
Flush cutters
Soldering pad

Instructions

Working With the Silver
- 1
  Silver comes in a coil when you purchase it, and you will need to straighten it before working with it. Using a pair of flush cutters, cut the silver and straighten the wire. Be careful while cutting, as pieces of silver may fly off and be projectile. Keep in mind that silver is a malleable metal, and just manipulating it will actually begin to harden it. Be careful in overworking your silver, though, as it may become brittle and break if bent and manipulated too much.
- 2
  Sterling silver is often used for different jewelry projects, such as wire wrapping, fused glass bails, rings and necklaces. To work with sterling silver, place your silver in a kiln or furnace that is heated to a temperature of 1200 F. Heat the silver piece at this temperature and immediately remove and quench it in water; then heat the item for one hour at 600 F. After one hour, allow the silver to cool on a bench in a solution of boric acid and alcohol.
- 3
  Fine silver is typically too soft to work with as a stand-alone project; however, artisans often use it in glass fusing to make bails and other small parts for jewelry projects. Working with fine silver is similar to working with sterling silver. Fine silver is 99.9 percent pure, so you need to take more precautions. Follow the same guidelines as for sterling silver, keeping in mind that heating fine silver in a kiln or furnace will make it soft and give it a whiteness that you will need to remove. After the silver has cooled, tumble it in a tumbler with stainless steel for 30 minutes to harden it and remove any tarnish, film or stain.
- 4
  Argentium, like sterling silver, is 92.5 percent pure, but instead of copper, it is 7.5 percent germanium, which leaves the silver relatively tarnish free. You can replace sterling silver with Argentium in any project, so artists also use it for wire wrapping and similar projects. It is also easier to harden. Heat the silver in a furnace or kiln at a temperature of 580 F for approximately 45 to 60 minutes, and then allow it to air cool on a soldering pad until it is at room temperature. If you quench the silver prior to placing it in the oven, you will achieve a silver of greater hardness.

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