Barney Adams on tue 1 dec 98
Well I attempted the pit firing over the holidays and
didn't seem to have much luck. The burn/smoldering of
the saw dust was incomplete. I'm wondering if the sawdust
was packed too hard. It wasn't a total loss as I put the
pots under a pile of wood burned down too coals and then
smothered the red hot pots with the sawdust. Got some nice
effects.
Barney
lpskeen on wed 2 dec 98
Barney Adams wrote:
>
> ----------------------------Original message----------------------------
> Well I attempted the pit firing over the holidays and
> didn't seem to have much luck. The burn/smoldering of
> the saw dust was incomplete. I'm wondering if the sawdust
> was packed too hard. It wasn't a total loss as I put the
> pots under a pile of wood burned down too coals and then
> smothered the red hot pots with the sawdust. Got some nice
> effects.
>
> Barney
Barney,
Our experience here has been that the photos in the PMI article are
misleading. Fire doesn't want to burn down, it wants to burn UP,
thus, it is hard to get the sawdust to burn unless you light it from the
bottom of your can. You have to let it burn, smolder awhile, stir it up
some more, burn some more, etc.
--
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
Claudia O Driscoll on wed 2 dec 98
Barney,
It is hard to know what went 'wrong' with the pit firing, but if you packed
the sawdust too tightly, you might not have allowed room for the smoke to
move about. I have gradually moved from using a lot of sawdust to using
only a small amount, along with sticks, leaves, and other combustibles.
You can never know just what will happen, though...that is part of the
MAGIC.
claudia
Pat Porter on thu 3 dec 98
Hi Barney, Claudia et al.
I an using Laguna's R2 red earthenware clay. Since my pieces are not
functional, I routinely finish with a polyutherene marine spar (satin
finish) It enhances the color contrast and makes the earthenware water
tight if the piece is a vase.
A little trick that I have developed is what I call "hamster fired" pieces.
You use hamster litter shavings, newspaper, and a galvinized bucket with a
multitude of holes drilled bottom and sides as well as a broken clay shelf
for a lid. Make a ring of newspaper on the bottom of the pail and place a
handful of wood chips on top of that. Begin placing pieces and shavings.
An occasional loose ball of newspaper would help - but use mostly wood
chips. Cover this pottery lasagna with a final layer of wood chips and
cover. Light from the bottom and "cook until done". On a dull day, it will
take about 45 min. I like doing the fuming this way because it is quick,
portable (I can smoke the stuff in my fireplace that has glass doors) and
gives a natural smoke path design. The secret is using the hampster litter
because it does not pack and allows for air circulation. The smoke patterns
do the neatest things! Try it! I'm also going to try it on a clay body
that has been fired to /\ 10 unglazed.
Pat Porter
kitties@pcisys.net
Aurora Colorado
lpskeen on thu 3 dec 98
Barney Adams wrote:
>
> ----------------------------Original message----------------------------
> Well I attempted the pit firing over the holidays and
> didn't seem to have much luck. The burn/smoldering of
> the saw dust was incomplete. I'm wondering if the sawdust
> was packed too hard. It wasn't a total loss as I put the
> pots under a pile of wood burned down too coals and then
> smothered the red hot pots with the sawdust. Got some nice
> effects.
>
> Barney
Barney,
Our experience here has been that the photos in the PMI article are
misleading. Fire doesn't want to burn down, it wants to burn UP,
thus, it is hard to get the sawdust to burn unless you light it from the
bottom of your can. You have to let it burn, smolder awhile, stir it up
some more, burn some more, etc.
--
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
Earl Brunner on thu 3 dec 98
We did some sawdust firing when I was at Utah State in the 70's. We burned
from the top down in a 55 gal drum that had a few holes punched in the sides
(with a claw hammer or screwdriver), placed a screen over the top to catch
flying embers. The holes in the sides where the key I think to getting the
sawdust to burn from the top down. Worked great, don't think it would work
very well in/on the ground for the reasons Lisa listed. Ours got very hot,
but without actual flame, just sorta smoldered down through the pots and
sawdust.
Earl Brunner
lpskeen wrote:
> ----------------------------Original message----------------------------
> Barney Adams wrote:
> >
> > ----------------------------Original message----------------------------
> > Well I attempted the pit firing over the holidays and
> > didn't seem to have much luck. The burn/smoldering of
> > the saw dust was incomplete. I'm wondering if the sawdust
> > was packed too hard. It wasn't a total loss as I put the
> > pots under a pile of wood burned down too coals and then
> > smothered the red hot pots with the sawdust. Got some nice
> > effects.
> >
> > Barney
>
> Barney,
> Our experience here has been that the photos in the PMI article are
> misleading. Fire doesn't want to burn down, it wants to burn UP,
> thus, it is hard to get the sawdust to burn unless you light it from the
> bottom of your can. You have to let it burn, smolder awhile, stir it up
> some more, burn some more, etc.
> --
> 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
Vince Pitelka on thu 3 dec 98
>Our experience here has been that the photos in the PMI article are
>misleading. Fire doesn't want to burn down, it wants to burn UP,
>thus, it is hard to get the sawdust to burn unless you light it from the
>bottom of your can. You have to let it burn, smolder awhile, stir it up
>some more, burn some more, etc.
My experience has been just the opposite. I have always gotten the best
results by lighting from the top, and then leaving the thing completely
alone while the sawdust burns down slowly from the top. This has never
failed to work extremely well. There are several important considerations.
If your sawdust is too dry, too coarse and/or too loose, it will burn too
fast, possibly cracking your wares. If it is too wet, too fine, and/or
packet too tightly, or if you have not allowed adequate air holes around the
outside and at the top, it will go out during the firing. I use the term
firing here, but of course what we are talking about is a sawdust smoking,
which is not a true firing process at all, since it does not achieve
adequate temperature for even minimal sintering. Always bisque-fire the
pots first.
I have achieved the best results with a mix of fine and coarse sawdust, in a
tightly-stacked brick enclosure or an old drum with holes drilled in the
outside (draw a 10" grid of lines on the outside of the drum, and drill a
3/8" hole everywhere the lines intersect.). If your sawdust is extremely
dry, sprinkle it with just a bit of water, mix it up, sprinkle it a bit, mix
some more. Start with a bed of sawdust, some pots, more sawdust, more pots.
As you place the pots remember that they will end up piled on top of one
another as the sawdust burns away. When filling the brick enclosure or
drum, leave at least eight or ten inches empty at the top. Place a layer of
crumpled newspaper over the top of the sawdust. Light the newspaper and let
it flame up completely until it in turn ignites the sawdust. Place a steel
plate or kiln shelves over the top of the enclosure, leaving a very small
crack to insure the continued movement of air through the sawdust.
Depending on the kind of sawdust you have, and the humidity in the
atmosphere, you may or may not have to dampen the sawdust. Do some
experiments to see how it burns before ever stacking it with your wares.
Under ideal conditions, it should take from 8 to 24 hours for the sawdust to
burn down completely.
Good luck -
- Vince
Vince Pitelka - vpitelka@DeKalb.net
Home 615/597-5376, work 615/597-6801, fax 615/597-6803
Appalachian Center for Crafts
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
Barney Adams on fri 4 dec 98
Hi,
What Vince describes below is how I tried to do the firing.
I had a 20 gal galvanized trash can. The saw dust was mixed
coarse/fine sawdust and dry. The airholes may not have been enough
and possibly not regular around the can. I just know that several of
the pots got blackened but the copper carb/borax was still just
a green powder.
Barney
>
> ----------------------------Original message----------------------------
> >Our experience here has been that the photos in the PMI article are
> >misleading. Fire doesn't want to burn down, it wants to burn UP,
> >thus, it is hard to get the sawdust to burn unless you light it from the
> >bottom of your can. You have to let it burn, smolder awhile, stir it up
> >some more, burn some more, etc.
>
> My experience has been just the opposite. I have always gotten the best
> results by lighting from the top, and then leaving the thing completely
> alone while the sawdust burns down slowly from the top. This has never
> failed to work extremely well. There are several important considerations.
> If your sawdust is too dry, too coarse and/or too loose, it will burn too
> fast, possibly cracking your wares. If it is too wet, too fine, and/or
> packet too tightly, or if you have not allowed adequate air holes around the
> outside and at the top, it will go out during the firing. I use the term
> firing here, but of course what we are talking about is a sawdust smoking,
> which is not a true firing process at all, since it does not achieve
> adequate temperature for even minimal sintering. Always bisque-fire the
> pots first.
>
> I have achieved the best results with a mix of fine and coarse sawdust, in a
> tightly-stacked brick enclosure or an old drum with holes drilled in the
> outside (draw a 10" grid of lines on the outside of the drum, and drill a
> 3/8" hole everywhere the lines intersect.). If your sawdust is extremely
> dry, sprinkle it with just a bit of water, mix it up, sprinkle it a bit, mix
> some more. Start with a bed of sawdust, some pots, more sawdust, more pots.
> As you place the pots remember that they will end up piled on top of one
> another as the sawdust burns away. When filling the brick enclosure or
> drum, leave at least eight or ten inches empty at the top. Place a layer of
> crumpled newspaper over the top of the sawdust. Light the newspaper and let
> it flame up completely until it in turn ignites the sawdust. Place a steel
> plate or kiln shelves over the top of the enclosure, leaving a very small
> crack to insure the continued movement of air through the sawdust.
> Depending on the kind of sawdust you have, and the humidity in the
> atmosphere, you may or may not have to dampen the sawdust. Do some
> experiments to see how it burns before ever stacking it with your wares.
> Under ideal conditions, it should take from 8 to 24 hours for the sawdust to
> burn down completely.
> Good luck -
> - Vince
>
> Vince Pitelka - vpitelka@DeKalb.net
> Home 615/597-5376, work 615/597-6801, fax 615/597-6803
> Appalachian Center for Crafts
> Tennessee Technological University
> 1560 Craft Center Drive, Smithville TN 37166
>
Bob and Hulda on sat 5 dec 98
Dear Barney,
The purpose of a sawdust firing is to blacken pots
and will not give colour from copper carbonate,it will give slight flashing
from copper sulphate.there is a world of difference between the type of
firing you are describing and a pitfire.I pitfire using timber and peat
which I keep heaping on to ensure that the pots will be completely covered
with a layer of red hot embers which I leave smouldering over-night,first
thing in the morning I uncover the pit and pile it full of hay[bought from a
neighbour] and recover,this gives the blacking to areas of the pots.I just
leave the pit until I have the time to do all the cleaning.Any pots I am
unhappy with simply get put into the next firing.I guess the main thing
about pit firing is simply "What you get is what you get"some pots send your
spirit soaring others bring you back down with a thump but hang on in there
because the ride is GREAT!!!
Regards,
Bob Hollis
sandra m benscoter on sun 6 dec 98
Hi!
I saw dust fire in a drum also. Make sure the holes are in the top,
bottom, and middle of the drum to insure sufficient air flow. Just toss
in the saw dust, don't pack tightly. I use a piece of metal over the top
(not a screen). I start the fire on top with newspapers and when the saw
dust starts a good burn I cover and don't touch it until the saw dust has
burned/smoldered down to the bottom. Always good results with minimal
amount of work!
Have fun trying again!
Sande
sbenscoter@juno.com
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