[TheForge] reclaiming copper

[Dan Brewer]

Melting copper in a steel crucible is like putting hot water into a spun
sugar cup.  It will find a way out.  The crucible will get much hotter than
the contents.  Yes you can get away with it a couple of times but any
weakness in the crucible will soon be found by the molten copper.  The Flux
you need to trap all of the crud you are burning off the copper is borax.
Not just carbon.  Copper oxidizes very rapidly at temp.  The flux keeps the
copper clean.  Copper oxide melts around 2500 deg F.  
Just my 2 cents worth
Dan  

-----Original Message-----
From: theforge-bounces at mailman.qth.net
[mailto:theforge-bounces at mailman.qth.net] On Behalf Of terry l. ridder
Sent: Thursday, June 29, 2006 10:23 PM
To: Sponsored by ABANA
Subject: RE: [TheForge] reclaiming copper

hello;

comments below.

On Thu, 29 Jun 2006, Dan Brewer wrote:

>
> The first is that you will need a bigger furnace.
>

i do have a large crucible furnace that takes a silicon carbide crucible
for melting brass. however, since i am doing this without any help and
that i am living on painkillers ( one every 6 hrs ) for the trashed left
side of my body. the coffee can foundries are more than enough. i am
here 24x7x365 days a year.

>
> Next is that you will need lots of flux.
>

charcoal and coal.

>
> And you will need a real crucible.
>

not sure what you attempting to say here.

>
> The melting temp of copper is not that far off of that of steel.
>

the last time i checked:
copper          1083 deg C        1981 deg F
steel    1370 - 1505 deg C 2500 - 2735 deg F

the steel ultimately depends on the type of steel.

>
> Your crucible will be red hot and fragile.
>
generally are once the crucible furnace is running along.

>
> A clay graphite or silicon carbide crucible is what you will want to use.
>

over kill for my purposes.

> If you are just burning off the insulation use a weed burner.
>

as ralph pointed out there is a big difference between 'bright' and
'burnt' prices that the scrap dealer pays.

>
> Dan in Auburn
>

-- 
terry l. ridder ><>
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