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kiln blanket

updated thu 27 apr 00

 

Barney Adams on tue 20 oct 98

Hi,
I'd like to reduce the heat loss from the lid of my Skutt 1027.
I was thinking of using some kiln blanket material to seal around the
edge of the lid, but I'm concerned about the health hazard.
Any comments?

Barney

lpskeen on wed 21 oct 98

Barney Adams wrote:
>
> ----------------------------Original message----------------------------
> Hi,
> I'd like to reduce the heat loss from the lid of my Skutt 1027.
> I was thinking of using some kiln blanket material to seal around the
> edge of the lid, but I'm concerned about the health hazard.
> Any comments?
>
> Barney

What health hazard? IMO, this is a really good idea; I have been
considering it for my old Paragon. The dealer suggested to me not to
use a whole blanket of the stuff, but just to use a "collar" of it
between the lid and first ring - where you can see the light coming out
when the thing is on HIGH.
--
Lisa Skeen ICQ# 15554910
Living Tree Pottery & Soaps http://www.uncg.edu/~lpskeen
"The hottest places in hell are reserved for those who, in times of
great moral crisis, maintain their neutrality." -- Dante

"The opportunity to be threatened, humiliated and to live in fear of
being
beaten to death is the only 'special right' our culture bestows on
homosexuals." - Diane Carman, Denver Post, October 10, 1998

the cat lady on wed 21 oct 98

At 09:45 AM 10/20/98 EDT, you wrote:
>----------------------------Original message----------------------------
>Hi,
>I'd like to reduce the heat loss from the lid of my Skutt 1027.
>I was thinking of using some kiln blanket material to seal around the
>edge of the lid, but I'm concerned about the health hazard.
>Any comments?
>
>Barney
>
I use 1/8 inch fibre paper as a gasket to seal between body and
lid of the kiln. I fire to ^10.

sam - alias the cat lady
Melbourne, Ontario
SW Ontario CANADA
http://www.geocities.com/paris/3110
scuttell@odyssey.on.ca

"Thousands of years ago, cats were worshipped as gods.
Cats have never forgotten this."

Bobbi Bassett on thu 22 oct 98

Barney

I have never used blanket material to seal around the lid edge, but I do fire
with a piece of blanket material laying on top of the lid to reduce heat loss
and fire just a bit quicker. What it seems to do is give me a better firing
for the pieces on the top shelf. Good luck! It all seems to be trial and
error.

Bobbi in PA

Marty Anderson on sat 24 oct 98

Barney,

I use the fiber one would use to make a raku kiln to gasket the lid of my
Paragon 800. It works perfectly. I fire to ^6

Marty
-----Original Message-----
From: the cat lady
To: CLAYART@LSV.UKY.EDU
Date: Wednesday, October 21, 1998 12:05 PM
Subject: Re: Kiln blanket


----------------------------Original message----------------------------
At 09:45 AM 10/20/98 EDT, you wrote:
>----------------------------Original message----------------------------
>Hi,
>I'd like to reduce the heat loss from the lid of my Skutt 1027.
>I was thinking of using some kiln blanket material to seal around the
>edge of the lid, but I'm concerned about the health hazard.
>Any comments?
>
>Barney
>
I use 1/8 inch fibre paper as a gasket to seal between body and
lid of the kiln. I fire to ^10.

sam - alias the cat lady
Melbourne, Ontario
SW Ontario CANADA
http://www.geocities.com/paris/3110
scuttell@odyssey.on.ca

"Thousands of years ago, cats were worshipped as gods.
Cats have never forgotten this."

Margaret Carson on tue 27 oct 98

Instead of a kiln blanket, I have been using clay bricks placed to cover the
lid of my Skutt 1027-3 as I understood the greatest heat loss was from the
lid. Is this a foolish or harmful practice? I fire both bisque and to ^6
and was as interested in reducing my electric bills as containing the heat.

Thanks for any comments. Marge in Austin

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Gerard Carriere on wed 19 apr 00

------------------
kiln blankets
Some potter friends have started covering their electric kilns with blanket
covers especially around the top to speed up firing and save on power.
-Is this recommended?
-If so, what is best?
-What are the pros and cons?
What precautions to take with frequent handling?
Gerard =E0 No=EBlville, Ont. looking at Bear Lake where three swans were
chatting with my dog Finette.

Arnold Howard on thu 20 apr 00

Wrapping a kiln in a ceramic blanket would yield
negligible energy savings. I would be interested in
hearing from those who have tried it.

Arnold Howard

--- Gerard Carriere wrote:
> ----------------------------Original
> message----------------------------
> ------------------
> kiln blankets
> Some potter friends have started covering their
> electric kilns with blanket
> covers especially around the top to speed up firing
> and save on power.
> -Is this recommended?
> -If so, what is best?
> -What are the pros and cons?
> What precautions to take with frequent handling?
> Gerard ` Noklville, Ont. looking at Bear Lake where
> three swans were
> chatting with my dog Finette.
>

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Patricia Sannit on fri 21 apr 00

-I have a large oval Olympic kiln. I was having difficulty reaching
temperature in a reasonable amount of time until I started to cover the top
with a ceramic fiber blanket. My kiln now fires in what I consider a
reasonable amount of time. I tacked the blanket on top with nichrome wire
pins so as not to necessitate it's removal each firing, as it is friable.
It does also slow down the cooling of the kiln, but I like to think of that
as a good thing, rather than a nuisance. The caveat I have is that both my
oval lids have fine cracks down the middle. I have wondered if that was a
result of using the blanket, or perhaps just the nature of the lid. They
do undergo a fair amount of stress each time they are lifted. No science,
or control here, just anecdotal evidence. Patricia Sannit >
----------------------------Original message----------------------------
-> Wrapping a kiln in a ceramic blanket would yield
-> negligible energy savings. I would be interested in
-> hearing from those who have tried it.
->
-> Arnold Howard
->
-> --- Gerard Carriere wrote:
-> > ----------------------------Original
-> > message----------------------------
-> > ------------------
-> > kiln blankets
-> > Some potter friends have started covering their
-> > electric kilns with blanket
-> > covers especially around the top to speed up firing
-> > and save on power.
-> > -Is this recommended?
-> > -If so, what is best?
-> > -What are the pros and cons?
-> > What precautions to take with frequent handling?
-> > Gerard ` Noklville, Ont. looking at Bear Lake where
-> > three swans were
-> > chatting with my dog Finette.
-> >
->
-> __________________________________________________
-> Do You Yahoo!?
-> Send online invitations with Yahoo! Invites.
-> http://invites.yahoo.com

Tom Buck on fri 21 apr 00

Arnold & Gerard:
Makers of insulating firebrick (IFB) have software programs that
will calculate the heat loss from hot kilns, and also the "cold" wall
temperature under such condition. The heat transfer from a 1200 oC
interior to the outside is entirely predictable given the type of IFB, its
thickness, and the wrap-around of the kiln.
If you were to have 48 amperes flowing to the elements under a
voltage of 230 you'd be drawing 11+ kilowatts of electricity, which when
converted to heat units, namely joules, works out to 11,000 joules per
second, or 660,000 joules per minute, or almost 40 million joules per
hour. At Cone 6, more than half of this heat departs from the kiln as soon
as it is produced in the elements. What's left over heats up the ware to a
higher temperature.
Kilns will stall if the heat loss is equal to the the heat energy
produced by the elements.
The software will also allow one to calculate the "cold" wall
temperature given specific interior temperatures. In a typical octogonal
kiln, the cold wall will reach well above 100 oC (close to 200 oC in some
kiln designs) when the interior is at C6 (1220 oC).
To lower this cold wall temperature you could add another layer of
IFBs, or mineral wool (25-50 mm thick), or ceramic board (factory
compressed ceramic blanket), or ceramic blanket/"paper" itself. Given
suitable insulation the cold wall temperature can be lowered below 100 oC.
With a cooler cold wall, the heat transfer rate will be lowered
too, and there will be a savings in electricity used to get the kiln to
C6. However, the "payback" time may be two or more years, depending on the
particular setup and kiln use.
As for use of ceramic blanket as a wrap around the kiln, etc.,
this becomes questionable because of the extra hazard introduced once the
blanket has been fired and is therefore "friable". Fired blanket doesn't
withstand moving about, or being banged about, so it needs a cover and
special care.
Potters who do a lot of soak-firing at high cones should consider
extra outside insultion. But otherwise accept higher energy costs as part
of the basic operating costs, and so avoid spending extra capital dollars
for extra insulation.
Good pots. BFM. Peace. Tom B.

Tom Buck ) tel: 905-389-2339 (westend Lake Ontario,
province of Ontario, Canada). mailing address: 373 East 43rd Street,
Hamilton ON L8T 3E1 Canada

ferenc jakab on sat 22 apr 00

> Potters who do a lot of soak-firing at high cones should consider
> extra outside insultion. But otherwise accept higher energy costs as part
> of the basic operating costs, and so avoid spending extra capital dollars
> for extra insulation.
> Good pots. BFM. Peace. Tom B.
>
When I converted the electric kiln I was given to gas, I took the outer
layer apart and removed the vermiculite, (left the brick work in
place)replacing it with fibre blanket to 50mm thick (2"). Before this kiln
was over fired and destroyed as an electric kiln. I once measured the heat
given off by the stainless steel covering and it was 300 Deg C on top of the
kiln. Now it is 80 Deg C at 1150 C. Quite a savings in energy.
Feri.

Kristi Sloniger on sat 22 apr 00

------------------
I, too, use a kiln blanket for my electric kiln. I have an ancient Paragon =
A29b
that
I bought used. I was having trouble getting it up to temp, =5E6. I =
installed a
blanket
on the outside of the bottom and around the entire exterior casing. I also =
used
one on the top. This did the trick. My original top also split down the =
middle
-
completely=21 I purchased a new one and don't use the blanket on top of =
this
one. I thought it might have caused the crack in the top, but, I also have =
a
hairline crack down the middle of this one after a year in service.

Kristi Sloniger
Oak Park, IL

eden@sover.net on wed 26 apr 00

------------------
Hi Gerard and all,

Maybe this is an appropriate time to mention that I turned my L=26L into a
little silo, wrapped it in 2=22 kaowool, wrapped that in chickenwire,
trowelled on cement. (Of course the control panel is removed then
re-attached with longer screws.) So the kaowool is ON there. For the lid
I just use one or two extra old lids on top rather than try to use more
blanket for the obvious reason that it deteriorates so badly. But I use
the lid for drying stuff during the firing since it isn't too hot up there
and wouldn't want a blanket in the way. Now it would make sense to put a
bit of the blanket between two lids on top, just roll it up and put it in a
plastic bag between uses.

We have gone up and down on this list that it destroys the metal surface of
the kiln.....balderdash......I unwrapped my first kaowool skin which wasn't
put on so permanently and had been gradually deteriorating at the top of
the kiln, and the metal beneath was fine. This must have been after at
least 5 years.

Eleanora.......swans......nice=21



=3E----------------------------Original message----------------------------
=3E------------------
=3Ekiln blankets
=3ESome potter friends have started covering their electric kilns with =
blanket
=3Ecovers especially around the top to speed up firing and save on power.
=3E-Is this recommended?
=3E-If so, what is best?
=3E-What are the pros and cons?
=3EWhat precautions to take with frequent handling?
=3EGerard =E0 No=EBlville, Ont. looking at Bear Lake where three swans were
=3Echatting with my dog Finette.
=3E

Eleanora Eden 802 869-2003
Paradise Hill
Bellows Falls, VT 05101 eden=40sover.net