[Mark McCombs]

I need to re-fire a ^6 ox load and get to the proper temp. Programming error on my part.

Do I use the same cones that have seen the same heat work as the ware, or do I use a new set of cones?



Thanks.

[Arnold Howard]

Mark McCombs, on 11 February 2013 - 10:36 AM, said:

I need to re-fire a ^6 ox load and get to the proper temp. Programming error on my part.

Do I use the same cones that have seen the same heat work as the ware, or do I use a new set of cones?

Several years ago I refired cones and compared them with new cones. I wrote, "If the kiln shuts off within 100F / 56C of the cone’s maturity, and the kiln temperature drops 50F / 28C, do not reuse the cones. They will not bend properly. This is because a hard shell will form on the cones. If you are not sure how hot the kiln fired before it turned off, use fresh cones in the next firing."

The link shows a photo of the refired cones and the new ones.

http://www.paragonwe...ter.cfm?PID=361

Sincerely,

Arnold Howard
Paragon Industries, L.P., Mesquite, Texas USA
ahoward@paragonweb.com / www.paragonweb.com

[Mark McCombs]

Thank you.



I do know that the temp hit 1945F.

[Mark McCombs]

I now have both new and slightly used cones in the kiln.



Thank you, Arnold.