Jonathan Pennington on thu 20 dec 01
* mel jacobson [011220 17:12]:
> hell yes, blow'd that sucker up good.
I've been putting off building my gas kiln for this reason. Before, I
had no experience with an electric kiln, but it's easier to safely
screw up things in an electric kiln (And I have). I have the
electronic kiln sitter, and used that while learning. Gas kilns seem
very different- no automagic timing deal, it's all on you. I'm worried
about things like candling, warming it right, making sure the chimney
is warm, etc. I don't know anything about these things. I'm worried
about building a gas kiln before I have a conceptual framework for
firing it. I'm not grounded yet.
I'm wondering if I can do an internship somewhere and basically be a
kiln slave for a while- hell, I'd take a month or so in the summer and
work all day for room and board alone. It seems like that would be the
way to learn, instead of blowing up my house. I don't think books will
cut it on this one.
-J
--
Jonathan Pennington | jwpennin@bellsouth.net
"There are no pots, there is only clay." -original
"It's hard to take life too seriously
when you realize yours is a joke." -also original
mel jacobson on thu 27 dec 01
hell yes, blow'd that sucker up good.
several safety features with gas kilns that i
sorta insist upon is:
1. use a bernz-o-matic torch/or similar
tool. it has a nice long flame, is hot and can
be used for a number of tasks.
2. light your pilots with your bernz-o-matic.
3. heat your chimney just for a few minutes, make
sure the pre/heated gases are all out, and that the
chimney is pulling up...not down. just stick the
torch on high flame in the slot for your damper.
all those nasties will just start up the stack. (if nothing
else, burn some newspaper in the chimney...even dropping
lit torches of paper down the stack.)
4. if you fire all night with pilots, or on real low,
a great deal of gas can just sit in the back of your
kiln....light the big burners, WHAM, WHOOSH...
and you don't have eye brows any more.
5. and many of us old timers have seen the
`one burner pilot` system come back and bite you.
the odd burner goes out, spewing raw gas into the kiln
and only lights when it crawls over to the other burner.
WHAM, WHOOSH, bricks and eye brows gone.
6. that first hour, that is the critical time.
make sure your kiln is drawing, pulling up the stack
before you turn things on and spew lots of gas in the kiln.
7. hell, you can turn the kiln on and off anytime at
2,000. the new gas just burns. not very much danger
then. now you have to worry about hot stacks and beams.
8. just a few simple safety rules to follow.
9. do it every time. every time. never get sloppy.
10. routine, safety, routine. the key to happy firing.
11. always be a bit frightened...it makes you think.
12. talk to yourself.
yes, talk out loud if need be. `right hand, left hand, saw blade,
icky.` `gas in stack, BOOM.` `go slow, be careful dorko.`
`set the alarm clock`.
the reason i start all kilns at 5 a.m. is that there are no people
or conversation to distract me. i am alone with the kiln for the
first few hours. i don't take a nap/breakfast until the kiln has
it's own energy building. the kiln is nice and pink/red. on it's
own. then i relax.
there is a long, 5 hour or more safety time. it starts at about
1700, or when you start reduction, it lasts until the kiln is at
about 2200F. at this time, the kiln just chugs along, minding
it's own business. at the end, things get damn hot around
the building. the air is full of heat, fumes, crap.
i just dash in, check things, get out. fans on high. sucker fan
on high, air flow on full. check cones...get out.
don't sit there and read a book next to the kiln. stupid.
even out door kilns spew out crap at the end. a wind change
can bring it right down your throat and lungs.
safety. never a joke.
never funny. firing is like going to war. you have to win.
or else.
and, make sure you know what the cones are suppose to look
like before you start the kiln. `today, i am firing so that cone
10's tip just touches the kiln shelf.`. and don't talk yourself
out of that at 3 a.m. when you are exhausted. you just lost
your entire load of pots.
different firings must be fired to slightly different cones. shino
loves hot. rhodes likes cone 10 at 3/o'clock.
the difference between cone 10 and 11 is almost not seen.
often cone 11 goes down at the same time as 10. be aware
of the differences in cone temp. it means a great deal between
5 and 7. be consistent. that is the key to throwing, glazing, firing.
that is what makes crafts people different than artists...consistency.
and, we get to be proud of being consistent.
mel
From:
Minnetonka, Minnesota, U.S.A.
web site: http://www.pclink.com/melpots
Lee Love on thu 27 dec 01
They don't use pilots or other safety equipment on the burners here in
Japan. They do use a little torch that is attached to the fuel line to light
the burners. The commercial gas kilns that almost everybody uses have burners
in the floor, fired propane (butane is available) and natural draft (very
quiet.)
--
Lee Love
Mashiko JAPAN Ikiru@kami.com
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Roger Korn on thu 27 dec 01
mel jacobson wrote:
> ...1. use a bernz-o-matic torch/or similar
> tool. it has a nice long flame, is hot and can
> be used for a number of tasks.
I candle with my bernzomatic, rather than trusting my venturi burners to stay lit
at low pressure.
I can see the burner port that I use for candling from bed - just look once in a
while.
16 cu ft natural gas fiber kiln, but the bernzomatic is hooked up to a propane
tank. I'll usually light the
burners about 3AM and hang out 'til I'm up to 1600 F, just to be sure. No BASO
valves on this kiln, but I
always install them on customer kilns. Just habit - if I'm firing, I'm there 100%
of the time.
Bernzo is also great for coil-and-throw building. I can keep the top at just the
right moisture with hardly
any waiting between adding coils.
I ordered one of those 2-channel thermocouple loggers from Omega so I can record,
download, and plot both thermocouple and oxy-probe millivolts every 30 seconds for
a 20 hour firing. Eventually, I want to try programming both temp and atmosphere by
controlling gas pressure and damper position. For a setup like that, BASOs are a
must - too many ways for something to go wrong and less operator attention required
= more chance for Bad Things to happen.
My little test kiln uses a BASO from a water heater. Thermostat is coated with ITC
213 and shows no degradation after 100s of firings.
>
>
> 2. light your pilots with your bernz-o-matic.
> 3. heat your chimney just for a few minutes, make
> sure the pre/heated gases are all out, and that the
> chimney is pulling up...not down. just stick the
> torch on high flame in the slot for your damper.
> all those nasties will just start up the stack. (if nothing
> else, burn some newspaper in the chimney...even dropping
> lit torches of paper down the stack.)
> 4. if you fire all night with pilots, or on real low,
> a great deal of gas can just sit in the back of your
> kiln....light the big burners, WHAM, WHOOSH...
> and you don't have eye brows any more.
especially true with heavier than air propane. Blew a garage door across the street
that way back in the 60s. My ears are still ringing. Now I trim my eyebrows pulling
raku. Got a cool hat, so I haven't set my hair on fire in over a year.
Thanks for a sensible post, Mel. Keep reminding us to THINK.
--
Roger Korn
McKay Creek Ceramics
In AZ: PO Box 463
4215 Culpepper Ranch Rd
Rimrock, AZ 86335
928-567-5699 <-
In OR: PO Box 436
31330 NW Pacific Ave.
North Plains, OR 97133
503-647-5464
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