# Making a mold with copper bars



## mikeinkaty (Feb 14, 2013)

I recently obtained 11 lbs of copper bus bars mostly 1" wide and 1/4" thick and of various lengths. While looking around for something I could use for a 5 ounce mold I came up with the idea of using the copper bars. I clamped some together making a mold that was 1" x 2" x 1/2" deep. I heated it and sooted it before pouring and it made a nice looking 5 ounce bar of 990 silver. The bottom was perfectly flat and the top was smooth and rounded like a typical loaf bar and there was only a very small indentation in the top. Now I'm thinking of re-clamping the pieces to make a 3" long bar (8 ounces). These poured bars are going into electrolysis so minor copper contamination should be of no concern.

Anyone done this before? By heavily sooting the inside I'm wondering why not do this for the 999+ silver?

Mike


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## butcher (Feb 15, 2013)

I would be afraid of soldering the silver to the copper or contaminate silver, Why not use the copper bars for cementing and make a graphite mold.


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## philddreamer (Feb 15, 2013)

> These poured bars are going into electrolysis so minor copper contamination should be of no concern.


Mike, you know there's a chance of contamination, why use it for your .999+ silver!? 
I agree with Butcher, graphite mold for your pure silver! 8) 
Phil


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## mikeinkaty (Feb 15, 2013)

philddreamer said:


> > These poured bars are going into electrolysis so minor copper contamination should be of no concern.
> 
> 
> Mike, you know there's a chance of contamination, why use it for your .999+ silver!?
> ...



Cause graphite molds cost a lot of money! My one mold (4 ozt loaf style) has made about 130 bars and it is already looking like it's on it's last legs.

ps - my ancestors were born in Scotland!

Mike


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## FrugalRefiner (Feb 15, 2013)

Mike,

There are at least a couple of members on the forum who have graphite for sale at frugal / Scotch prices. :lol: I bought some from Jonn a while back. Great to deal with and very nice material. I don't know if he still has any. You can search his posts. I think someone else listed some recently too, but I don't remember who it was. You can make your own molds for a *lot* less than the commercially available ones.

Dave


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