[Clayart] Olympic torchbearer kilns

[James Miner]

Hi Barry. Rob and Hank have some good ideas as to how to fire the Olympic
torchbearer better and more evenly. But if you don't want to completely
rebuild the burner system, there are other ideas. I find the best tips to
be using a top shelf about an inch below the flue, putting the bottom shelf
on 4 inch stilts (both previously suggested), and otherwise firing
according to their firing manual, which used to be on their web site. If
you stall at top temperature, first try turning down the gas or add a
"chimney" of firebrick on top of the lid around the flue.

You can use your stacking method to also help even up the firing...for
example, I normally set my half shelves only about half an inch apart on
the second shelf (not first) in order to keep the heat lower in the kiln.
I find that whether the top or the bottom heats up more depends on whether
you are firing in reduction or oxidation in combination with how you stack.
I don't alternate shelves b/c I often have plates or platters. I don't
block the center burner anymore b/c I had trouble reaching temperature when
I tried to divert it around the kiln. Wastes gas, too. YMMV.

Keep your additional lid for replacements (they tend to crack at lot) or
add to the top (or bottom) for additional insulation. I found that helps
too.

Despite all these "tips" for better firing, I like mine a lot. Great on a
propane bottle for city firing outdoors. No power needed. Might like the
4-burner configuration better, though.

Hey Mel...wanna share that great open clay body recipe? ;)

Cheers
Jim

> I recently purchased an Olympic gas kiln, and have experience with
> updraft difficulties in firing (evenness, reduction vs. temp.
> climb...).
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[Barry Salaberry]

Thanks to all who have responded to my questions about my new (to me) kiln.
I am encouraged and informed from experienced hands.
Best to all,
Barry Salaberry in Penticton, BC

[Lee]

Barry,

I use 3" props for the bottom shelves. When I am close enough
to the exit flue in the stacking, I will put a plate sitter at the hole to
divert the exhaust. With a plate underneath.

Don't know if you saw the link I shared. Here is the text from
it below.

I reiterate, if you want reduction, you cannot
have the primary air on the burners wide open. Close them down to 1/4" or
smaller. Start at 1/4" Easiest way to measure is by using a small piece
of 1/4" plywood to close the gap. And check them before every firing.
They seem to be able to adjust themselves (vibration?)

Also, I put up more shino fired in the TOrchbearer here:

http://shinoglaze.blogspot.com/

Olympic 2831G - Good firing results

I fire to cone 9-10 and (the temperatures) are almost identical top /bottom
with only a few degrees difference through most of the firings. I fire
smaller/larger wheel thrown, slab built rectangle and combo-built ovals up
to about 22" max.

One comment first. You need a dual pyrometer setup. I got a fluke and use
the 12" probes with the ceramic protection sleeves. These fit snug in the
peep holes and keep the probes from sagging. I don't think it's a fire-able
kiln with any success without the dual pyro setup.

I use one probe in top peep and one in bottom. I set a 7,8,9,10 self
supporting cone set on a strip of clay just at the end of the probe inside
about 9-10". At that distance you can see them good later. I use TWO flames
spreaders on two of the four ports. I use a two inch post on each side of
the port with a 5" post laying across them and up against the wall. This
gives a tiny space against wall but directs most flame out. The other two
ports are not tampered with. Bottom shelf is a tad more than 4" above floor
( 1/2" above spreader arrangement 2" post with side-turned post which gives
1 1/2" more height = 3 1/2"). I use two cone six half shelves on floor with
3 1/2" posts supporting the first shelf. Shelves are spaced about 1" apart
and usually staggered 90 degrees, although often I can't get that stagger
or 1" space depending on sizes of pots I'm doing and it never seemed to
make any difference., But, DON'T push them over to touch sides as some
might tell you. Touching together ok, but blocking flames up side not
helpful!
The two biggest keys I found were

1.

Use a baffle shelf at 1 1/2" from inside of top vent. I use an old 1/2
shelf from it that I ruined, or you could use a smaller round/hex shelf if
you desire. My ruined 1/2 shelf works fine, but the 1 1/2" setting I found
was kind of important. It just doesn't work firing without it and if too
close or too far it won't fire even either. I then use a couple small cone
six test kiln shelves for adjusting port air outside on top. They aren't
really even used until late in firing.
2.

The air adjustments on burners are VERRRYYYY important. Once set, never
adjust. Recommendations from the start had me setting them at 1/2" and I
had NO reduction whatever I did, blew it's self out when tried, very noisy.
Michael suggested 1/4" and THAT was the ticket. I couldn't believe the
change. Quiet and reduction achievable. I couldn't believe it.

Now, I fire pretty slow since I have lots of seams in some of my pots and
some good sized. Here's how I fire.

I get up about 6am and start pilot to warm up kiln. Just the pilot and it
warms up a couple hours to about 180-200 degrees before I turn on a low
burner flame. I never go over 250/hr. NEVER. Slow, but I have nothing
ruined. I fire until about 2AMish usually. I'd rather fire longer than
throw out ruined stuff!

I watch pyrometers until about cone 7 then remove them and use peeps to see
cones, in fact, very often I can see top cone pack down through top vent
port if my baffle and cone pack position allow me to do it that firing. My
middle two ports are always plugged (something I didn't do at first).

Now with the air adjustments turned way down on burners I can now adjust
reduction when I want easily with top small shelves across the port and it
doesn't blow its self out like it used to. In fact, next firing I'm going
to tighten the air adjustments even a little more than the 1/4", maybe one
more rotation on threads.

Cones are always easier to see at the top (especially if I can look down
inside) and any temp difference in top to bottom is usually with a hotter
bottom now, but, cones drop almost identical, and a few times when I just
couldn't make out the cones at bottom I used top ones alone and firing was
identical. BTW, I use #5 darkness welding goggles I got at a safety store
for about $8. They work nicer and more comfortable than the old welding
mask I used to use at first. You can also get several kinds of Kevlar
gloves and stainless steel thread gloves at these stores if you need them
for anything, like wood carving.

I'm satisfied with firings now. I should say that ALL I MAKE are bonsai
pots and don't have any fancy glazes that require tricky treatments so I'm
not hampered by that, but now I am getting nicer reduction effects on my
clays that I need to darken up some. I use quite a few different clays,
probably a dozen, and lots of iron, so that in it's self is different than
most people choices of only one or two clays.

To reiterate, the three most important things are, flame spreaders, top
baffle and air plate adjustment.
http://www.bigceramicstore.com/kilns/torch-bearer-firing-tips.html

--
Lee 李 Love in Longfellow,Minneapolis, MN USA

"Ta tIr na n-óg ar chul an tI—tIr dlainn trina chéile"—that is, "The land
of eternal youth is behind the house, a beautiful land fluent within
itself." -- John O'Donohue

[Dale Cochoy]

This is pretty much identical to what I do and it sings! :>)
Lee Love, how long have you had this setup?

Dale Cochoy
Wild Things Bonsai Studio
'Yakimono no Kokoro' Hand-Made Bonsai Pots
Hartville, Ohio
DCo...@neo.rr.com

[Lee]

On Fri, Aug 16, 2013 at 2:19 PM, Dale Cochoy <dco...@neo.rr.com> wrote:

> This is pretty much identical to what I do and it sings! :>)
> Lee Love, how long have you had this setup?
>

Going on two years. I have a 60' run of 1/4" flexible copper. Upgraded
to 2psi Natural Gas (standard residential is .25psi, but high efficiency
furnaces are requiring 2psi, so the upgrade is not unusual) with a step
down regulator at the kiln and to the house. I have plenty of pressure
for the future (considering a natural gas back up generator.)

In the video slideshow below, at 1.18 minutes you can see my setup:

https://www.facebook.com/photo.php?v=10151599532557057

[Dale Cochoy]

I've been running my setup for several years now, about 9 I think?. I had an ex-gas company employee and his son run a flex pipe from my furnace lead out to the garage then solid pipe into the kiln shed behind the garage. It has a shutoff in the house and in the shed. It works great. Setup looks familiar :>)
I used a SELKIRK chimney stack and a friend made the cone attached to it. I wish the shed was a couple feet bigger for some more shelf room but it will last me until I'm done. 7 years ago when I got it down and it started to run great I posted the two emails, with some pictures, that I just reposted the other day. I haven't counted the number of firings but every time I put the cone packs up on the shelf around the inside of my building. When it's full I throw them out and start over. I'm just about to throw them out for the fourth time.

Dale Cochoy
Wild Things Bonsai Studio
'Yakimono no Kokoro' Hand-Made Bonsai Pots
Hartville, Ohio
DCo...@neo.rr.com