casting Ampco 18 Aluminum bronze???

[Aydelott]

hi ha have a lot of ampco 18 aluminum bronze chips left over from machining my engine block i just got a fire clay crucible and i have no idea what to do we have a heat treat over that can get above its melting temp. but i have know idea what to do how to timper the crucible or anything any help ?? thank you

 

[jasonh]

If it's a new crucible the idea would be to warm it up slowly over an extended period of time to ensure that it is completely dry before you bring it up to full temperature. E.g. 250F for 1 hour, 500F for 30 minutes. Then put your chips in and take it up to the melting temperature. Be forewarned- typically you don't want to melt machining chips. The high area/volume ratio of chips means that there will be a lot of dross as the outside of the chip oxidizes. If you don't have any foundry experience it might be a better idea to start with Aluminum since that's a easier metal to learn with.