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mandatory musing on an old kiln : olbie seeks advice!

updated mon 3 nov 03


Stephani Stephenson on sun 2 nov 03

it finally happened
23 years, first time I over-fired a kiln due to the Dawson

The kilnsitter released with it's comforting
which I can hear no matter where I am
but something had gone wrong, the button did not release.
I was there , even cracked the lid 3 hours later (i do this
because my Cress CH8 is so insulated that if lid is not
cracked a bit the kiln takes a week to cool down)
I thought it was a bit orange, but then as I say...this
thing doesn't lose heat.
Funny how I marched right by a red flag. Also I ALWAYS turn
the switches OFF when I double check to see that the kiln is
finished. This time a customer stopped by and i didn't,
And I guess because the thing has worked so well , so long,
I got lazy....
The end of the pyrometer had broken in a firing a few weeks
ago .
Had been using a replacement, but it was hooked up to the
gas kiln that day.
The kiln fired 6 more hours before the timer turned it off.
so take from me..... don't get lazy ,folks!!!!!

Anyway I lost the load but the kiln is basically OK,...I had
low fire refractory, lowfire kiln wash, and lowfire
the refractory failed, including some pin setters and I had
one ugly collapsed sculpture in the center .
don't know how hot it actually got... I hear that lowfire
refractory gets gray at cone 3...nothing was a puddle but
the terra cotta looked like a batch of brownies.
wiring OK but the collapse broke 2 or 3 of the 5 elements.
the tube assembly on the kiln setter was also damaged.

I felt so bad about hurting this wonderful kiln. Les
Hayworth at Laguna was very prompt and helpful the next day
giving me some advice and pointing me to replacement parts..
At one point I thought OH HECK! I'll just buy a new kiln so
I started looking around at what was out there.

The first thing that surprised me was how expensive these
particular models are to replace. I looked at this kiln,
which was new in 1972, with a new appreciation. This big
square welded frame faded rose which I bought for $100 is a
$6000 kiln. Then I looked at what I could buy for $1000 to
$1500....mine is 8 cubic ft.... I liked the idea of getting
a similar size one with a computer controller, but I also
like the 6" of insulation mine has on all sides.....
I didn't find much that could compare for the $ I had to
spend so I decided, and Les concurred, to save the old kiln
and give it a facelift , some TLC and a some long overdue

one thing which really intrigued me as I was checking out
new kilns was that , in general the larger 'studio' model
electric kilns we are all use to , the octagons, etc. really
draw a lot more Amps.... some of them require 70, 80,90 amp
breakers....This big old behemoth kiln of mine draws much
less...38 amps, (I have a 50 amp breaker.).. so I wonder why
this is? Right now I am not remembering very much of my
electricity 101 so can someone tell me does this translate
into higher power usage per unit of time when the kiln is
on full power for example?
when one compares a kiln drawing 80 amps v. one drawing 50 ,
for example????
So what in the kiln or element design calls for the
increased AMPs needed on these newer models? old Skutt
1027 needed a 60 amp.... but I don't recall seeing 70,80,90
Is it just that the super insulation allows the kiln to fire
less (by switching on and off during heat rise) and thus
draw less?

So, this is what really made up my mind ,along with the
sheer durability of my old kiln. To me , it is kind of like
a 52 Chevy, 6 cylinder Pickup....Durable as hell, smooth
running, easy on the gas consumption, made of good steel.
I liked that this Cress drew a smaller amount, simply
because it is easier to 'fit' into a breaker box, not
physically, but when rationing out the power to the various
breakers... I don't think the studio breaker would have
accommodated 90 for this particular kiln outlet in concert
with other studio electrical needs.. Anyway, something to
keep in mind when shopping for a kiln.

So I am rebuilding the kiln. Replacing all of the elements,
hoping they arrive tomorrow. Patching some of the age lines
in the brickwork, and some of the gouges. The bottom of the
kiln is OK, I always have some shelves on the bottom to
protect the floor itself and some hi temp kiln wash. getting
a new tube assembly for the kilnsitter and a new pyrometer.

I am going to put the 2 different ITCs on the interior and
on the elements and I am really tickled about finally being
able to do this..

One question I do have .. these elements have small
diameter, long refractory clay cylinders .These are
inserted into the element coils. I am hoping to replace
them, and wonder if I should coat them with the same ITC
which goes on the brickwork? Has anyone done this? any tips?

Also , this kiln is sometimes exposed to damp air ...we are
not too far off the ocean, and am starting to see some rust
on the jacket . Can anyone recommend a product to protect
against the rust which will withstand heat? also
with regard to element terminals...Even inside the box the 2
upper ones were starting to corrode from rust...anything one
can put on them to protect against rust but still safe with
regards to electrical connection?

SO I have had some time to muse about kilns the last couple
of days while getting this one ready for it's overhaul.
I don't think you really know the kiln till you get inside
it and so I just hope I can get it back to ship I
my mea culpa's!!!!! If kiln petting helps I will do it!!!!

P>S I do have access to a gas kiln to use as a back up...
but I actually prefer the electric for some of my glazes.
Stephani Stephenson