- If stress has been applied or loaded into a product, coat piece with boric/alcohol, soak at 650° for 45 minutes, allow to air cool. This will relieve the stress without adverse effects such as loss of temper. Standard torch or oven annealing is sufficient to relieve stress.
- How much stress? When reducing sheet or wire, avoid overworking. This can be identified by edge notching, which is undesirable. Reductions of 50% are standard between anneals, 37% reduction is considered full hard.
- Avoid sharp notching. Use a slight radius if applicable, especially if stretching and compression must be applied to the notched areas.
- Use 18K or platinum in key areas instead of low karat or nickel whites. These metals have a much higher tolerance to corrosives.
- Avoid too much heat or excessive time exposure to heat. Allow pieces to cool slowly. Repetitious heating to red zones is not recommended unless sufficient cold work is applied between heats. Avoid dull cutting tools and use a lubricant to avoid generating excess heat.
- Avoid contact with corrosive liquids, solids or gasses. The seacoast and semi-tropical areas produce chlorides which combine with the salts produced through perspiration to form a corrosive element that discolors the skin. Smog fumes filled with particles of silver dioxide and phosphate aso gradually attack jewelry.
- Prong work is of particular concern. Take care to not stretch prongs out of parallel. This increases the angle required to move the prong tip over the stone thus increasing stress and compression. It's the jeweler's responsibility to control and decrease stress. Make it a point to work "stress free."
Precautionary Measures to Avoid Stress Corrosion
By Stuller Technical Resources | October 6, 2011