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Specialty Chemistry Forums => Citizen Chemist => Topic started by: metalriffzz on November 20, 2005, 12:19:59 PM

Title: Casting temps and crucible durability
Post by: metalriffzz on November 20, 2005, 12:19:59 PM

I'm looking to buy a casting crucible to melt aluminum and possibly copper, and I have two choices:

The cheaper alumnia crucible with a max working temp of 1750 C
or
The more expensive MgO crucible with a max temp of 2500C

I know I could probably get away with the cheaper one at least for aluminum but I'm looking for some second opinions.

Title: Re:Casting temps and crucible durability
Post by: constant thinker on November 20, 2005, 09:37:12 PM

http://www.backyardmetalcasting.com/index.html

Check that site out. May help some.

Title: Re:Casting temps and crucible durability
Post by: Grumples on November 22, 2005, 08:45:16 PM

The MP of aluminum is about 700C, while the MP of copper is about 1100C, both well within the alumina crucible's heat range.  

You may also want to look into various graphite crucibles- I know for a fact that some of those can take up to 3000C (graphite crucibles are typically very cheap if they are small, but get exponentially more expensive as the get bigger).

Title: Re:Casting temps and crucible durability
Post by: metalriffzz on November 22, 2005, 09:06:29 PM

Yeah those graphite ones don't look too bad. What about durability? I think I might spring for an electromelt furnace if the opporitunity presents itself.

Title: Re:Casting temps and crucible durability
Post by: limpet chicken on November 22, 2005, 11:54:34 PM

For melting the metals, look in the technochem section of www.sciencemadness.org for posts by Axehandle, he has built a few furnaces himself, pretty good ones too :)