Melting silver

[Steelmar08]

Today I did my first silver melt. After I poured the silver into the mold, I had a black color on top of the bar. Did I do something wrong? Should I re-melt and do this again? I know I had seen something that said you need to add borax, but I didn’t do that during this melt.

 

[pmbug]

Hi Stellmar08, welcome to to the forum. What was your source material for the melt? Was it pure silver or maybe it contained impurities?

 

[Bottom Feeder]

And process — how did you melt the silber?
I've heard you can melt silber in a microwave oven, did you try that?
If not, what kinda furnace did you use?
Photos? Let's see some pictures!!

 

[Voodoo]

Today I did my first silver melt. After I poured the silver into the mold, I had a black color on top of the bar. Did I do something wrong? Should I re-melt and do this again? I know I had seen something that said you need to add borax, but I didn’t do that during this melt.

Silver Dave explained this as well and how he worked through it via trial and error. That black is oxidation. What you have to do is keep a flame on the silver as it pours into the mold to keep it from oxidizing.

It could also be some Sulfur in your pour. Silver Sulfide forms quite readily and is jet black.

 

[Voodoo]

This is a short video and you can see he kinda leaves his torch over the pour. But if you have a decent amount of Black I'm thinking there was a Sulphide contaminant.

 

[Voodoo]

It looks like yes, if you don't have a pure starting material adding a bit of borax is almost required.

Do You Need Borax to Melt Sterling Silver?

Expert guide on borax use in sterling silver melting—when it's essential, when it's optional, and safer alternatives for fine jewelry makers.

jeweltrendpro.com

That also says that CuO is Black as well. So if you started with sterling or anything with some copper you probably have CuO on top.