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chronicle of a gas firing, part v

updated sun 14 jul 02

 

Julie Milazzo on fri 12 jul 02


Greeting all! It's five a.m., and some of you may
be up already! Feel free to laugh, as I have just
begun firing down, for the first time. No pyrometer,
little common sense, but I have a brand spankin' new
kiln goddess, named "The Flamecatcher", so things
can't be all bad, right?
I let cone ten drop to nine o'clock on the bottom
(yes, with a Dewalt monster flashlight, I can finally
see the cones...on the bottom...), shut down for half
an hour, then fired it back up to half heat. Cone ten
hasn't dropped any further, so I know it isn't getting
too hot, and there's no way to tell if it's holding
temp, or dropping it, but at least it should drop
slower than if I had just clammed it up. It's a fiber
kiln, and I want more microcrystals.
My favorite recipe is a beautiful rutile wheat
with glossy purples, white, blue, yellow, black, and
many others swirled in. In my kiln, it is a flat,
matte, personality-free peach. Fine for a bathroom
countertop, but yecch on my pots. We'll see.
I have no idea what I'm doing, but at least I
have been learning and logging everything from all
firings. I have a feeling, though, that my kiln is
going to conk out before I ever get it quite right,
but it's the excitement that makes me want a gas kiln,
so what the blank am I complaining about? Anyway, it
should be a good one. Sixteen and a half hours to fire
(I know, I'm working on getting those numbers down a
bit more), then however much more to fire down.
Is it possible for the pressure to drop as the
propane tank empties? It seems that I need higher and
higher PSI to get to temperature, and it's taking
longer. I know it can depend on many things, but just
didn't know if there were any specific rules of thumb
that I might need to know about... Anyway, I'll try to
write Saturday, and give results. Thanks! Jules

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Snail Scott on fri 12 jul 02


At 02:09 AM 7/12/02 -0700, you wrote:
> Is it possible for the pressure to drop as the
>propane tank empties? It seems that I need higher and
>higher PSI to get to temperature...


The pressure inside the tank will drop as it
empties, but you shouldn't have to be resetting
your regulator. That should be constant. Maybe
get your regulator checked?

-Snail

John Baymore on sat 13 jul 02



The pressure inside the tank will drop as it
empties, but you shouldn't have to be resetting
your regulator. That should be constant. Maybe
get your regulator checked?


This is true as long as the internal tank pressure is not dropping BELOW
the regulator input pressure operating range. If it does that, the
regulator loses the ability to "regulate". This is unlikely unless the
kiln is connected to a REALLY small tank for the rate of vaporization
necessary and the manifold pressure for the burners is in the high
range....... 7-20 lbs. sq. in. g. or so.

But I have seen it as people fire portable gas kilns like the small
Olympics and such connected to "trailer" or "barbeque" type culinders.

Best,

..............................john

John Baymore
River Bend Pottery
22 Riverbend Way
Wilton, NH 03086 USA

603-654-2752 (s)
800-900-1110 (s)

JohnBaymore.com

JBaymore@compuserve.com

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