mel jacobson on tue 30 may 06
i think in some ways i have been fortunate
in having a small burner on my kiln that
is used to pre/heat before firing.
we use the same system at the farm, only
we have a portable tiny burner with a baso
valve/thermocouple....we use it for over
night firing/heat up. safe. used on several kilns
as it is on a long hose. can reach anyplace
around the firing area. our 3 big kilns are
covered, but dampness in the rural area is
for real.
they are simple to make and easy to use...if
you have the baso valve. that is the only
costly part. most everything needed to make
a burner is at the local hardware store. (see clayart/click below to link.)
page
for a simple plan, and pix of a homemade burner system.) i have
been looking at the baso valves from throw away gas
water heaters...no reason they cannot be made to
work with a tiny burner. (any thoughts on that from
clayarters?)
i added a small burner years ago to my studio
kiln. at the time
i thought i would bisque fire in the gas kiln.
but, i found that the electric kiln was superior
for my purpose. that tiny burner really helps when
firing bisque...slow and easy.
my purpose now in using the tiny burner is to
protect my kiln, shelves and posts. using advancers
most of the time, i find that taking the kiln
to 500F over night dries the pots, kiln and shelves.
i feel confident that firing a kiln with some speed
and not wasting fuel is more than ok. the pots do not
seem to mind. but, it can be hell on a damp kiln
and of course, damp advancers.
we tend to speed up things at the farm after the kiln
has been fired once. most often we unload and load
a warm kiln. close it up and kick butt.
so, i am sure that my pre/heat system has saved me a great
deal of advancer problems.
mel
from: mel/minnetonka.mn.usa
website: http://www.visi.com/~melpots/ (new website)
http://my.pclink.com/~melpots3 old
Clayart page link: http://www.visi.com/~melpots/clayart.html
Wayne Seidl on tue 30 may 06
Well, Mel.
You've opened up another can of worms around here .
Morning sunrise found me outside, in front of the water heater
jotting down column pressures, BTU inputs and other ratings on our
(8 year old, due-to-be-replaced-any-day-now-when-I-have-the-time) 30 =
gallon
propane water heater. Devoted Partner looking at me like I've =
completely
lost my mind as I hop from one bare foot to the other, squashing =
scorpions
and other critters fleeing as I swore loudly, moving things around to =
get to
the heater label. (Here in S. Florida, many houses have water heaters =
and
washer/dryers outside...no danger of freezing.) The critters were not
amused. Here's what I found:
On our water heater, the burner is rated for an input of 35,000 BTU per =
hour
with a WC (water column) pressure of 11, and a manifold pressure of 10. =
The
burner itself is a round plate-style affair, about 8 inches in diameter =
with
holes all around the circumference.
For comparison, I also went to the back yard and looked at our propane =
gas
grill. This is a much simpler affair, with no baso valve or pilot, just =
a
regulator on the small tank, going to two valves with knobs (you adjust)
with two hoses connected to an "H" style burner. It was also rated for
35,000 BTU/hour. No indication of manifold pressures on the unit, or in =
the
literature.
Now, knowing how hot the water heater can get on a regular basis, =
knowing
how hot the grill gets (for us daily, we cook a lot outside) at first
thought I would have to say that it might be a bit overpowered for use =
as a
pre-heat burner on a kiln. However, given the much larger area to be
heated, which is surrounded by (in most cases) IFB or hard brick which =
must
also be heated, and given the thermal load in the firing chamber =
comprised
of shelves, furniture and pots, one should be able to pre-heat the kiln
quite nicely with a burner/baso combination from either a water heater =
OR a
grill. The baso valve of course would lend safety, so I would have to =
opt
for the water heater setup. Considering that I have not had to give =
ours a
second thought for years (except when I had to relight it after various
hurricanes) that combination of baso and burner is pretty much =
trouble-free
and long-lasting.
If you plan to use a burner rescued from a water heater, the trick is =
going
to be to incorporate the burner into the kiln. You are going to have to
find a place in the firing chamber (or the channel leading from the
firebox?) to mount the burner where it won't be affected adversely by =
the
intense heat/ash from the main burners. The water heater burner looked =
to
me to be manufactured from thin sheet steel. Perhaps near the loading =
door
of the kiln, on the floor in a corner. I guess it depends on your
configuration, where your (gas) burners are located, or where your fire
channel enters the kiln chamber.=20
This idea is definitely something to consider. Our water heater costs =
us
about $20/month in propane. That is "always-on" and "on demand". It =
should
cost no more than a buck or two to preheat the kiln using that setup.
I know one water heater that is going to be "missing parts" when it goes =
to
the curb.
Best,
Wayne Seidl
snip
they are simple to make and easy to use...if
you have the baso valve. that is the only
costly part. most everything needed to make
a burner is at the local hardware store. (see clayart/click below to =
link.)
page
for a simple plan, and pix of a homemade burner system.) i have
been looking at the baso valves from throw away gas
water heaters...no reason they cannot be made to
work with a tiny burner. (any thoughts on that from
clayarters?)
snip
mel
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