Brian Murray on sun 25 apr 99
I am posting the following for David Evans, Castle Valley, UT .
David's present access to the net is through me, any guidance on this
subject is greatly appreciated.
I built a Phoenix wood burning kiln as illustrated in Studio Potter,
Volume 7, #2. I have only fired about 6 times and have had some great
results, but I have some questions about the kiln. Does anyone have
experience with this type of kiln?
The firebox builds up so many coals that the air supply becomes
choked. If I rake the coals out it is not only scorching but I lose
temperature. Only the smallest strips of wood seem to make high
temperature possible. I wonder if anyone has any suggestions from their
experiences. Has a Phoenix kiln ever walked, making the lower arch weak?
I am interested in another type of wood burning kiln. Perhaps one
where the coals are contained and with sufficient room to let them lie.
Can one find designs somewhere? Any suggestions?
June Perry on mon 26 apr 99
When I designed my side by side Bourry box wood kiln I built in lots of extra
tertiary holes (2 at the base of each firebox), as well as one in the throat
channel in the main chamber. This allow you to introduce air as well as a
poker to burn down & break up that little mountain of ash. The stirring of
the ash pit also helps put lots of nice ash deposit on the pots. :-)
Hope this helps.
Mark Mondloch on tue 27 apr 99
I built this kiln when that issue of Studio Potter came out and have fired
it successfully about once a month up until last year when I built a gas
kiln. Now I'm still firing it but less often and adding soda. So it's had
I'm sure over 200 firings.
I had some problems with the coal building up at first so the extra layer of
brick in the fire box came out right away. At that time I was also using all
hard wood. Now I switch over to soft- wood (pine slab wood from a log home
builder that they have left from squaring the logs). The soft-wood doesn't
make coals like the hard-wood does, and burns hotter and faster so the ash
pit stays clear. I rake the coals once in a while but never remove any.
When the pit gets cleaned out after a firing, there's only a about a half
of a 5 gallon bucket of ashes to be removed. Make sure the wood is totally
dry too. I try to keep a 2 yr. supply on hand. What do you have in it for
grates? That can be a factor. If they're spaced too wide the coal will fall
through quicker rather then staying on the grates. I also keep a piece of
metal the width of the ash pit and height of the grates propped in front of
the firebox during the firing. This will keep you cooler.
I stick a kerosene torpedo heater in the firebox overnight to warm
everything up before starting to fire in the morning. Then a slow fire with
large reject firewood is started, switching to smaller firewood, and finally
the pine. A typical ^10 firing is 12 hours but could be faster. Don't give
up on your kiln. Once you get the hang of it, it fires easy. I fire it by
myself, get yard work done and play with the dog on firing days.
Brian Murray wrote:
> ----------------------------Original message----------------------------
> I am posting the following for David Evans, Castle Valley, UT .
> David's present access to the net is through me, any guidance on this
> subject is greatly appreciated.
> Brian Murray
> Moab, UT
> I built a Phoenix wood burning kiln as illustrated in Studio Potter,
> Volume 7, #2. I have only fired about 6 times and have had some great
> results, but I have some questions about the kiln. Does anyone have
> experience with this type of kiln?
> The firebox builds up so many coals that the air supply becomes
> choked. If I rake the coals out it is not only scorching but I lose
> temperature. Only the smallest strips of wood seem to make high
> temperature possible. I wonder if anyone has any suggestions from their
> experiences. Has a Phoenix kiln ever walked, making the lower arch weak?
> I am interested in another type of wood burning kiln. Perhaps one
> where the coals are contained and with sufficient room to let them lie.
> Can one find designs somewhere? Any suggestions?
Mark & Sylvia Mondloch
Silver Creek Pottery & Forge
W6725 Hwy 144
Random Lake, WI 53075
R. D. Jones on tue 27 apr 99
Dear Mr. Murray, Mr. Evans,
I have built a Phoenix type (simple cross draft) of wood fired kiln and have
had a number of the problems which you described. My kiln has a fire box
which is lower than the floor of the ware area of the kiln and had a grate
made of 'soap' sized fire bricks spaced approximately four inches apart. We
had a lot of trouble with the ash pit filling with half burned charcoal and
obstructing the air flow. We solved this by placing a grate made of 1/2
inch steel rod spaced 1" apart welded on 3/4" longitudinal rods. We then
painted the grate with the ITC product for steel and have fired it twice
without destroying the grate.
We also had major problems getting the kiln to cone 10 and took these
measures to correct that. #1. I replaced the hard fire brick in the floor
with insulating firebrick so that so much heat isn't lost through the floor.
#2. I reduced the height of the stack to 10' (diameter 10") to reduce the
very vigorous draft which seemed to me to be pulling too many of the BTUs up
the stack. 3. We read the article in the last Ceramics Monthly (April) by
Brian VanNostrand in which he describes arranging the bag wall and kiln
shelves in such a fashion to force the flame into an S curve through the
kiln. We set our kiln up in this fashion and had an unbelievable firing in
which the kiln reached cone 11 in only about 12 hours. We hadn't reached
cone 9 in 18 hours in the previous firing. I'm not sure which of these
things produced the rapid build up of heat, but I believe they all
contributed. It also fired quite evenly.
I am grateful to Mr. Mel Jacobson, and ITC's Mr. Feriz Delkic who graciously
spent a lot of time discussing these problems with me and my potting buddy
Roger Arney at the NCECA meeting in Columbus, Ohio. They warned Roger and I
that this wood kiln would kill us being that we are such old guys playing
this youngs man' sport of wood firing at our ages. So far it hasn't. I
would say this that I believe that if you get up to cone 10 or 11 so rapidly
that to get the desirable flashing that I like, will have to keep a fairly
long soak of 3 to 6 hours at that temperature as I believe Mr. Tony Clinnell
has stated in the past regarding fast firing wood. Anyway this has been our
experience and I hope it will be of some help to you.
PS. Thanks again Mel and Feriz if you happen to see this.
clennell on wed 28 apr 99
I think Sylvia Monlock gave some great advice in firing the Phoenix kiln.
We built two of these kilns both from hard brick and could easily fire them
in 12 -15 hours. I think Sylvias idea about a metal guard to keep you
cooler is a good idea. This is a hard kiln physically to fire. You are
bent over and your face is in the firebox.
Jack Troy gives a chart at the back of his woodfiring book listing woods
that have excellent to poor coaling qualities. If you can pick a wood that
doesn't coal as much.
As for the original list about the woodfirer from Utah. I'd say visit USU
in Logan, Utah and see John Neeley the high priest of wood kilns. John
will have plans as well as about 2 or 3 wood kilns firing the day you get
there. I travelled from north of 49 to Utah to talk with John last year.
Well worth the time and effort. Very knowledgeable, generous and helpful.
Tony and Sheila Clennell
4545 King Street
Beamsville, On. L0R 1B1