Hendrix, Taylor J. on sun 16 feb 03
Hello all:
Took a trip this weekend down to Salado, TX, a nice arts/antiques town
about 60 minutes south of Waco. It's home to two potters that I know
of, one of whom is Jim Dale. Very nice man. Bought a mug from him
(Don't worry David. You're still my first). He's such a nice fella
that when I went back to his store to ask him about my raku conversion,
he left his shop and took me around the corner to his studio to take a
look at his set up. Cool! Of course I acted like it was no big deal,
BUT I was actually chanting in my head, "I'm in Jim Dale's studio, nah
nah nah nah nah." Anyway, he gave me some very good advice about the
conversion, so I did some running around on Sat. pricing materials and
need some more expert advice.
My teacher and I are going to convert an old 3.2 cu. ft. Paragon
Highfire to raku. I was contemplating cutting a burner port in the side
and flue in the lid, but that would reduce the firing chamber size. Jim
suggested removing the lid, using it as the floor of the firing chamber,
cutting out the bottom, stacking two courses of soft brick with the
burner port being a half brick. The lid could be made out of hardware
cloth and some fiber blanket. Easier to manipulate than the existing
lid. I very much like this suggestion.
Now the burner. Here is where we need some advice. The Branfman _Raku_
book has some rules of thumb for b.t.u. requirements. 4.5" G-20 A.P.
ifb: 18,000 per cuft. 2.5" G-20 A.P. ifb: 32,000 per. I have priced a
burner at Home Depot (tar burner, weed burner, etc) with 10' hose and
what looks like a needle valve at $50 US. I thought its stated rating
was 500,000 btu, but that sounds like an awful lot. Perhaps I wrote it
down wrong. I thought Jim Dale suggested at least 75,000 btu and a high
pressure regulator for propane, but maybe I'm just a sieve brain (36
mesh) and can't remember numbers to save my live. Hep me!
Branfman's Btu/hr/cu. ft calculation would give us 150,400 for our
conversion (adding the two courses of brick adds 9" to height, thus 4.7
cu. ft. interior). Wow, the poor man's home depot weed burner appears
to be much more than needed. This just can't be right. What am I
missing? And, can I assume that this weed burner which does not come
with a regulator will work fine at propane tank pressure and thus a high
pressure regulator won't OVER power it?
Thanks for all the help, and all you Texans out there, go to Salado and
buy a Jim Dale pot. He had just finished firing his car kiln, but it
was still too hot to open. ARGH for me, but YEAH for you.
Taylor, in Waco where it's snowing?
p.s. While we were looking through some antique store, I found myself
hunting for things I could make into clay tools. It struck me when I
was eyeing a box full of old, EXPENSIVE button hooks that I have really
gone off the deep end. Well, thanks to clayart, the water's warm.
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