Bonnie Staffel on fri 6 jan 06
Dear Philip,
I can only relate that which is my own experience in such non-kiln
firing processes. I categorize them mainly as Smoke Firing, Sawdust
Firing, Trash Can Firing and Pit Firing. It sounds like you were
combining the two middle firings, but not accomplishing either one
because of some basic errors in planning, IMO. If I am doing a Sawdust
Firing, I would use some wood as shavings, rather than sawdust, and I
would also fill the entire slotted container with the shavings
surrounding the pot, allowing it to fire from the top down, covering it
after it is smoldering well. That will give you fun markings, mostly
black, white and gray. I have also used copper in this firing for some
effects, but not for reds. The heat produced in this firing is not hot
enough to fume the salt, IMO and would not be a good idea to add to this
mix. This firing takes all day and maybe into the next, depending upon
the shavings material.
Next, I will explain Trash Can Firing which I have been using a lot for
the past several years with some success as I would like the pit fire
effects without the hole in the ground. Here I would have a trash can
liberally cut with slashes on the bottom and sides. The work should be
put on a couple of bricks, then add six or eight inches of Pet Litter,
sprinkle with copper and salt, place pots on the Pet Litter, add small
kindling around the pots, gradually filling the can with a little more
kindling no larger than 1" wide to the top, interspersed with some
crumpled paper. I squirt some charcoal lighter fluid over the top,
light it and let it blaze. I let this burn furiously, hopefully with a
good wind to fan the flames, then cover with the lid partially, only to
force some heat down. When the fire has gone down to hot coals in the
bottom then the lid is closed up to about 1" to allow air circulation.
If the can smokes, then open the lid somewhat until no smoke appears.
This process takes about 2 hours and you really need a hot fire.
Different kinds of kindling will produce good or poor effects.
Hardwoods are the best but Oak in my last firing did not burn furiously
enough. This will take experimenting with to find the right source of
wood.
With this last type of firing, you can then hope for copper reds and
other colors, the salt fuming to give the salmon colors and not creating
any deterioration to the pot. In comparison, the sawdust firing is not
hot enough to do much more than to produce carbon in the clay body for
the blacks. I have also used some clay resist to these pots for
patterning of my choice. The resist can then be washed off leaving the
pattern against the gray or black background.
When you mention "lumber" for your wood, it sounds like the pieces are
too big and thick. Fine kindling is so much better for a furious fire
and packed tight enough to generate a lot of heat inside the can. I
might also caution you not to fire this way if you have cold weather.
That invites cracking and stress to the pot when the bottoms are hot and
the tops are very cold.
I get very itchy to do one of these firings during the winter, so am
thinking of placing one of my pots in my electric kiln, put four pieces
of crumpled paper around it, and light the paper. I am thinking that I
could have the lid partially propped open so no flames or ash fly out of
the kiln and also keep the pot from cracking being in the cold garage.
Is this a nutty idea or does it sound like a workable one? Otherwise,
could look for a big used metal potato chip can, poke some holes in it
and fire that outside. It only takes about two or three minutes to burn
the paper up. But the effects are most times great.
Warm regards,
Bonnie Staffel
http://webpages.charter.net/bstaffel/
DVD Throwing with Coils and Slabs
DVD Beginning Processes
Charter Member Potters Council
>What I did on my winter break...........
>1) Holes in the drum are good. More holes are better. One website I
read suggested 24 of them at 1/2 inch around the bottom area of the
drum. I did that, then added 6 more, and I think that, had I done
another set of 12 or so about 1/3 of the way up the drum I would have
fared better.
2) Fuel is good. Too much fuel isn't. I put a layer of sawdust, the
pots wrapped in wet cotton material soaked in salt water with a variety
of oxides then put on them, then some heating pellets, a bunch of a
friend's junk mail (envelopes don't burn well unless you crumple them,
btw, duh) both layers I'd added salt to and soaked with starter fluid,
then I put in the wood itself. Oh, and around and above the pots I also
put some of those compressed sawdust logs. Finally I put more pellets,
paper, and lighter fluid.
The wood caught great, the paper formed a heat barrier, I think.
3) If you have a layer that isn't burning, mix it up a bit so that it
will catch instead of forming an insulating blanket. (See the envelopes
above.)
4) Removing the lid of the drum in order to get things going again
works. The fire had almost completely died without reaching the sawdust
when I removed an inner cover made out of a trashcan lid. The fire then
started heating up, finally getting very hot. This was 2 days after
starting, btw.
5) You can always refire.
So I will. Probably next weekend. And this time no letters, more
lumber, and more air holes.
Still, I like some of what I got. As soon as I can get these photos
transferred (probably next week) I'll post them.
>Philip Tuley
2ley on sun 8 jan 06
Bonnie,
Wow, what a great post. I had picked up my ideas from another artist's
website, he uses sawdust in the bottom as opposed to cat litter. I am going
to try your method, hopefully today. It gets cool here, but not really
"cold", so I should be OK.
The paper thing sounds interesting. Have you considered a small (20
gallon) trash can?
Thanks again,
Philip
From: "Bonnie Staffel"
> Dear Philip,
>
> I can only relate that which is my own experience in such non-kiln
> firing processes. I categorize them mainly as Smoke Firing, Sawdust
> Firing, Trash Can Firing and Pit Firing. It sounds like you were
> combining the two middle firings, but not accomplishing either one
> because of some basic errors in planning, IMO. If I am doing a Sawdust
> Firing, I would use some wood as shavings, rather than sawdust, and I
> would also fill the entire slotted container with the shavings
> surrounding the pot, allowing it to fire from the top down, covering it
> after it is smoldering well. That will give you fun markings, mostly
> black, white and gray. I have also used copper in this firing for some
> effects, but not for reds. The heat produced in this firing is not hot
> enough to fume the salt, IMO and would not be a good idea to add to this
> mix. This firing takes all day and maybe into the next, depending upon
> the shavings material.
>
> Next, I will explain Trash Can Firing which I have been using a lot for
> the past several years with some success as I would like the pit fire
> effects without the hole in the ground. Here I would have a trash can
> liberally cut with slashes on the bottom and sides. The work should be
> put on a couple of bricks, then add six or eight inches of Pet Litter,
> sprinkle with copper and salt, place pots on the Pet Litter, add small
> kindling around the pots, gradually filling the can with a little more
> kindling no larger than 1" wide to the top, interspersed with some
> crumpled paper. I squirt some charcoal lighter fluid over the top,
> light it and let it blaze. I let this burn furiously, hopefully with a
> good wind to fan the flames, then cover with the lid partially, only to
> force some heat down. When the fire has gone down to hot coals in the
> bottom then the lid is closed up to about 1" to allow air circulation.
> If the can smokes, then open the lid somewhat until no smoke appears.
> This process takes about 2 hours and you really need a hot fire.
> Different kinds of kindling will produce good or poor effects.
> Hardwoods are the best but Oak in my last firing did not burn furiously
> enough. This will take experimenting with to find the right source of
> wood.
>
> With this last type of firing, you can then hope for copper reds and
> other colors, the salt fuming to give the salmon colors and not creating
> any deterioration to the pot. In comparison, the sawdust firing is not
> hot enough to do much more than to produce carbon in the clay body for
> the blacks. I have also used some clay resist to these pots for
> patterning of my choice. The resist can then be washed off leaving the
> pattern against the gray or black background.
>
> When you mention "lumber" for your wood, it sounds like the pieces are
> too big and thick. Fine kindling is so much better for a furious fire
> and packed tight enough to generate a lot of heat inside the can. I
> might also caution you not to fire this way if you have cold weather.
> That invites cracking and stress to the pot when the bottoms are hot and
> the tops are very cold.
>
> I get very itchy to do one of these firings during the winter, so am
> thinking of placing one of my pots in my electric kiln, put four pieces
> of crumpled paper around it, and light the paper. I am thinking that I
> could have the lid partially propped open so no flames or ash fly out of
> the kiln and also keep the pot from cracking being in the cold garage.
> Is this a nutty idea or does it sound like a workable one? Otherwise,
> could look for a big used metal potato chip can, poke some holes in it
> and fire that outside. It only takes about two or three minutes to burn
> the paper up. But the effects are most times great.
steve graber on sun 8 jan 06
this is a good time to post the fact that more neighborhoods then one might expect have a local wood shop guy. might be the cabnet maker, custom fireplace or sterio equipment, whatever.
find your local guy for good quality saw dust in coarse, fine, extra fine grades. pine, hardwoods, etc.
i got some 50 bags of sawdust over a few months to be used for compost in my garden, and also for various sawdust fires. i also have a batch of sawdust clay using the good old local guys.
cost: 2 basic mugs.
see ya
steve
2ley <2ley@MCHSI.COM> wrote: Bonnie,
Wow, what a great post. I had picked up my ideas from another artist's
website, he uses sawdust in the bottom as opposed to cat litter. I am going
to try your method, hopefully today. It gets cool here, but not really
"cold", so I should be OK.
The paper thing sounds interesting. Have you considered a small (20
gallon) trash can?
Thanks again,
Philip
From: "Bonnie Staffel"
> Dear Philip,
>
> I can only relate that which is my own experience in such non-kiln
> firing processes. I categorize them mainly as Smoke Firing, Sawdust
> Firing, Trash Can Firing and Pit Firing. It sounds like you were
> combining the two middle firings, but not accomplishing either one
> because of some basic errors in planning, IMO. If I am doing a Sawdust
> Firing, I would use some wood as shavings, rather than sawdust, and I
> would also fill the entire slotted container with the shavings
> surrounding the pot, allowing it to fire from the top down, covering it
> after it is smoldering well. That will give you fun markings, mostly
> black, white and gray. I have also used copper in this firing for some
> effects, but not for reds. The heat produced in this firing is not hot
> enough to fume the salt, IMO and would not be a good idea to add to this
> mix. This firing takes all day and maybe into the next, depending upon
> the shavings material.
>
> Next, I will explain Trash Can Firing which I have been using a lot for
> the past several years with some success as I would like the pit fire
> effects without the hole in the ground. Here I would have a trash can
> liberally cut with slashes on the bottom and sides. The work should be
> put on a couple of bricks, then add six or eight inches of Pet Litter,
> sprinkle with copper and salt, place pots on the Pet Litter, add small
> kindling around the pots, gradually filling the can with a little more
> kindling no larger than 1" wide to the top, interspersed with some
> crumpled paper. I squirt some charcoal lighter fluid over the top,
> light it and let it blaze. I let this burn furiously, hopefully with a
> good wind to fan the flames, then cover with the lid partially, only to
> force some heat down. When the fire has gone down to hot coals in the
> bottom then the lid is closed up to about 1" to allow air circulation.
> If the can smokes, then open the lid somewhat until no smoke appears.
> This process takes about 2 hours and you really need a hot fire.
> Different kinds of kindling will produce good or poor effects.
> Hardwoods are the best but Oak in my last firing did not burn furiously
> enough. This will take experimenting with to find the right source of
> wood.
>
> With this last type of firing, you can then hope for copper reds and
> other colors, the salt fuming to give the salmon colors and not creating
> any deterioration to the pot. In comparison, the sawdust firing is not
> hot enough to do much more than to produce carbon in the clay body for
> the blacks. I have also used some clay resist to these pots for
> patterning of my choice. The resist can then be washed off leaving the
> pattern against the gray or black background.
>
> When you mention "lumber" for your wood, it sounds like the pieces are
> too big and thick. Fine kindling is so much better for a furious fire
> and packed tight enough to generate a lot of heat inside the can. I
> might also caution you not to fire this way if you have cold weather.
> That invites cracking and stress to the pot when the bottoms are hot and
> the tops are very cold.
>
> I get very itchy to do one of these firings during the winter, so am
> thinking of placing one of my pots in my electric kiln, put four pieces
> of crumpled paper around it, and light the paper. I am thinking that I
> could have the lid partially propped open so no flames or ash fly out of
> the kiln and also keep the pot from cracking being in the cold garage.
> Is this a nutty idea or does it sound like a workable one? Otherwise,
> could look for a big used metal potato chip can, poke some holes in it
> and fire that outside. It only takes about two or three minutes to burn
> the paper up. But the effects are most times great.
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Bonnie Staffel on mon 9 jan 06
Hey guys and gals,
Tomorrow it is supposed to go up to the 40's here in Charlevoix.
Sunshine and warm rays. I am going to make a small container from my
stash of bricks under the kiln and go for a simple smoke firing. I have
about six pots waiting to be decorated with this process. After the
fire is practically out, I may cover the bricks and pot with a lid just
to keep the heat confined a bit. This should dissipate the winter blahs
for a while. Will let you all know how they came out.
Bonnie Staffel
http://webpages.charter.net/bstaffel/
DVD Throwing with Coils and Slabs
DVD Beginning Processes
Charter Member Potters Council
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