Lee on tue 8 apr 08
Paul,
I think without grates and air passing under the burning
wood, you will get very little ash effect. Mostly all you can hope
for is a reduction boost.
Only way you will get ash flying around is if you blew in sawdust.
--
Lee, a Mashiko potter in Minneapolis
http://mashikopots.blogspot.com/
"All that is necessary for evil to succeed is that good men do
nothing." --Edmund Burke
Paul Borian on tue 8 apr 08
my shuttle kiln was originally a gas kiln and the only thing i changed
when i started firing with oil was the burners, so it is still basically a
gas kiln. Right now the burner ports are too small to easily start
incorporating wood and there is no way i could add a firebox to it - but i
could cut an opening right above each burner port and basically make a
second port on each side to throw wood in. But i was wondering how much of
that i could do before i get ash deposit build up all over the shelves and
posts, causing pots to stick to the shelves and that kind of mess. Is that
common to all wood kilns or just the ones that fire for several days at at
time?
the other day i was cleaning up around here and had all kinds of old
pallets laying around so i put them in a pile and burned them all - and
since the kiln was firing as well i could not help but think how stupid it
seemed that i was not doing this inside the kiln. But the ports are too
small to do it easily. At one point i backed the burner out a little and
slid part of a slat from a pallet in there and it seemed to burn well with
no additional smoke (i was thinking it would really smoke up the place
since there was already a fair amount of smoke in there).
There are woods all around my studio with tons of small dead branches
everywhere on the ground - enough to fire a wood kiln for years but i
don't have time to fire completely with wood.
How many people out there are suplementing their gas firings with wood?
any problems?
thanks,
paul
Mark Issenberg on wed 9 apr 08
Funny how that question showed up ,, That's what I was doing yesterday
morning about 9 AM.. I had loaded both Alpines the 24 and the 16 .. In the 16 I
had 6 tall vases things and some slab bowls in the bottom. I had added chunks of
feldspar to 3 of the tall vase things. I pushed the chunks in when they were
soft. I had made the first one at Marco Island at a workshop. I had wanted
to make more but never got around to it. We had been making tiles with the
slab roller and I decided it was time to make the tall vase things.
Any way 3 where glazed with Shark Skin Shino and I decided to burn some wood
in the firing.. I had spit up 2 big chunks of pine and slowly added it to
the burner ports. It wasnt doing much till I turned the air adjusters to no air
then I got smoke and flame.. Way cool. I remember Mel said he had been doing
that for a while.
Well, I wont know if it had any effect till Friday when I open the kiln.
Cant wait..
On another note I also tuned my compost pile yesterday.. Its now about 50
feet long and 6 ft tall. I had rented a dump trailer and hauled 10 loads of
manure up here. I had a great idea on how to use plastic bags that my clay comes
in. I will bag the compost and sell it at the Chattanooga Market on Sundays.
What a great way to use the plastic bags. Once is not enough
Im getting ready to start packing stuff to bring to Appalachian Center for
Craft , Mugs ,Bottles and Bowls. Im hoping to pack and bring and bunch of mugs
to look at .. A good way to see what works and what doesn't ..
Also ,I am turning the computer OFF at night. And I really hate AOL..
Mark
Lookout Mountain
VP PC
PS,, Elvis is going to be Vetted this morning ,,
**************Planning your summer road trip? Check out AOL Travel Guides.
(http://travel.aol.com/travel-guide/united-states?ncid=aoltrv00030000000016)
Paul Haigh on wed 9 apr 08
My wood kiln is a 40 cu ft with a Bourry box. The Bourry box sucks air through the wood pile, so that as ash is created in the burning wood, it is pretty efficiently transported into the ware chamber.
The pots on the bottom, up front in the chamber get nailed. Really blasted. Ash is dripping down the fronts, sticking them to the bricks. I burn a cord and a half of wood (others use less, but I'm going for heavy effects, and use wet wood too)
Here are the caveats- Nowhere else gives me an issue (get some effect all through the kiln), but that is because everything is wadded, including lids. There is NO BAGWALL, or step up from the firebox to the ware chamber, so those front pots act as the bagwall and really take a beating. My buddy Dave loves this- everything needs to be on the front-line for him. Nothing subtle- LOL. We joke that he refires things until they flux through and melt into a puddle.
So- if you wad up the stuff up front that will get it worst, and you're throwing in a face cord in say a 24 cu ft kiln- I wouldn't guess there would be a problem. Just make sure there's enough cross-draft to pull in that ash for some effect. Don't let the ash get to the burners too much, I'd guess. Soak at high temp to melt it up well. If it's a couple pallets, then no biggie. Just remember that those nails will fall somewhere as well (straight down). If they're dirty/sandy- then that goes in and hits pots too.
I think that Mel puts wood in his gas kiln, but not much. He may have something to add here.
Paul Haigh
Londonderry, NH
Bonita Cohn on wed 9 apr 08
Hi Paul. I think you stumbled on a great method.
Sensible and "Green" IMHO (in my opinion).
- A few years ago Otto Heino was present at the
Oakland Museum during the reception for his show. He
is quite friendly and approachable - we had a little
chat: He is famous for a yellow glaze.
He told me how he did it:
He goes to cone 9 with gas and finishes off with wood.
There was a picture of his kiln (that I copied with my
digi-cam)-- I have no idea what kind -- but he was
sitting next to a wheel barrow full of sticks and
stoking alone.
Photo attached.
He fires once a week. Loads Monday...unloads
Thursday...Gets megabucks per week out of that kiln.
The yellow glaze is actually a slip that gets fluxed
by the wood ash that burns fast and relatively
smoke-free.
I wood suggest a port big enough for the wood over the
flame.
Removing the burner like you did might be enough---
Best wishes, Bonita Cohn in San Francisco
-Light the Torch on your kiln!
"At one point i backed the burner out a little
and
slid part of a slat from a pallet in there and it
seemed to burn well
with
no additional smoke (i was thinking it would really
smoke up the place
since there was already a fair amount of smoke in there)."
Bonita Cohn
415.673.0533
http://www.bonitacohn.com
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Steve Mills on wed 9 apr 08
I have a gas Kiln where the burners come up on each side from underneath.
I cut a hole in one side close to the door and made a cover for it, and made a simple long narrow grate to go between the door and the setting. Sometimes when I have a load with a lot of unglazed sufaces, I back of the gas at 1000oC and reduce all the way to the end with wood pushed through the port I made in the side.
Results are variable, but can be really nice. I'm planning to build a small "firebox" in the door with its own (adjustable) air inlet to see if I can develope the idea further.
Steve
Bath
UK
Lee wrote:
Paul,
I think without grates and air passing under the burning
wood, you will get very little ash effect. Mostly all you can hope
for is a reduction boost.
Only way you will get ash flying around is if you blew in sawdust.
--
Lee, a Mashiko potter in Minneapolis
http://mashikopots.blogspot.com/
"All that is necessary for evil to succeed is that good men do
nothing." --Edmund Burke
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