Converting Ceramic cone numbers to temps

tom suter · Post by **tom suter** » Fri Nov 14, 2003 12:16 am

Can anyone that is fimilar with ceramic cones tell me what cone 15 and cone 17 is approiximately in regular temps. Thanks

Ron Coleman · Post by **Ron Coleman** » Fri Nov 14, 2003 12:17 am

Try these

http://www.ortonceramic.com/Center/cone_ref.html

Ron

Lynne Chappell · Post by **Lynne Chappell** » Fri Nov 14, 2003 2:03 am

The temperatures vary a lot with the speed of heating. The usual charts from ceramics people are for a pretty slow rate of heating. Also the small cones that go in the kiln sitter bend at a different temperature from the large cones that you put on the shelf to test the temperature.

With the cones in the kiln sitter, I use cone 015 for an almost flat fuse so, in my kiln with my heating schedule it would be equivalent to about 1430F. Cone 017 is a high slump/low tack fuse or about 1350F. It does vary a lot with the rate of heating though. That's the best part about using cones for firing if you have manual controls. They will adjust for the fact that you might forget to turn the kiln to high until an hour after you should have, and it will trip at a lower temperature. The glass comes out pretty consistently from one firing to the next, even with big variations in the actual firing cycle.

Jim Walch · Post by **Jim Walch** » Fri Nov 14, 2003 9:57 pm

OK.....For slumping why not just use a small strip of the glass about the size of a cone instead of a cone! Twenty-five + years back before controllers were around this is what I used for bending lampshade panels. Works great.