Melting copper in electromelt

Jewelry Discussion
1

Hi, I am new to this forum, but have been making jewellery for a
while. Just wondering if anyone has any experience melting copper in
an electromelt furnace. I think, according to Rio Grande, the top
temp of the furnace is 2040deg which is pretty close to the melting
point of copper. Is it gonna work?

Cheers,
Chris

2

I would have said no, but the solidus (melt point) and liquidus
(flow point) of copper are the same temperature.

Give it a go, but I would think that for elemental copper you would
need to get the right temperature.

Regards Charles A.

3

Wikipedia seems to indicate that pure copper melts at 1984.32 F. The
upper range of a Kerr Electromelt tops out at 2000 F.

Maybe?

Andrew Jonathan Fine

4

Andrew,

Wikipedia seems to indicate that pure copper melts at 1984.32 F.
The upper range of a Kerr Electromelt tops out at 2000 F.

That 2000F is a max, the thing uses nichrome elements which fail
above 2000. Maybe they have swittched to a higher temp wire since I
toasted one a few decades back. No superheat possible and a 1% error
in the controler and you have a dead unit.

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

5 
That 2000F is a max, the thing uses nichrome elements which fail
above 2000. Maybe they have swittched to a higher temp wire since
I toasted one a few decades back. No superheat possible and a 1%
error in the controler and you have a dead unit.

Wonder if you could use a Kanthal A1 in that to soup it up a bit?
You’d have to do the calculations of course, otherwise you can have
some unexpected fun.

I burnt out an enameling kiln (very easy to do if you put the wrong
stuff in it :wink: ). I threw in a length of Kanthal A1 just to see
what would happen (I was very bored that day). A very interesting
result. Heated up the room for a very short time before I melted the
wire.

It would also depend on the failure temperature of the refractory in
the unit.

Regards Charles A.

6

I have used the Kerr furnace to make shakudo. I use 2 to 4% gold
which, I’m sure acts to bring the temperature down, but the copper
needs to melt first before the two metals can interact. It’s harsh on
the equipment, but it seems to work.

good luck, Tim