mel jacobson on sat 31 oct 09
des, you hit the nail on the head, but larry has
also found some errors in loading that will give him
1. better firings
2. less cost
by opening the flue area, and letting the kiln work
properly, he saves money, and gets a better firing.
those two things have to go hand in hand.
we sure know that over-packing, crowding the
flue will always result in many failed pots.
poor firing, high rate of failed pots are the
greatest waste of fuel we can find. (then add in over reduction
with dirty, orange flame at the burner you have simple fix at hand.)
fire for 100 percent perfect, with good gas
economy and all win.
i have seen kilns that the potter may just as
well have stuffed kaowool in the flue.
the kiln did not fire worth a damn, but the
same argument comes up, over and over.
`i needed that space to put the last pots in the kiln.`
my take is `well those pots were ruined, so why put them
in there? save them for the next firing.`
but then, some potters have no idea how a kiln works. the
thermo-dynamic part of their learning did not take place.
i sure have found that getting max heat in the kiln
early, get the energy working in the kiln, then turn
things down as the kiln hits about cone1 works great.
nursing the kiln on low hour after hour is just wasted fuel.
(it also destroys the insulation factor of the brick.)
every potter should find that perfect timing for the kiln.
if you need 8 hours, take it. if that is what makes great pots.
so be it. but, if you have a high rate of failure in that 8 hours,
see if you can improve your firing. the biggest problem is
always...WASTE, WITHOUT KNOWING WHY. `my kiln just always
takes 32 hours to fire.` `how big is it?` `22 cubes..why?` `well,
that should fire in 6 hours.` how much gas do you use?`
58 gallons of propane` hmmmmm that would be almost 200 bucks
to fire the kiln...hell, you don't have a hundred dollars worth of pots
in that kiln.`.
(that is a real conversation that i had. i re/built the kiln in a few hours=
.
made a 40 sq inch flue from a 90, put a tight temp metal stack on and
took off the
scrap brick chimney with holes all over. took out a stupid bag wall
that had no purpose, rearranged the shelves.
it fired in about 6 hours, with 15 gallons of propane.)
economy must match the process of firing great pots, that will
demand a good price. that is always the balance. des has it
right on...fire poorly and the price of the pots drops, so what do
you save...NOTHING. in fact, you have just wasted your time, money
and profit.
and, without question, poor firing kilns in public spaces that the
gas bill goes to others, is really awful. and often the people in charge
would kill you for throwing away an aluminum can. they just don't know
what they are wasting. but then...opm....`other people's money..`
who cares? rich people can pay for my ignorance.
mel
from: minnetonka, mn
website: http://www.visi.com/~melpots/
clayart link: http://www.visi.com/~melpots/clayart.html
new book: http://www.21stcenturykilns.com
Lee Love on sat 31 oct 09
One of the reasons I am exploring single fire earthenware is to
produce an "Earth Friendly" line. I buy wind powered electricity and
fire these in electric. Most ecological firing, next to keeping a
woodlot and firing with wood.
--
Lee, a Mashiko potter in Minneapolis
http://mashikopots.blogspot.com/
"Ta tIr na n-=3DF3g ar chul an tI=3D97tIr dlainn trina ch=3DE9ile"=3D97tha=
t is, "T=3D
he
land of eternal youth is behind the house, a beautiful land fluent
within itself." -- John O'Donohue
Des & Jan Howard on sun 1 nov 09
Lee
To me the logical extension of those thoughts would be
to harvest osiers to make baskets, line them with the
unfired clay. Mmm...maybe a range of teacups from birch
bark.
No CO2 up the chimney at your place or the power
station, win/win.
Des
Lee Love wrote:
> One of the reasons I am exploring single fire earthenware is to
> produce an "Earth Friendly" line. I buy wind powered electricity and
> fire these in electric. Most ecological firing, next to keeping a
> woodlot and firing with wood.
Des & Jan Howard
Lue Pottery
Lue NSW
Australia
2850
02 6373 6419
www.luepottery.hwy.com.au
-32.656072 149.840624
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