Aluminium

Hi Can anyone tell me if it is possible to cast aluminium using a kiln? I know that the temperature is more than adequate. Can you heat the aluminium in the kiln at the same time as the mould. Will it oxidise? Should you run the aluminium from a secondary container? I know this is an odd way to approach the problem but I have been asked to do some trial pieces and have a setup for glass casting and don't want to buy foundry equipment to do a few tests. Can anyone help?

Interesting! Make an experiment and let us know. As far as I remember: Aluminum, when heated over 1000 F will react with surrounding oxides -> This reaction will increase the temperature over 2000 F; which is sufficient to melt iron. I am not absolutely sure about the details. Check around.

Regards,

[This definitely isn't the way it's normally done. You will doubtless get more oxidation this way than in a normal melting and pouring process, due to the extended heating time. What are you using for a mold? As long as no moisture or combustibles are present, the mold can be poured cold. So you can cook it a while to remove trace water, then take it to a foundry- they probably won't charge much just to fill your mold. I don't think that you will get a very good casting by melting the aluminum in the mold; the shrinkage and oxidation will combine to sabotage your results, I'm afraid.]

[Yes, it's possible to burn aluminum if you seriously overheat it. It usually is poured around 1000 F.]

Andrew Werby

UNITED ARTWORKS- Sculpture, Jewelry, and other art stuff http://unitedartworks.com http://www.computersculpture.com for 3d design tools

We pour our aluminum at 1300-1400 in our foundry. A few times I have forgotten about the metal and it has gotten up to 1800 or so but it was OK except it picks up a lot of hydrogen gas when it gets that hot. That leaves a lot of pinholes in your casting. I have never burned aluminum and am curious hot it burns at and what it looks like. As for heating aluminum in the kiln, I don't see that there would be much of a problem with that but I do not suggest putting the mold in the kiln. You need to scrape away the slag before you pour the metal so you can't just set the metal on top of the mold if that is what you were planning. As long as you take the metal out and scrape it before pouring I don't think you would have that much problem with oxidation or hydrogen gas. If you don't want to try that, we would be happy to pour your mold if you are close to Tacoma, Washington. Bill