The Brinks on fri 5 feb 99
I've been reading the posts about this with interest since I live in Lompoc
CA where one of the largest mines of the stuff is just outside of town.
Used to be Johns Manville, now Celite. When you fly over, you can see
whole hills, whole ridges of hills are white- solid diatomaceous earth.
Fossilized diatoms. As has been said, it is a form of silica. Sometimes
wonderful fossils of former sea life of all kinds have been found. There
is a good collection in our local museum.
When my first version of my gas kiln was under construction, I heard of
pink soft brick available free for the hauling ..Johns Manville used to
manufacture brick directly from the d. earth, I think they just compressed
it into brick shapes and fired it. Don't know how hot. Anyway, I was
warned ahead of time that though it was insulating brick, it would
disintegrate after a few firings- get crumbly. As I had a fine frame my
husband had built, and enough hard bricks for the kiln floor, we went
ahead and built up the sides with the bricks, made a roof arrangement of
bricks with rebar going through them , and bricked up the door. So I had
the thrill of the first gas firings. What went first was the roof, it
sagged badly after the first firing. Guess all the bricks shrunk a little
more and we shouldn't have used rebar, should have used other steel rod, I
think. Anyway, we took it all apart and I laid the bricks on a level
place in the back yard. That was about 16 years ago. They have weathered
to a mossy green-pink-brown, and as they are quite absorbent, that is where
I lay out my cloths and pour the clay I have recycled, to dry for a few days.
We remade the kiln---I build a plywood box form, set it on the hard brick
and packed refractory cement around it , in the space between the box and
galvanized sheet metal on the exterior. (Mixed up 14 wheelbarrow loads
myself, while Bill was out of town)-- Used a recipe from an article by
Lowell Baker in Ceramic's Monthly, in fact I talked to him on the phone
about it. After the walls were set we built an arch form and spread about
7-9 " of material on the roof, leaving an opening. This is just an updraft
kiln. I also made large door bricks using a simple form on the driveway.
That all worked heatwise, but the ceiling developed cracks, which I kept
trying to repair. No danger of collapse at all, but it was shedding
crumbs, so that I had to have kiln shelves on top of the top layer of
pots. Then I thought I ought to line the whole thing with refractory
material- and bought a roll of it. I made big ceramic buttons out of
fireclay with holes for the nichrome wire, and we drilled many holes
through the walls and roof of the kiln, and got it all fastened up. Fired
it up, the pots turned out fine, but the ceramic fibre sagged; the wire
didn't hold up. Cone 10, 11 at the top. This was about 4 years ago. I
have a Skutt 1027 which is what I've been using since then, but miss the
reduction firing and am getting ready to make better fiber-holders...sort
of long nail-shaped with an eye at the tip for the wire to go through.
That way the heat won't get to the wire and I hope to have a more or less
trouble free functioning gas kiln again.
I know this got really long...I bet some of you old hands have been shaking
your heads and saying "Too bad she didn't just......." whatever.
Oh, and I just remembered another part to the saga, which I have almost
suceeded in forgetting, my first version of the refractory ceiling ....for
some reason I decided to include chunks of volcanic pumice from the garden
supply store, for lightness. Dumb mistake ...it began melting somewhere
near the end of the firing and when I unloaded the kiln my bowls etc from
the top shelf had what looked like solidified dog food in them. Most of
the ceiling stayed up, but lost a lot of material. It was so awful I
couldn't stop laughing. You can probably tell, I am mostly self-taught,
sometimes properly from people and books, sometimes by big mistakes!
Ann in CA
e-mail billann@impulse.net
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