luba@mudfire.com on sat 21 dec 02
We're using downdraft vents on all our electric kilns in the studio... and
recently the question came up regarding at what temperature should the
vents be turned off. Obviously you don't want the vents on after the kiln
has reached the desired cone so that your slow cooling is... well... slow.
But is there any benefit to keeping the vent on all the way up to cone
temp? We fire to 04 and 6 ox. Is there a certain peak temperature at
which point you no longer need to vent?
If so, are there special timers out there that can "talk" to the kiln
controllers or the thermocouple and recognize that they should shut the
vents down at a certain temperature?
Just wondering...
Luba
william schran on sun 22 dec 02
Luba asked about timers for kiln vents. Bailey Pottery Supply sells
their vents with timers. No reason why you couldn't add/adapt your
existing vents with a timer.
Bill
Michael Wendt on sun 22 dec 02
Luba,
Turn off the kiln vent about one hour before you expect the cone to bend in
the kiln sitter.
Look at the kiln sitter tube carefully. You will notice that the sensing rod
that rests atop the cone goes through a porcelain tube that is open to the
outside of the kiln. As a result, if the power vent is on, cold air is
washing over the cone in the kiln sitter and this will give you a false
reading. Naturally, it is always best to rely on a pack of witness cones in
front of a peep hole but with power vents, the same cooling can alter their
reading if the plugs are loose. Power vents can also cause the strange
circular cracks Brad Sondahl mentioned earlier this year if the pot sits
near a leaking peep hole plug.
Regards,
Michael Wendt wendtpot@lewiston.com now a commercial, so stop here and
read no further unless you want a clay sample.
Offer: 25 lbs of Helmer for wood fire flashing slip $5.00 + S & H. Call
Wendt Pottery
2729 Clearwater Avenue
Lewiston, Idaho 83501
1-208-746-3724
wendtpottery.com
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