My crucible literally melted

I was doing a copper melt and my graphite clay crucible melted

 

WILD GUESS based on the damage, your crucible is too large for your furnace, and was probably not centered.
need to know more about your entire rig, and some pictures to make an informed oppinion,
definately want to know your crucible source so I dont get any there,

V/r HT1

 

I bought the crucible from Amazon. It probably wasn't centered because of the pooling metal in the bottom of my foundry I can center it but when the floor melts the crucible shifts. I have a helium tank foundry with a propane torch. I'll add photos when I get home.

 

Happened to me recently in my electric furnace. Just 1 copper melt and 2/3rds of it oxidized away. Was an unbranded pure graphite one from China. Definitely need to invest more next time.

 

I'm starting to see a pattern here, it's going to be one of those cheap ones with flowerpot clay with lots of fine cracks and tiny lumps of previously fired clay mixed in and not enough graphite.

 

this one did last at least 10 meltings but I had noticed that it was becoming more and more elastic each time.

 

I've had my go-around with cheap ones and will probably have more. Trying to acheive high temps to melt bronze really punishes the cheap clay-graphites. I think it's the air that really beats them up. By contrast I have a #18 that I use only for aluminum and after 10 or more heats it's still in excellent condition.

Pete

 

The one I used for aluminum cracked and it was a more expensive crucible

 

No direct flame impingement! This will shorten the life severely of any quality crucible.

 

Thanks, I had no idea. I guess I'll know now.