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cone 10 electric.

updated sat 9 apr 05


Wes Rolley on fri 8 apr 05

Having just read Jonathan's well reasoned post on electic kilns, I feel
the need to speak up for those of us who have valid reasons, both
practical and aesthetic, to use and electric for firing above cone 6.

I am one of those who do not have to depend on the income from pottery
production in order to live. Our children are both through college. We
are not extravagant and even save money from my megacorp pension.This
gives me considerable freedom to pursue what I want to do. It also puts
some constraints on what I am willing to do that affect my equipment
choices. I am not willing to move.

There is an assumption that most people who fire hotter than cone 6 in
an electric kiln are seeking the "reduction look". I know that is not
my case. I really love the oxidation fired tenmoku look that Mel / Joe
achieved at cone 12, but know that I can not get it. I once achieved
what I would call a "mouth of the dragon coal bed" wood fired look in
the electric (tried to refire a glaze experiment that did not melt well
the first time.) But that is not really what I want to do and it is an
experiment that won't be repeated.

I just want to make the best pots that I can possibly make and to have
fun doing it. Having seen a lot of pots in my life, my standards
started fairly high and I keep raising them all the time. Having fun,
for me, right now, is to thoroughly explore glazes based on using two
components as the basis of the glaze: Redart and unwashed California Oak
(Coast or Canyon live oak) ash. These glazes, mixed in a ration of 2
units of Redart to 1 unit of ash give me a matte or satin matte surface
that I prefer when fired from cone 7 to cone 10. They are quite
sensitive to both temperature and thickness of application in the color
responses (tan, green, brown, red, grey, black, golden) that they give.
I love that variability and am just learning how to control it...get the
color I want in the general area where I want it. The additions of more
iron, small amounts of bone ash and spars have considerable effect.

I am quite happy doing this work with an electric kiln. If I did not use
an electric kiln, I would have to either move, lease a building, or use
a community studio where I would not have control of the firing.
Neither wood nor gas are options for me due to Homeowners Association
rules, worried neighbors, fire code, insurance considerations, etc.

If I had known what I do now when I first purchased my kiln, I would
not have purchased the one I have. It is a popular top loading electric
with minimal insulation (Skutt KM 1027). Right now, it does what I need
it to do, most firings being in the cone 7 / 8 range and only
occasionally needing to go higher. Still, if I were to do it again, I
would definitely purchase an electric with at least 3 in insulation or
3 in plus fiber, either a front loader or at least the 3 in version of
what I have.

For me, the energy cost of firing what I have is not the major concern.
Assume that it would cost $15 US additional to fire this kiln vs. one
with more substantial insulation. The Big Ceramic Store carries the
Skutt KM 1027 for a little under $2000 US. The same source carries the
Paragon Dragon (larger, 4 in insulation) for $3987. The difference in
price would pay for many additional firings, if my estimate of the
energy cost is correct. If my business were manufacturing dinnerware, I
would be very worried about energy cost. It isn't and I am not. The
Skutt KM 1027-3 is less than $100 more expensive than it's
underinsulated cousin and that is well worth the money if firing only
one time a month.

Of more concern to me is the issue of element life. That is a much more
substantial cost to me, money, time and the accumulation of minor damage
to the element grooves. Firing hotter definitely affects element life
in a negative way. Coating elements with ITC products affects element
life in a positive manner, but not enough to equal things out. Beside
the beating that the elements take from firing hot, the use of unwashed
ash adds to the atmospheric attack on the elements. I would love to be
able to order a full set of elements that are factory coated with ITC 213.

"I find I have a great lot to learn =E2=80=93 or unlearn. I seem to know =
far too
much and this knowledge obscures the really significant facts, but I am
getting on." -- Charles Rennie Mackintosh

Wesley C. Rolley
17211 Quail Court
Morgan Hill, CA 95037