# Cracks in the melting dish



## skyline27 (Jan 13, 2008)

I melted my first buttons tonight. We noticed some cracks in the melting dish after the first melting. It held together for another round of melting. Is this normal or should I get a new dish? We tempered the dish for a long while until it creaked and then heated it some more before adding borax and the gold. What went wrong?


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## Noxx (Jan 14, 2008)

It's normal 

It happen to me all the time.


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## lazersteve (Jan 14, 2008)

Skyline and Noxx,

If you are in a cold weather area, low outside temperatures can cause the dishes to crack from thermal shock if cooled or heated too quickly. 

Steve


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## Noxx (Jan 14, 2008)

Maybe... but I don't think it affects anything...


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## Harold_V (Jan 14, 2008)

Jewelry supply houses used to sell two different types of clay dishes. One of them was a pale brown color. They are prone to cracking, even when well tempered. I suggest you buy only those that are made of a white clay. Temper well before introducing excessive heat, and coat (*interior only*) with a thin film of borax. 

If your melting dishes sit for considerable time before re-use, it's a good idea to dry them (it) before introducing a torch. I used to place mine on one of the burners at low heat for a while. Never lost one to cracking by that method. 

If, by chance, you're using a cupel instead of a true melting dish, I suggest you lose the idea. They won't provide anywhere near the service life of those nice white clay dishes. 

You could guild the lily and buy the round melting dishes that GSP has mentioned before, but I found them unnecessary, and expensive in the scheme of things. 

Harold


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## skyline27 (Jan 14, 2008)

We've melted twice in the cracked dish now. It seems to hold up but makes me nervous. 

Harold, do know a good source of the white dishes you mentioned?


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## socorban (Jan 15, 2008)

You want some great dishes, check out this site below.

http://www.contenti.com/products/casting/170-710.html

Many dish styles and tools, all at great prices. I directed you straight to the good average sized dishes.


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## Harold_V (Jan 15, 2008)

skyline27 said:


> We've melted twice in the cracked dish now. It seems to hold up but makes me nervous.
> 
> Harold, do know a good source of the white dishes you mentioned?



It's been years since I last made any purchases, but jewelry supply houses used to sell melting dishes under the trade name Vigor. They come in various sizes, so you can pick one that is appropriate for your needs. I used the large one primarily, and could melt something like 20 ounces at a time. Too big is better than too small, so don't be timid about buying the largest size, or the next smallest one. These dishes look very much like evaporating dishes (egg shell white in color, not tan), but with thicker walls. They're a wide, rather shallow dish, perfect for torch melting small lots of non-ferrous metals. 

Sorry I'm not more help---I've been out of refining for about 13 years now and no longer know what is available. 

Harold


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