I’ve got a large Sierra kiln for doing burnouts. It holds sixteen 2
1/2" diameter flasks.
My standard casting procedure is to invest the flasks, let them sit
for 2 1/2 to 3 hours, prepare them and start the burnout.
I let it sit at 250 degrees for 2 1/2 hours (to dry out the flasks),
then ramp up to 700 for 2 hours, then up to 1300 for a while and back
to 1000 to cast. I normally start burnouts late at night, and cast
the next day.
This past Saturday I started a burnout in the middle of the
afternoon, and left for a while. When I returned to the shop during
the 700 degree phase of the burnout. I found water dripping down the
front of the kiln below the door. It was running onto the digital
control panel. The display was going nuts–it was displaying random
shapes instead of time and temp like it normally does.
The burnout continued to proceed, and by the time it was ready to
cast, the display was back to normal. This can’t be good for the
I’m assuming the water is coming from the moisture in the flasks, as
I see no other place else from which it could have originated.
Obviously the 2 hours at 250F isn’t drying them out.
What can I do differently to prevent this from continuing to happen?
And is it safe to put a line of silicone sealer above the top of the
digital control panel to keep moisture out of it? The front of the
kiln gets warm during burnouts, but not too hot to touch.
Feathered Gems Jewelry