working with silver

No,the matrix of carbon and iron is determined by quench.You can't make the atoms closer by hammering them,and even if you could,it would bve undone at critical temp.
 
Lynn,

I was always to understand that one didn't need flux while using a graphite crucible. The graphite in the crucible (or the charcoal added to the melted metal) sucks up any spare oxygen in the metal that will either react with it or cause it to flow improperly. I am pretty certain that this information can be found in, as Stacy mentioned, "The Complete Metalsmith". If you are interested in mixing your own alloys a good source of clean copper is old ground wires. They are oxygen-free and are plated with silver to avoid corrosion. I'm not sure how the price of such scrap compares to copper casting grain (I'm not exactly sure where to get copper casting grain, for that matter).
The use of new metal ensures that there is only a limited ammount of other crap in the mix. Metal that has been cast once is likely to have oxide on the outside (or inside) and have junk stuck to it like whatever investment you used. I'm not sure to what extent a graphite crucible cleans up the metal.
And Shakudo - If it's me you're refering to, I did go to school for this. I am not an expert in casting as Stacy is but I know what I'm talking about. I'll look on the internet if I want information about how they faked the moon landing...

- Chris

Lynn said:
Chris,
You have given good info! Thanks.
I bought some scrap silver with the intension of casting. In my reading it would appear that a flux (borax?) should be added. I didn't see anything about the need for 'new metal' for casting or the inportance of using a graphite crucible.
Will you elaborate or tell us where to get more information?
Thanks, Lynn
Click to expand...
 
not using the internet to get the right info about working the particular sterling you have??? i guess if you didn't use the internet,you would have to pick up the phone to find up to date info. do you know what happens when you roll or hammer work one of the newer non oxidizing sterlings like "Argentium"? graphite is carbon,when it's gets hot it burns and uses oxygen,but if you are melting in a non inert gas container or using a torch there is still oxygen and a flux is usefull.
 
Not wanting to start a new war here,but... Many jewelers are not totally awed by the new "bright" alloys like argentum.They are mostly used by art jewelery makers.The alloy elements in these metals cause the need to work them differently than sterling.
Graphite crucibles are made from a graphite/clay mix,they don't burn up(at least not too fast).They help control oxidation by creating a reducing atmosphere.However the flux does more than eat up oxygen(that is why I add a bit of powdered charcoal to my flux mix),it reduces the surface tension on the metal surface,allowing the scale,scum,crud and oxides to "flow"to the side of the crucible.As to flux,the only time I don't use it is when melting in a RF casting machine(the metal is melted by high frequency radio waves).Even in a electric melting pot I use a bit with recycled metals.With new casting grain,there is little problem with oxidation.Alloying your own sterling is penny wise and pound foolish.(cent wise and dollar foolish never did catch on?)
Stacy
 
Man, this little thread started a bonfire, didn't it?

I'm interested to know how many of you are also jewelers who use precious metals and stones.

I don't cast, all my work is fabricated.

I'm going to set up a seperate web site for my jewelry. Maybe we could collaborate on the site and create a new market. ???

Who's interested in showing your work with mine and offering it for sale?
 
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