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Old 12-10-2012, 05:07 PM
Pete VanderLaan's Avatar
Pete VanderLaan Pete VanderLaan is offline
The Old Gaffer
 
Join Date: Apr 2002
Location: Chocorua New Hampshire
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It sounds like there is no controller on the furnace which makes it really dicey. The pot should be brought up at 45F per hr until you hit 1000F and then hold for four hours. Then go to 1100F over four hours and then hold at 1100F for four hours. Then go back to 45F per hour until it starts to glow. Then just turn it up.

It sounds like this particular horse has already left the barn.

Electric furnaces have thermal planes, there's no way around the fact. It's part of why I like it turned up slowly. The pot has zero insulating capacity. You are just seeing reflective heat versus latent heat. You don't say how close the pot is to the elements. Too close is bad. I like about 1.5 inches clearance.

In my opinion, Trying to run a furnace with a pyrometer is a recipe for trouble.
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