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Thread: melting copper

  1. #11
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    I have used copper tubing and pipe as well. It seems to be just fine. I prefer wire because I don't have to clean it or hammer it flat and fold it up.

    I use #14 wire and larger only. I buy only clean #1 scrap. But I don't think lacquer or wire varnish would hurt anything. Seems like it would just burn off at a lower temperature than you pour at.

    Richard
    When I die, Heaven can wait—I want to go to McMaster-Carr.

  2. #12
    It never ceases to amaze me what survives a melt and ends up in the dross.

  3. #13
    I've only melted copper a couple of times,trying to make aluminum bronze.First time melted the copper first(took longer than expected)then added aluminum.Second time melted a heel of aluminum then added copper and it went much faster and smoother.I suspect aluminum may be sort of a flux for copper.

  4. #14
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    copper oxidizes, it loves to pick up O2. If it looks like a melted blob but acts mushy or somewhat solid, I would guess that it has picked up O2. Two solutions: watch your furnace atmosphere, back it down to neutral or slightly carbonizing and add some charcoal or coal to your crucible. The carbon in the crucible is more reactive to the O2 than the copper. Hope that helps. Also the extra carbon in the pot will reduce the oxides back into clean copper.
    kent
    Kent
    There is beauty, power and excitement in simple old technology!

  5. #15
    Quote Originally Posted by jerseydevil View Post
    yes, I'm firing with the front open...

    I have a B tank and an oxi/air torch, but it's a small tip, and it doesn't seem to work much better, plus I have to hold it the entire time.
    I don't find it very difficult to melt copper... it's keeping it in the crucible that's the difficult part. I melt with charcoal and it is difficult to get the temperature high enough while not burning through the steel crucible...

    :sad:

    jf

  6. #16
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    steel crucible...
    Don't do it. For two reasons:
    1. At copper temps steel gets red hot, and it is quite flexible and not at all strong.
    2. Molten copper alloys with steel readily; it dissolves some of the steel crucible and you are left with a Cu-Fe alloy instead of pure copper.


    Richard
    When I die, Heaven can wait—I want to go to McMaster-Carr.

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