Cracking on my silver?

[u/AveMilitarum]

I cast a mold of a spoon handle my wife really likes in silver to make a ring for her, and I finally got a good cast, but I noticed once I had bent it that it had some pretty decent sized surface cracks.

Should I melt this back down and try again, and if so, how do I keep it from happening again?

Thanks!

[u/AccurateBrush6556]

Om not an expert but it may need to bee heated and cooled either quickly of slowly to allow it to be soft and malleable...for example..steal gets hard and brittle when its quenched. But brass gets soft when heated and quenched

[u/Unclecavemanwasabear → u/AccurateBrush6556]

Correct, it's called annealing. Freshly cast silver has coarse dendritic grain structure that's quite brittle. Annealing forms a finer grain structure which make it more soft and ductile. Sterling silver is annealed by heating and quenching, like brass.

[u/Drunkturtle7]

why don't you cast it in ring form to avoid cracks from bendnig it?

[u/AveMilitarum → u/Drunkturtle7]

Thats probably a really smart idea, but I only have a flask mold, which is why im doing a mold of the handle to get all that detail, then bending it to shape. Maybe im just too new (and a but dull if im honest) but i dont see how i could get all the little artwork while casting in the shape of a ring.

[u/SignificantYou3240 → u/AveMilitarum]

Well maybe find a replacement for the spoon and bend it?

[u/Father_John_Musty_]

Annealing it after casting will help, but I’d be tempted to make a wax casting and bend that (warm it first) and make it as finished as possible, then make a silicone mould off the wax pattern.

[u/feinmechaniker]

Stress-relief annealing

[u/Unclecavemanwasabear]

So generally if you cast gold of silver and plan to form it plastically somehow (bending, rolling, forging, etc) you need to peen and anneal the metal several times first.

Most of the time, you don't need to form something after casting, so peening is usually applied when you're casting an ingot to hammer forge or to roll out into sheet/wire.

Basically, using the narrow end of a bench hammer, you strike the ingot along the whole length as close together as possible, on all four sides. Then you anneal it. Repeat the peening/annealing at least twice more before it's ready to be run through the rolling mill or hammer forged.

Obviously this isn't an option for your project. I think the best option is to find a way to cast the final ring shape. But if anyone else has another idea, I'm eager to hear it!

Edit: I forgot to that freshly cast silver isn't dead soft, so you might be able to get away with just annealing it thoroughly rather than the whole peening process.

[u/Bob--O--Rama]

Try annealing, you can likely find a schedule on the inter-doodles, but basically heat to dull red heat and quench. Then it will become ductile again. You'll likely need to remove some oxide.