Caring for your Crucible
CRUCIBLES: They come in many styles and one of the most popular is the 2 1/4 inch Ceramic Fused Silica crucible with whip handle.
This crucible is one I sell in my kits or separate and it comes already seasoned so it can be used right out of the box! When used properly, these crucibles can last a very long time. I have a few over 2 years old that have been heated intensely on many occasions, some to the point they are almost see through they are so red. I also use the rejects which come cracked and so far they have stayed together but I wouldn't recommend anyone else doing this.
They are listed at 2800* F with a 20 dwt (31 gram) capacity but I have used 3 ounces (60 dwt) with never any issues. Just use care when going above the recommended capacity. I also suggest eye protection, clothing protection, and an excellent ventilation system to help protect the lungs.
The biggest issue I've found is when inexperienced users buy them, can't get their metal to melt, and then pull out the metal when gooey or pry it out once cooled. DO NOT do this! It pulls off the glazed flux coating which sometimes includes a layer of crucible. This will damage the crucible and possibly cause it to crack during future use. IF this happens, the glaze must be replaced prior to using again so here is how to do it. 1) heat up the crucible slightly with your torch. 2) using a brush with white paste flux, coat the exposed area and then heat it again. The flux will turn into a glassy goo and can be dripped around until it covers the open areas. Keep adding flux until all damaged areas are re coated. In the future, make sure all metal is poured out to prevent this problem.
IMPORTANT:
1) If humid in your area, the coating will become sticky. If this happens, just heat until the white stuff stops bubbling and then add your metal. Use as normal.
Thank you and contact me any time with questions.
