Tips and Information about making jewelry

With this blog, I hope to share my knowledge, successes, trials and errors, student's work, tips, and information about making jewelry.

Wednesday, December 18, 2013

Kiln Maintenance For Metal Clay Artists

There are two types of kilns, brick and ceramic muffle. Mine is a muffle. Muffle kilns heat up faster than the brick type and can easily be moved from classroom to classroom without damaging the kiln. Its best to not move the brick type kiln because, movement can cause the bricks to become loose since they are held together with mortar.

Over time the muffle can develop cracks. I've been told that the cracks shown here in my kiln were caused by opening the door while the kiln is very hot. I'm guilty of this, due to opening the door while enameling. These types of cracks are not harmful. As long as the muffle isn't breaking apart in pieces, and the elements are still secure inside the muffle. As the muffle heats up it expands and the cracks close.

You should occasionally inspect your kiln by checking the thermocouple in the back of the kiln making sure it sticks out from the back of the kiln about 1/2". It can sometimes inadvertently get pushed into the muffle. The thermocouple measures the kiln's temperature and sends this information to the kiln's computer. If it is pushed into the muffle it can't accurately measure the temperature inside the kiln. 

If you are having problems with melting your metal clay while firing, then you should test the thermocouple for accuracy with a kiln tester. Here is a link to my instructions on testing the thermocouple: Testing Kiln.  

Sometimes the door's latch needs adjusting. The latch should lightly catch so that it doesn't shake the kiln. The door doesn't need to close tightly against the front of the kiln. There needs to be some space for the door's material to expand when it heats. If you work with enamels, you don't want the door to shake the kiln when closing otherwise you may find your enamel has fallen off your piece! On my kiln the door latch adjusts by twisting a screw in or out on the latch.  

It’s also good to check the kiln's plug wires making sure they are not cracked or damaged.  If they are seek advice from a kiln repair company.