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Fold Forming Sterling Silver, HELP!
shannonreeves -
Wednesday, April 15, 2009 - 3:44pm
foldforming Ive been doing alot of foldforming with copper lately, so i decided to try a little on 20 gauge sterling. it became very brittle and basically just fell apart. what am i doing wrong? any suggestions?  Shannon, Sterling silver
Rich Waugh -
Wednesday, April 15, 2009 - 8:31pm
Shannon, Sterling silver will work harden rather quickly and you need to be aware of this and anneal as necessary. A tight fold will harden the silver sufficiently that it will crack when unfolded, if you are using silv er sheet as received form the mill. As delivered, silver is usually in a state called "half-hard", or roughly 50% work-hardened by the rolling process. The folding process takes it the rest of the way to full hard and anything more cracks it. Your best bet is probably to anneal the sheet before you start any folding at all, the anneal again after hard folding and before opening the folds. You might get away without annealing after the first fold, but no guarantees. For proper annealing, the silver needs to be heated to a red heat as viewed in dim light and then quenched. If you quench in pickle it will remove most of the firescale, but be careful not to splash the pickle all over yourself. I usually don't bother fluxing before I anneal as it is difficult to get perfect coverange and the flux is not cheap or eay to remove completely. Your mileage may vary, as they say.  I have to agree and
Jamie Santellano -
Thursday, April 16, 2009 - 8:26am
I have to agree and disagree... I have purchased sheet that is dead soft, however I would still anneal it before hammering, and continue to anneal throughout the process. With sterling silver fire scale is very tough to get rid of, and pickle alone will not clean the silver enough to completely take way the fire scale. I would always paste the entire piece with flux! Fold forming has a lot of texture, so firescoff or flux will help to cut back on the firescale, but buffing will most likely be needed to remove all firescale. When annealing I would make sure the "red" is a "cherry red," or as I said before the milky white glazed flux is a good indicator that the piece has reached proper annealing temperatures. Jamie Santellano  fold forming sterling silver
visitor -
Thursday, April 16, 2009 - 10:15am
I agree with the input that the problem is with over-heating when annealing. If the problem were over-working, it would crack before annealing. I also would suggest trying working with Argentium Silver and fine silver. They are both softer, when annealed, than traditional sterling silver. Each has unique working properties, as do all metals, though---so be sure to read up on how to anneal, etc. In case you are interested, I am teaching fold forming Argentium Silver in mid-May at Metalwerx, in Waltham, MA. have fun folding!  classes
shannonreeves -
Saturday, April 18, 2009 - 6:35pm
i actually came across the class on the internet recently, i would LOVE to take part but right now financially, i am not able. i am really enjoying doing foldforming, and will continue to experiment with it. thank you for the input. Don't quench it right away
visitor -
Tuesday, May 19, 2009 - 6:57am
Don't quench it right away after annealing. Let it cool naturally for a couple of minutes. Quenching right away also work hardens the metal. When working with sterling
Rich Waugh -
Tuesday, May 19, 2009 - 6:05pm
When working with sterling silver (92.5%Ag/7.5%Cu), the appropriate method for annealing is to heat to red and quench immediately - do not wait. Waiting only reduces the temperature slowly, instead of rapidly, and it is the rapid cooling from the transformation temperature that fully anneals the sterling. Yes, it will still anneal if cooled slowly, but it will not anneal as much. Rapid coling, slow cooling, rapid warming, slow warming - none of these will work harden the metal. It is only through the dislocation (compression) of the metal that work hardening happens. Bending creates compression on the inside of the bend, causing work hardening, just as compressing it by hammering does. No amount of temperature change will cause work hardening. There are ways to bring about some hardening of non-ferrous metals through manipulation of temperature, but they are not work hardening. This type of hardening is called precipitation hardening. Rich Waugh  What am I doing wrong?
B.J. Severtson -
Wednesday, May 20, 2009 - 10:38am
Back to the original post. Without getting into the how to of annealing silver. I do a litle fold forming. It sounds like your problem is that you are treating the silver like the copper you have worked previously. Basically you will need to anneal silver more often. You will need to anneal it correctly. of course. Many of the forms I build have in copper required as many as 15 annealings to complete. In silver they would have taken 30 or more. BJ I agree with this comment
visitor -
Wednesday, May 27, 2009 - 6:44pm
I agree with this comment and will also suggest that you use a thinner gage than what you would with copper. I also anneal to the red and quench as others have suggested.  Wait A minute
warren -
Wednesday, May 27, 2009 - 10:54pm
Okay on sterling silver you at least want the red to go away before you pick it up. If you pick it up while still red hot you can damage the piece. Wait a few seconds or so until it is not red at all. It will not affect the annealing. www Metalrecipes -- heat and beat to the desired shape, repeat as necessary. |
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ArtMetal
It sounds like you might
It sounds like you might have over-heated the silver, and changed the structure of the metal. I don't fold form, but in working with silver I know not to over-heat it.
By pasting the surface of the silver with flux, and then anneal. Watch for the surface of the silver and flux to turn a glazed milky white then your done. (It should be soft enough to handle the process of fold forming.) Then pickle it and wash well.
If you overheat the metal you start to change the structure of the silver. While the outside layer of the metal looks solid, the inside becomes liquid. The outer shell of the silver starts to reticulate. this will weaken the structure of the silver and cause it to be brittle and can crack.
I hope this helps...I can't help on the fold forming...Jake would be of great assistance on that one.
Jamie Santellano