[TheForge] one time use crusible

[xlch58 at swbell.net]

don schad wrote:
> On Fri, Jun 6, 2008 at 12:50 PM, David E. Smucker
> <davesmucker at hotmail.com> wrote:
>   
>> Weld a bottom to a short section of pipe, and the line with clay, one of the
>> fire clays is best but even local clay will work.  Let the clay air dry.
>> Then and this is very important -- bake the whole thing in your oven for a
>> number of hours.  You want the clay bone dry (no water in molten metal).
>>     
>
> I don't think that you necessarily need the clay in the melting pot.
> Probably just weld the bottom on the tube and toss the stuff in there.
>
> I used to use stainless steel cook-ware (like bowls, etc) to melt
> Aluminum because it was easy to get and pretty cheap.  These were
> fairly thin walled, but they would work a number of times until the
> crumbled.   I think your Cu will require higher temps, so probably a
> thicker wall steel would be better.
>
> Also, I don't about about bronze, but w/ casting Al you want to bubble
> an inert gas through the mixture to keep He bubbles from forming.
>
> don

Aluminum casting practices differ significantly from copper, brass and 
bronze.   It is a lot more forgiving.   Copper will aggresively eat at 
your steel crucible, and the strength of the crucible at copper melting 
temp is not near what it is at aluminum.  If I was going to try it, I 
would definately try doing a creamic wash in the steel crucible.  Then 
again, your a blacksmith and a craftsman.  There are many hobby casters 
out there that have the carbide crucibles that will handle this, what 
they don't have is the skills to forge a decent pair of crucible tongs, 
which they have to pay top dollar for to get one that fits their 
crucible tight.  Do some bartering and I expect someone will cast it 
with you using their crucible.  The group :

 http://groups.yahoo.com/group/castinghobby/

is where many caster hang out all over the country.


Charles



Charles