Al Sather on sun 7 mar 99
Greetings
Another potter and I are the proud owners of new Skutt 1027 kilns with
enviro vents. We got into an discussion as to if the vent fan should be
shut off during the cool down period. Neither of us saw a necessity of
running the vent, but I felt it should run to keep to motor/fan/vent
cool,
but she was afraid of a too rapid a cool down in the kiln.
Are there any learned opinions as which to do, and why!
Thank you, Al
--
**************************************************
*** Allan Sather (709) 895-0478 ***
*** PO Box 189, RR #1, Paradise, NF, A1L 1C1 ***
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Janet Harper on tue 9 mar 99
Hi Al,
I used an Envirovent with my electric kiln until I moved the kiln outside to
my kiln porch. I always left the fan blowing til the kiln was cool because I
assumed the heat was bad on the fan motor. Now, I don't use the vent and I
don't see any difference between the pots fired with a vent on and no vent at
all. This was firing to ^6.
Does anyone know if I made a mistake moving the kiln to a protected corner on
the porch? It has the computerized control panel and I'm hoping the outside
temps won't hurt it. So far, it is working fine after a winter there, but the
weather was not extreme here in East Tennessee this year. The kiln is not in
a position to get wet but I'm sure the humidity gets to it. Any opinions out
there?
Thanks,
Janet
Janet H Walker on tue 9 mar 99
...if the vent fan should be shut off during the cool down period...
Depends on what you are trying to do and on your glazes. if you have
high gloss glazes that depend on quick cooling to keep their gloss,
then you want to keep the vent on. If you are doing iron reds or glazes
that depend on zinc or titanium to make satin matts or nice frosted
effects,t hen you want to turn the vent off.
I called Skutt after i got my kiln & vent to ask what temp i could
safely turn off the vent. They had to "get back to me on that". the
answer then (1996) was 2000F roughly if I remember right. I figured
out that this really wasn't much below 2200, which is about the target
for cone 6 firing. So i decided I could turn the vent off when the
firing reached peak temp without much risk of damage to the fan.
The fan, by the way, mixes a teeny bit of kiln air with lots of room
air so the air coming through it is not hot. If you put your hand under
the kiln beside the vent even at top heat, it is not very hot. nowhere
near as hot as near the lid. ("Heat rises.")
Anyhow, I have had no trouble with the vent in three years of turning it
off when I get to temp or after the soak. If I'm there. Sometimes it
just runs for three days instead because i'm not there.
...she was afraid of a too rapid a cool down in the kiln...
This is a valid fear, with or without the vent. The 1027 is a very
lightly insulated kiln and unless you fire it down (i.e. keep the heat
on for 4 to 8 hours after you reach temperature) you will not get good
effects with iron glazes. I would say that you should both turn off
the vent AND have a controller to fire down the kiln so that your
glazes have a chance of turning out as they would in a large electric
kiln with lots of thermal mass.
To bolster my claims here, take a look at some of the latest ads (I
dont' remember which magazine) for kiln vents. They say things like
"reduce your firing cycle by up to two hours in the cooldown!!" which
is a marketing technique i recognize from my years int he computer
industry. "It's not a bug; it's a feature". Anyhow, I think you
might want to try it both ways but for my work, I definitely turn off
the vent when I can. (If only Skutt would build in a thing on the
controller which also controlled the vent. Sigh. I just don't want
to have to go design electrical circuits. Yes, it would be "easy" but
the manufacturer should have done it already because it is an obvious
need.)
Cheers,
Jan Walker
Cambridge MA USA
Barry Thomas on tue 9 mar 99
------------------
Allan,
I have a Skutt KM818 with an Envirovent. The manual for the Envirovent =
states
that for slower cooling the vent can safely be turned off when the internal =
kiln
temperature is less than 2000 degrees F. Or, if you have the controller, =
you
can leave the vent on and allow the controller to set the pace of cooling.
Best wishes,
Barry Thomas
(Idaho hobbyist)
....and I quote:
=22------------------------------
Date: Sun, 7 Mar 1999 23:53:03 EST
From: Al Sather =3Casather=40thezone.net=3E
Subject: Skutt and enviro vents
----------------------------Original message----------------------------
Greetings
Another potter and I are the proud owners of new Skutt 1027 kilns with
enviro vents. We got into an discussion as to if the vent fan should be
shut off during the cool down period. Neither of us saw a necessity of
running the vent, but I felt it should run to keep to motor/fan/vent
cool,
but she was afraid of a too rapid a cool down in the kiln.
Are there any learned opinions as which to do, and why=21
Thank you, Al
--
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=2A=2A=2A Allan Sather (709) 895-0478 =2A=2A=2A
=2A=2A=2A PO Box 189, RR =231, Paradise, NF, A1L 1C1 =2A=2A=2A
=2A=2A=2A=2A=2A=2A=2A=2A=2A=2A=2A=2A=2A=2A=2A=2A=2A=2A=2A=2A=2A=2A=2A=2A=2A==
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=22
Candice Roeder on wed 10 mar 99
Hello all,
I've been using Skutt 1027's for about 7 years now. I have 2 of them,
one with the computer controlled function, one without....both have
envirovents.
I fire in an unheated garage. Winter, summer. I live in Michigan, so I
deal w/verry cold days, and hot humid ones. No problem for kiln,
controller or vents.
I was in the habit of shutting the fan off when the kiln load was done.
This was not always convenient...depending on shut off time. Trying to
"catch" the fan at the right time, so temps wouldn't plummet was a
challenge.
Since I got the computerized one, I now "fire down", leaving the fan on
during most of that time. I cool at 150 degrees an hour, down to about
1000 F. I do this when I'm firing matt glazes, or have large flat
porcelain pieces, to prevent dunting.
I came up w/ an idea that has worked well for me. I bought one of those
"outlet timer" things...like you plug lamps into when your're on
vacation? Now I can set it to turn the envirovent off prior to the end
of the firing. If I know the firing will take around 12 hours...I set
it to turn off at 10 hours into the firing. So far it has worked great.
I agree that it would be great if the skutt controller would also
include control of the envirovent.I'm sure someone handy might be able
to figure out how to do it...but not being mechanically nor electrically
competent...I chose the easy way out.
Candice Roeder
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