Copper casting problem

Jewelry Discussion
1

Hi all.

I am thinking of making silver/copper mokume gane. I have bought pure
99.99% copper to cast it on sheet. I have tried to melt it in
crucible but there is the problem. Metal has started melting in to
bigger lumps but then it stopped. I have big propane torch that can
reach 1800C so it isnt temp problem. I have added HUGE ammount of
brax so it isnt problem too. Any ideas how to solve that problem?

Cheers, Mark

2

Mark

I am thinking of making silver/copper mokume gane. I have bought
pure 99.99% copper to cast it on sheet. I have tried to melt it in
crucible but there is the problem. Metal has started melting in to
bigger lumps but then it stopped. I have big propane torch that
can reach 1800C so it isnt temp problem. I have added HUGE ammount
of brax so it isnt problem too. Any ideas how to solve that
problem?

The melting temp of Cu is 2000 degrees F but you need a lot of BTU
(as in really big flame.) 1800C (3272F) sounds good in add copy but
is close to the theoretical max on a very good day here on earth.
Propane and air maybe 2400F. Big mother torch and maybe, not my idea
of a fun day :slight_smile:

jeffD
Demand Designs
Analog/Digital Modelling & Goldsmithing
http://www.gmavt.net/~jdemand