First Time Firing Cone 6 In An Old Duncan, Help!

[cjvj]

I attempted to fire my old Duncan kiln to cone 6, however it never reached the final temperature to melt the cone.  I fired it twice, once for 12 hours and the second time for 23.  It fires cone 06 bisque and glaze without problems.  Any ideas as to the problem?

[neilestrick]

Are you sure you've got the settings right, that the switch is on 'high'? Some of those Duncans have switches that don't read low-med-high, but rather Overglaze, Ceramic, and Hi-Fire. Make sure you use High Fire. If you've got it set right, then you either have a bad switch, a bad element, a bad wire connection, etc..... Lots of possibilities.

 

First thing to check is if all the elements are glowing when the kiln is on high. If all but one glow, then that element is either worn or broken, or there's a problem with the wire connection to that element. If two elements next to each other don't glow, then you either have 2 bad elements/connection or a bad switch. Ultimately you'll need to put an electric meter on it to figure out the source of the problem.

[Denice]

I don't know how old this kiln is but they use to sell kilns that were only for low cone firings.  My kilns that fires to C6 acts that way when the wires are shot.  Denice

[neilestrick]

Good point. Could be that it's not rated for cone 6. Check the serial plate, it will say max temp for the kiln.

[yarddog]

Neil,

I see that you are a repair tech for L&L. What do you thin about firing an old K14 up to cone 6?

[neilestrick]

First, look HERE for some important info on the wiring configuration for that kiln. Assuming everything is good with the wiring, and the serial plate says it's able to fire that hot, then there's no reason you can't do it. I would open up the control boxes to make sure everything's good in there, like the wires aren't crispy and the connections aren't corroded.