The crucibles I purchased came from a commercial foundry supply (Larsen Foundry Supply, in Salt Lake City, where I used to reside), and they didn't sell anything that may be suspect. I do not recall the brands they carried, but I was satisfied with the performance I experienced, in spite of the fact that some of them were good for only eight heats. I used a lot of flux (including soda ash, which is very hard on crucibles), so the lifespan I experienced was short, but in keeping with the operations I performed. I used them in the refining of precious metals, not for casting base metals, so my application was somewhat irregular from that of the typical foundry.ShorelineJohn wrote:I hope I am not going down the same road with the one I just bought, the price is not that bad compaired to others, but I ordered it on tuesday and the guy today said he thinks it shipped but he was not sure.
I have been away from melting for almost 20 years now. I have not pursued crucibles in all that time, although I expect I will in the future. I have much to learn about the current market, having been away for so long. As a result, I hesitate to make any suggestions. I think I would recommend you stick with a major US based producer, though, and ensure that your choice is silicon carbide, or graphite/clay, in that order . I think your experience speaks volumes about why.Are there crucible manufactures You would recommend and or web sites? Google doesn't tell one much about quality.
They very well could be. I used clay melting dishes, which are VERY susceptible to fracturing if not heated properly before being put to use. Clay melting dishes were difficult to use, even when properly annealed. The later models were not made of brown clay, and were far more resistant to cracking. I suspect they may have been made of fused silica with a clay bond.The other question I had is could these cracks be caused by not baking it before each pour?
The crucibles I purchased came from a commercial foundry supply (Larsen Foundry Supply, in Salt Lake City, where I used to reside), and they didn't sell anything that may be suspect. I do not recall the brands they carried, but I was satisfied with the performance I experienced, in spite of the fact that some of them were good for only eight heats. I used a lot of flux (including soda ash, which is very hard on crucibles), so the lifespan I experienced was short, but in keeping with the operations I performed. I used them in the refining of precious metals, not for casting base metals, so my application was somewhat irregular from that of the typical foundry.I have been away from melting for almost 20 years now. I have not pursued crucibles in all that time, although I expect I will in the future. I have much to learn about the current market, having been away for so long. As a result, I hesitate to make any suggestions. I think I would recommend you stick with a major US based producer, though, and ensure that your choice is silicon carbide, or graphite/clay, in that order . I think your experience speaks volumes about why.They very well could be. I used clay melting dishes, which are VERY susceptible to fracturing if not heated properly before being put to use. Clay melting dishes were difficult to use, even when properly annealed. The later models were not made of brown clay, and were far more resistant to cracking. I suspect they may have been made of fused silica with a clay bond.If you live where humidity is high, that may be part of the problem. If so, you can address the issue by using silicon carbide exclusively, not even graphite/clay, which is also moisture sensitive. However, if your choice is graphite/clay, you may enjoy success by simply heating the crucible on a hot plate, keeping the temperature below boiling, so the moisture doesn't flash to steam. Once dry, you can then use the crucible without concern. It is very important to expel the residual moisture if your crucible is not made of silicon carbide.A little suggestion for you. We are a pretty friendly bunch of guys here---no flaming---no bad language, no personal insults---so you'd be well served to provide your approximate location in your profile, so folks like me have a clue where you reside. No need to provide an address, just narrow it down to the state, and maybe the county, if you're comfortable in doing so. That way, if someone is local to you and can offer assistance, they'll know to speak up. Some folks won't contribute to those who prefer to remain invisible, and I don't blame them.Harold
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