I have a question for the metalsmiths out there. How do I get the spring back into a sterling silver money clip? I made this clip and was adding some embellishments. I added gold letters to the back and cut out a portion of the front. I soldered on bezels for two gemstones that I’m going to set. The problem I’m having now is the clip has lost all of its spring. It will no longer hold money as it should. The silver is now either too soft or too hard to bend. I think I need to “temper the silver.” However, I can’t find anything in my books dealing with this problem. Also, I don’t have a kiln. Does anyone have any advice for repairing a sterling silver money clip?
Thanks for your help in advance!
Cindy in Virginia
Work Hardening A Sterling Silver Money Clip
I’ve been a goldsmith for nearly 40 years. First off, correcting your situation isn’t exactly a project for a novice. However, if you have some experience and want to try the repair yourself, I do have some hints and some warnings.
I haven’t seen your piece, but it sounds as if you have annealed or softened the clip. In order to return the spring to this piece, the metal needs to be unbent and then worked back into a bend. First, use a small raising hammer, then a planishing hammer, and strike very light, disciplined blows. Next, you’ll need to file, clean, and polish the clip. An experienced silversmith could work the sterling silver money clip with a rolling mill or similar device and bend it back with smooth jaw half-round pliers (preferably chrome plated).
The pitfalls of doing these repairs are:
- If you hammer too much, the metal gradually becomes fatigued and could break. It could also become predisposed to breaking after just a little use.
- Hammering or drawing could distort the bezels and lettering you’ve already done. It could also distort the whole money clip.
This should cover how to correct it.
Use A Mandrel To Hold The Shape Of The Curve
Jewelry metals like sterling silver can be work hardened to return lost “springiness.” I have one suggestion. Use a mandrel or make a mandrel out of a brass or aluminum rod to hold the shape of the curve of your sterling silver money clip.
Hope this helps,
Joe Volkel, Long Island, New York
Re-Hardening Sterling Silver In A Kiln
If you quenched your sterling silver money clip rather than letting it air cool each time you soldered a bezel, you probably annealed your piece. If you can get access to a kiln or temperature controlled oven, you can heat and re-harden the sterling silver.
Heat the clip to 280º C and hold at that temperature for 2 and 1/2 hours. This will allow the metal crystal structure to re-form. Quench in pickling solution, rinse, and polish. You should find that most of the original hardness has returned.
This information can be found in The Complete Metalsmith: An Illustrated Handbook by Tim McCreight.
Hope this helps,
Brinell Hardness Numbers For Sterling Silver
Here are the Brinell hardness numbers (BHN) you can achieve on aging annealed 92.5% fine silver/7.5% copper sterling silver.
- Heating to 300º C for 30 minutes gives a BHN of about 125 maximum. Longer heating reduces the hardness.
- Heating to 250° C for about 2 hours gives a BHN of 155 maximum. Again, longer heating reduces the hardness.
- Heating to 200º C for about 8 hours gives a BHN of about 158. Longer heating at 200º C will slowly reduce the maximum hardness obtained.
Just for your reference, in case you decide to heat and re-harden your sterling silver money clip.
Carl 1 Lucky Texan