Kevin P. O'Hara on sat 29 mar 97
Fossil fuel fiber kiln
Hello again,
Well, my fertile imagination is being creative again. I was wondering, has
anyone built a down draft fiber kiln that was fired with either wood or coal
-- and or both? Would the burning of (hard) coal adversely affect the fiber
walls?
Kevin P. O'Hara
Mudslinger Pottery
mudslinger@iquest.net
www.iquest.net/~mudslinger
koratpot@korat.loxinfo.co.th on mon 31 mar 97
I have tried using a fiber door on a wood burning kiln, and sticking
scraps of fiber to the roof of the kiln to see what would happen.
Total destruction in 2-3 firings. that's what happened.
Nikom
koratpot@korat.loxinfo.co.th
----------------------------Original message----------------------------
< I was wondering, has
anyone built a down draft fiber kiln that was fired with either wood or coal
-- and or both? >
Lawrence Ewing on wed 2 apr 97
Hi Kevin,
We (i.e. Ceramics Dept., School of Art, Otago Polytechnic, Dunedin, New
Zealand) are currently building a small anagamma-type wood kiln with a
burri firebox. The main chamber will have a removeable 'top-hat' arched
roof built from fibre attached to steel netting. My colleague who has
lost count of the number of kilns he has built assures me that the fibre
will survive if it is stack bonded i.e. the end grain of the fibre pieces
will be exposed to the internal atmosphere of the kiln and, although it
will be fluxed by the flyash during firing it should remain intact. I
hope he is right!!!! Has anyone else used this technique for building
solid fuel kilns?
Lawrence Ewing
lewing@clear.net.nz
21 Slant St
Careys Bay
Dunedin
NEW ZEALAND
ph (03) 472 8801
Author of MATRIX Glaze Calculation Software for Macintosh
Kevin P. O'Hara on wed 2 apr 97
Thanks for your reply. I called an engineer working for a company that
makes ceramic fiber in Canada the other day and he said that in the low
2000Fs, the potassium in wood turns to a flux and melts the fiber. He said
that coal would not hurt the fiber, it is just that the sulfur can corrode
the surface that it is attached to. I am interested in coal and fiber
because it seems to me that, togather they are the most economical to use.
Fiber is very efficient and coal burns very hot and is relatively
inexpensive and low in sulfur where I live.
I was wondering, will it take less than 10 days to fire if you are using
fiber? How many people does it take to fire something like that? Will you
be able to use less wood to fire this kiln since it does not have to heat up
the kiln itself? If I ever find myself in the orient, I am going to have to
tour the different pottery sites that fire anagamma kilns. It seems the
world is getting smaller every day.
Kevin P. O'Hara
Indianapolis, IN
mudslinger @iquest.net
http://www.iquest.net/~mudslinger
----------
From: CLAYART
To: Multiple recipients of list CLAYART
Subject: Re: Fossil fuel fiber kiln
Date: Wednesday, April 02, 1997 9:11AM
----------------------------Original message----------------------------
Hi Kevin,
We (i.e. Ceramics Dept., School of Art, Otago Polytechnic, Dunedin, New
Zealand) are currently building a small anagamma-type wood kiln with a
burri firebox. The main chamber will have a removeable 'top-hat' arched
roof built from fibre attached to steel netting. My colleague who has
lost count of the number of kilns he has built assures me that the fibre
will survive if it is stack bonded i.e. the end grain of the fibre pieces
will be exposed to the internal atmosphere of the kiln and, although it
will be fluxed by the flyash during firing it should remain intact. I
hope he is right!!!! Has anyone else used this technique for building
solid fuel kilns?
Lawrence Ewing
lewing@clear.net.nz
21 Slant St
Careys Bay
Dunedin
NEW ZEALAND
ph (03) 472 8801
Author of MATRIX Glaze Calculation Software for Macintosh
stevemills on thu 3 apr 97
In message <199703310106.IAA26681@korat.loxinfo.co.th>,
koratpot@korat.loxinfo.co.th writes
>----------------------------Original message----------------------------
>I have tried using a fiber door on a wood burning kiln, and sticking
>scraps of fiber to the roof of the kiln to see what would happen.
>Total destruction in 2-3 firings. that's what happened.
>Nikom
>koratpot@korat.loxinfo.co.th
>----------------------------Original message----------------------------
>< I was wondering, has
>anyone built a down draft fiber kiln that was fired with either wood or coal
> -- and or both? >
Dear Nikom,
In the U.K. we use Carborundum's Rigidiser (W), which is a colloidal
silica, to harden the surface of gas fired raku kilns. This prevents
them degrading. Maybe this will help in a wood-firing situation.
Good luck. Steve.
--
stevemills
Sheila Clennell on fri 4 apr 97
>----------------------------Original message----------------------------
>Hi Kevin,
>
>We (i.e. Ceramics Dept., School of Art, Otago Polytechnic, Dunedin, New
>Zealand) are currently building a small anagamma-type wood kiln with a
>burri firebox. The main chamber will have a removeable 'top-hat' arched
>roof built from fibre attached to steel netting. My colleague who has
>lost count of the number of kilns he has built assures me that the fibre
>will survive if it is stack bonded i.e. the end grain of the fibre pieces
>will be exposed to the internal atmosphere of the kiln and, although it
>will be fluxed by the flyash during firing it should remain intact. I
>hope he is right!!!! Has anyone else used this technique for building
>solid fuel kilns?
>
>
>
>Lawrence Ewing
>lewing@clear.net.nz
>21 Slant St
>Careys Bay
>Dunedin
>NEW ZEALAND
>ph (03) 472 8801
>Author of MATRIX Glaze Calculation Software for Macintosh
Leonard Smith on mon 7 apr 97
Steve Harrison Built a large bourry boxed wood fired fibre kiln in 1979 and
fired it extensively for two years. Steve used very high alumina board
called Safil on the area above the throat arch. The case was a stainless
steel box with a swinging door. The firebox and arch were made of ri26 and
from memory fired to cone 10 in 12hrs using a pile of hardwood 3'x3'x3', it
was very efficient. This kiln was the precuser of the extended throat
Bourry box he has made famous which was followed by the "No-bull-i-gama"
which appears in the latest Pottery in Australia (Vol 36 No1).
From memory he has published plans for this kiln in "The Handbook for
Australian Potters"
Best wishes
Leo
---------------------------------------------------------------------------
Leonard Smith ARCADIA STUDIOS Email: leosmith@wr.com.au
10 Marrakesh Place
smithl@ozemail.com.au
Arcadia, 2159, NSW, Australia. Phone + 61 2 9653 2507
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
http://www.ozemail.com.au/~smithl/
---------------------------------------------------------------------------
Sheila Clennell on mon 7 apr 97
>----------------------------Original message----------------------------
>Hi Kevin,
>
>We (i.e. Ceramics Dept., School of Art, Otago Polytechnic, Dunedin, New
>Zealand) are currently building a small anagamma-type wood kiln with a
>burri firebox. The main chamber will have a removeable 'top-hat' arched
>roof built from fibre attached to steel netting. My colleague who has
>lost count of the number of kilns he has built assures me that the fibre
>will survive if it is stack bonded i.e. the end grain of the fibre pieces
>will be exposed to the internal atmosphere of the kiln and, although it
>will be fluxed by the flyash during firing it should remain intact. I
>hope he is right!!!! Has anyone else used this technique for building
>solid fuel kilns?
>
>
>
>Lawrence Ewing
>lewing@clear.net.nz
>21 Slant St
>Careys Bay
>Dunedin
>NEW ZEALAND
>ph (03) 472 8801
>Author of MATRIX Glaze Calculation Software for Macintosh
Dear Lawrence: I thought I was the only one of there considering an
ananagama wood kiln made from fiber. The stack bonded fiber sounds like a
great idea. If you were to spray the fiber with ITC 100 it would give it a
very hard and durable surface. It would give you a very efficient
woodkiln. You can see all the controvsy about ITC products by looking at
the discussion on elements in Clayart. There have also been several
listings of potters using ITC products for salt/soda firings in softbrick
and fiber kilns. If it can withstand soda vapours I think it will minimize
ash buildup as well. The benefits of the fiber woodkiln is that you can
have a long firing or if the desire for sleep overcomes you then give the
kiln hell!
Sheila and I are firing our woodkiln tomorrow. The walls are coated with
ITC 100, as are the kiln shelves, and we have fiber coated squares in the
fire box to give it the true test. The grates are also coated with ITC 213
because we have been burning them up at a pretty steady pace. Give us a
note on Tuesday and I'll give you the low down.
Long may your chimney smoke!
Tony Clennell
Gleason Brook Pottery,
Box l0, RR#2,
Wiarton, Ontario
NOH 2TO
Canada
Sylvia See on tue 8 apr 97
Thanks Tony and Lawrence;
Thanks a bunch for the question and the answer. I am building a kiln of
clay wrapped inside with fiber and was wondering how to fasten the fiber
and how to treat it and so will get some of this ITC stuff right away,
sounds great.
I'm attempting making a kiln shell that can be setup on firebrick base
that will go to cone 10 or as close to that as I can get. Making a paper
mache mold over chicken wire wrapped around the outside of a 7 cu ft
electric kiln on wheel base. The base and outside measurements hopefully
will give me the size I need for my castles. Then going to apply cone 10
raku clay, with coils from my pugmill. Have no idea if its going to work,
and am using a downdraft drawing of a beehive kiln from one of my old
pottery books as a model. I need it portable so I can setup where I Raku
near my propane bottles. Hopefully I will be able to decorate the shell and
leave it in the yard as an ornamental whatever, and just setup the base
each time I use it. We're hoping by firing the shell slowly the first time
it will burnout the paper mache and take the shell as high as I can without
cracking. Does anyone out there think it MIGHT work? To die for a place
and money to build one of brick, but in the meantime, giving it a shot with
this.
Sylvia See Claresholm Alta sylviac@telusplanet.net
I really like my bifocals
My dentures fit me fine
My hearing aid works perfect
But Lord I miss my mind!!!!
stevemills on thu 10 apr 97
In message <97Apr7.123551-0600_mdt.153659-6114+296@mail.telusplanet.net>
, Sylvia See writes
>----------------------------Original message----------------------------
>Thanks Tony and Lawrence;
> Thanks a bunch for the question and the answer. I am building a kiln of
>clay wrapped inside with fiber and was wondering how to fasten the fiber
>and how to treat it and so will get some of this ITC stuff right away,
>sounds great.
> I'm attempting making a kiln shell that can be setup on firebrick base
>that will go to cone 10 or as close to that as I can get. Making a paper
>mache mold over chicken wire wrapped around the outside of a 7 cu ft
>electric kiln on wheel base. The base and outside measurements hopefully
>will give me the size I need for my castles. Then going to apply cone 10
>raku clay, with coils from my pugmill. Have no idea if its going to work,
>and am using a downdraft drawing of a beehive kiln from one of my old
>pottery books as a model. I need it portable so I can setup where I Raku
>near my propane bottles. Hopefully I will be able to decorate the shell and
>leave it in the yard as an ornamental whatever, and just setup the base
>each time I use it. We're hoping by firing the shell slowly the first time
>it will burnout the paper mache and take the shell as high as I can without
>cracking. Does anyone out there think it MIGHT work? To die for a place
>and money to build one of brick, but in the meantime, giving it a shot with
>this.
> Sylvia See Claresholm Alta sylviac@telusplanet.net
>I really like my bifocals
>My dentures fit me fine
>My hearing aid works perfect
>But Lord I miss my mind!!!!
Dear Sylvia,
For several years now we have been building simple (but very effective)
human length anagama kilns using a technique which might be useful to
you. The basic frame is made out of hazel ribs interwoven with basket
makers reed or withies. All the materials are cut and used within days
to retain suppleness. We then cover the frame with newspaper overlaid
with a 3 to 4 inch layer of scrap stoneware (2 parts), sand(1part), and
chopped straw (1 part) mixed with water to a stiffish consistency (with
our feet!!!). The whole thing is dried out immediately, but SLOWLY with
a slow fire so that inside and out dry more or less at the same rate. At
the end of the drying period the woodwork burns away leaving us with a
pretty strong structure. With a couple of these we have then built a
serious sized fire around the outside to harden off the exterior. This
technique is very similar to that used for building ground ovens. We get
our kilns to cone 7 plus and are aiming higher.
The important thing for your structure would be to include chopped straw
in the mix and daub rather than coil. The former helps to bind the
mixture together, and daubing removes the need to "work" the inside of a
coiled piece, (difficult over a former)
Good luck
Steve
"Potters of the world ignite"
--
Steve Mills
@Bath Potters Supplies
Dorset Close
Bath
BA2 3RF
UK
Tel:(44) (0)1225 337046
Fax:(44) (0)1225 462712
Sylvia See on fri 11 apr 97
Thankyou Steve;
I appreciate the info on applying the clay on daubs instead of coils. This
is great. Now I don't have to change the clay in my pugmill, which is a
blankety-blank to clean out after. The gasket on the venco pugmill is a son
of a gun after cleaning. Mine stuck tight and was totally wrecked after the
first cleanup. Anyone with suggestions for making a new tight fitting
gasket for a venco pugmill?? I used some red goop, but air still leaks in
and makes hard clay down the side of the coils extruded and burns me up.
Interesting about the straw. That should be really easy for me to find
here in ranching country, but what does it do. Just curious, not doubting.
Paper mache cover 1/2 done and slowly getting there. Found out it is much
easier to make the paper mache as pulp using the my third hand, the trusty
electric drill and trowelling instead of the backbreaking process of dipped
strips. Man, I had no idea paper mache stunk so much. Starting to take
shape, and if this works should have a really good sized kiln for
reduction, (for my needs). I also put cloth strips over the chicken wire
before applying the paper mache, so hopefully, the mold should lift off
without having to burn the wire frame as well. Just a little doubtful worry
on my part, in case I need to try it again.Hee hee.
Sylvia See Claresholm, Alberta sylviac@telusplanet.net
The golden years have come at last, I cannot see, I cannot pee,
I cannot chew, I cannot screw. My memory shrinks, my hearing stinks.
No sense of smell, I look like hell. My body drooping, got trouble pooping.
The golden years have come at last, The golden years can kiss my Ass.
Peter Tomich on sat 12 apr 97
Well, it worked!
Sylvia, don't forget about shrinkage. I think if you fire over
the wire you will have some trouble. My kiln is set over a hole in the
ground and I made the kiln wall about 4 inches outside the hole. Good
thing because it shrank about 4 inches all around and it just made it. I
started by lighting a small fire with a few leaves in the side firing
chamber. The draw was good, the smoke went out the top of the kiln.
The second firing chamber wouldn't light, and I kept trying throughout
the evening, but it wouldn't go. I used it to add wood to the center
area. There was very little heat escaping from this chamber.
I felt it would take forever to get the kiln going, so I added wood to
the center chamber. I fired it as slowly as I could, everytime the
flames went too high a little piece would fly off, but there are no
holes in the kiln. I was worried that the whole thing would go. There
is a crack that runs from top to bottom, but it hasn't hurt it yet.
Then after about 2 hours the clay spitting stopped and I could raise the
temperature without worrying. I got it full of logs and kept adding
tinder and the flames went up about ten feet for a couple of hours then
I let it slow. After 5 hours I had about 6 inches of coals with shards
of 4 pots that didn't make it and the brave 2 who went in there green
and came out whole and bisqued. I took out the pots with a stick and put
them in a pot of dry leaves and partially shut the top to get more smoke
on them. The kiln still needs firing. I am happy with the firing, but
I wasn't expecting to have to build a fire on the outside of the kiln
which is what I will have to do next (It is still pretty powdery even
though it was pretty hot, it wasn't hot enough). I pushed the pots in
through my side firing chambers and the pots that made it were inside or
on top of the pots that didn't. I will use shards to shield my pots
next time. I will probably bisque first, but who knows. Would I do this
again? Hopefully I won't have to! Preparing the clay was a pain in the
butt. Also, I found I didn't like working so low to the ground (my back
complained). I loved working large in coils. I will probably make me
some large coil pots soon. If I do this again I want help. In Nigrosh's
book it seems that they fired it up right away after throwing it
together, but I constructed it over several days and the parts that
didn't spit were the dryest parts, so I would let the whole thing dry
next time.
I think I'll build it in one day with friends and then come back a week
later and fire it.
Good luck on yours, Sylvia. Love, Sam in Hawaii
stevemills on tue 15 apr 97
In message <97Apr10.084841-0600_mdt.268088-10618+25@mail.telusplanet.net
>, Sylvia See writes
>----------------------------Original message----------------------------
> Interesting about the straw. That should be really easy for me to find
>here in ranching country, but what does it do. Just curious, not doubting.
It helps to knit the daub together, and when fired out leaves an open
matrix which helps insulation (that's my theory anyway!) as you're in
ranching country you could (if you feel like it) add some cattle dung to
the mix, it makes it suprisingly strong. This is what used to be used on
the outside of wattle and daub houses
Steve
--
Steve Mills
@Bath Potters Supplies
Dorset Close
Bath
BA2 3RF
UK
Tel:(44) (0)1225 337046
Fax:(44) (0)1225 462712
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