Tim Lynch on sun 22 jul 01
Hello Everyone: it has been quite a while since I have been on the list.
Life got busy so I signed off for a while. Now, I need help. I have looked
in the archives and all over the web but I need you guys.
I have spent most of this spring and summer building an Olsen Fast-Fire
Wood-Burning kiln out of recycled hard brick. I had to take seven or eight
weeks off as I had carpal tunnel surgery. It kinda slowed me down. I built
it to the specs in Olsen's book. As with anything, sometimes I had to
disregard the book and make do. But I finished it and was convinced it
would hit cone ten the first time I fired it. Whoops. Didn't make it. It
smoked like crazy so I figured it wasn't getting enough air. Before the next
firing I made the outlet from the chamber to the chimney a couple of inches
higher and that seemed to help. It pulled more air this time but after
almost twelve hours I was stuck at about cone 5. I reached cone 06 in about
four hours but it was a struggle after that to keep enough fuel in the
firebox to keep from losing heat. If I stoked too much, it choked and I
lost temp. If I let it burn down, I lost temp.
This model is based on the diagrams and measurements in "The Kiln Book," by
Fred Olsen, Second Edition, pages 128 - 130. I used the photos on pages
131 and 133. It is all hard brick except for the arch which is 2.5 inch #1
insulated arch brick. The fireboxes are about 13" square. The chimney
opening from the chamber to the flue is 9" x 7.5". The chimney itself is
ten feet tall from the chamber. It sits on a foundation of forty hard
brick. I have been using cedar mill ends split into 1" x 1" pieces. I
stoke three to four pieces on one side, wait a few minutes and then stoke
the same in the second firebox. When the coals build up, I rake them and,
once or twice during the firing, pull the grates and shovel the coals into a
washtub. I'm afraid I lose some heat during this process but it appears
that the fire doesn't get enough air if I don't.
My thoughts: I don't think it is pulling enough air. I could make the flue
opening larger by pulling out some brick. I could tear it down (ugh) and
build the fireboxes one layer higher to allow more air. I built the lower
elevation model as our elevation here is about 700 feet above sea level.
Since it is single layered brick, maybe I could use ceramic fiber blanket as
an extra layer to help hold in heat.
I welcome any and all ideas, suggestions, criticism, flaming, whatever.
Tell me I'm an idiot for ever endeavoring to build one of these kilns.
Thanks;
--
Tim Lynch
The Clay Man
1117 Tedford St SE
East Wenatchee, WA 98802
hifired@earthlink.net
Marcia Selsor on mon 23 jul 01
Dear Tim,
What is your altitude. We had the same problem at Banff. It seems the
stack needed to be much higher at 6000 feet.
Marcia in Montana
Tim Lynch wrote:
>
> Hello Everyone: it has been quite a while since I have been on the list.
> Life got busy so I signed off for a while. Now, I need help. I have looked
> in the archives and all over the web but I need you guys.
>
> I have spent most of this spring and summer building an Olsen Fast-Fire
> Wood-Burning kiln out of recycled hard brick. I had to take seven or eight
> weeks off as I had carpal tunnel surgery. It kinda slowed me down. I built
> it to the specs in Olsen's book. As with anything, sometimes I had to
> disregard the book and make do. But I finished it and was convinced it
> would hit cone ten the first time I fired it. Whoops. Didn't make it. It
> smoked like crazy so I figured it wasn't getting enough air. Before the next
> firing I made the outlet from the chamber to the chimney a couple of inches
> higher and that seemed to help. It pulled more air this time but after
> almost twelve hours I was stuck at about cone 5. I reached cone 06 in about
> four hours but it was a struggle after that to keep enough fuel in the
> firebox to keep from losing heat. If I stoked too much, it choked and I
> lost temp. If I let it burn down, I lost temp.
>
> This model is based on the diagrams and measurements in "The Kiln Book," by
> Fred Olsen, Second Edition, pages 128 - 130. I used the photos on pages
> 131 and 133. It is all hard brick except for the arch which is 2.5 inch #1
> insulated arch brick. The fireboxes are about 13" square. The chimney
> opening from the chamber to the flue is 9" x 7.5". The chimney itself is
> ten feet tall from the chamber. It sits on a foundation of forty hard
> brick. I have been using cedar mill ends split into 1" x 1" pieces. I
> stoke three to four pieces on one side, wait a few minutes and then stoke
> the same in the second firebox. When the coals build up, I rake them and,
> once or twice during the firing, pull the grates and shovel the coals into a
> washtub. I'm afraid I lose some heat during this process but it appears
> that the fire doesn't get enough air if I don't.
>
> My thoughts: I don't think it is pulling enough air. I could make the flue
> opening larger by pulling out some brick. I could tear it down (ugh) and
> build the fireboxes one layer higher to allow more air. I built the lower
> elevation model as our elevation here is about 700 feet above sea level.
> Since it is single layered brick, maybe I could use ceramic fiber blanket as
> an extra layer to help hold in heat.
>
> I welcome any and all ideas, suggestions, criticism, flaming, whatever.
> Tell me I'm an idiot for ever endeavoring to build one of these kilns.
>
> Thanks;
> --
> Tim Lynch
> The Clay Man
> 1117 Tedford St SE
> East Wenatchee, WA 98802
> hifired@earthlink.net
>
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--
Marcia Selsor
selsor@imt.net
http://www.imt.net/~mjbmls
http://www.imt.net/~mjbmls/May2001.html
http://www.imt.net/~mjbmls/Tuscany2001.html
http://www.imt.net/~mjbmls/Gallery.html
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