# Clay crucibles are not for me. I need a new route. Graphite?



## The Green Team (Jan 8, 2009)

I have been cutting into the clay crucibles. This results in a glass like 
entrapments of Gold beads and in some case large almost button size 
beads.

I am using a couple of large, but different style torches. I don't think I can pull back the temp enough and the pressures (i tried t reduce) are too 
great. My filtrate Au is at large risk.

I am willing to buy what ever is best. Looking for pointers. 

Should mention Platnum Group Metals are next up.

Electric or gas furnace?

If I should down size torch or switch from propane to hydrogen that is fine.

More than 1 solution is always and option. 

Thanks,

Levi
714-852-1300


----------



## Palladium (Jan 8, 2009)

Unless your just just going to be melting some outrageous amounts i would think you wouldn't need anything other than an Acetylene tourch like metal shops use. You can use the Acetylene smoke to blacken molds for pouring your gold into.


----------



## Noxx (Jan 8, 2009)

When I use MAPP to melt gold, I melt it on an insulating ceramic blanket (like Kaowool). It starts to melts in about 30 seconds. Use only a few borax crystals because borax eats ceramic blankets in not time...

Here you can see : (Isn't that fantastic ?! )

http://www.youtube.com/watch?v=_HRArtpB-7k

P.S. The beads in my avatar came from this melt.


----------



## Oz (Jan 8, 2009)

The Green Team said:


> Should mention Platnum Group Metals are next up



He will probably want a hydrogen torch if he is getting into platinum group metals. The acetylene plays havoc with them.


----------



## Oz (Jan 8, 2009)

That is neat Noxx, melting right on the blanket. Do you worry about losses, especially the velocity of the torch gas against powder without a containment to catch blowing gold?


----------



## Noxx (Jan 8, 2009)

I never experienced gold being blown away by the torch. Of course I probably loose 1 thousand of a gram. My powder was not very fine particles. Also, don't forget that gold is heavy !


----------



## Lou (Jan 8, 2009)

For gold and silver, you can not go wrong with a jeweler's clay melting dish--most are kaolin from what I understand. If you want to melt larger quantities, then perhaps you should consider manufacturing your own furnace and purchasing a small fused silica crucible. If you felt so inclined, you can easily melt gold in a clear quartz crucible with a cover! Big torch? Big deal! With a cover, you don't have to worry about blowing it around.

For melting platinum and palladium alumina crucibles are the way to go. You can use fused silica for palladium, but it is a real stretch with platinum. Rhodium can be melted in alumina but your crucible life is greatly decreased--zirconia or magnesia are best used.


Lou


----------



## butcher (Jan 9, 2009)

kool kawool idea, how about pressing some to a dish with hydraulic press (maybe some clay or old crushed crucibles?)and loose stuff on bottom for insulation,


----------



## Lou (Jan 9, 2009)

I don't like kaowool for the same reason I don't like asbestos--lots of friable fibres are made that blow about, and sometimes into your lungs...


----------



## butcher (Jan 9, 2009)

I have used them both to rebuild industrial steam boilers and repair piping,
most of the early years there was no asbestos scare, we used the powder without masks, so far the xrays only show few spots on my lungs, I have breathed so much of that crap.like smoking I would not recommed it. I like the idea and a damp mask and wind at my back I would like to try it out.


----------



## Lou (Jan 9, 2009)

Butcher,

I too also worry about my exposure to asbestos. Most of the stuff I worked with was long fibre high quality asbestos, but I know I've been exposed as well.

I also am concerned about my exposure to silica, particularly from glassblowing and working with quartz.


Lou


----------



## butcher (Jan 9, 2009)

Yes Lou to me it is just amazing what our bodies can take and still keep on ticking, what a marvel, and Your advise was taken seriously, as many of these things our lungs cannot discharge and build shells around them which may one day cause more problems such as cancer. I was not in the least trying to downplay your Advise.


----------

