mel jacobson on mon 28 jan 08
i think nils lou had the shock of his life
when a kiln that he just turned to high/quick fire...
blew up.
one of the advancer shelves was wet.
blew like a rocket.
he was lucky to survive. his face had been
at the peep about one minute earlier.
i think he has a different view of what
i do now.
warm....the shelves. posts. inside of the kiln.
they never blow when pre/warmed. get rid of the steam overnight.
same thing happened to my friend bob fritz.
two advancers blew his kiln to rubble.
looked like it was hit with a german 88.
mel
like all things with firing, it is about a schedule.
precise schedule.
when you load, when you start, clear time ahead of you.
like flying a plane. care, precise plan.
i do it the same, every time.
like clock work.
from minnetonka:
website http://www.visi.com/~melpots/
clayart site:
http://www.visi.com/~melpots/clayart.html
John Rodgers on tue 29 jan 08
An excellent practice, Mel.
I cannot address exploding shelves, but I can attest to exploding ware -
even ware that has been drying for 8 weeks or longer.
A couple of things - I discovered the hard way that apparently dry
greenware can entrain moisture from the air in sufficient quantities at
certain times, as to cause a steam explosion when fired. I had a
beautiful platter that was bone dry - 8 weeks - and was being readied
for a bisque firing. It rained for two days before the firing took
place. The apparently dry platter was placed in the kiln and fired. It
exploded into a zillion pieces in the kiln. I didn't get the connection
the first time, but when it happened again at another time during wet
weather I took notice. Now I candle my ware before going to temp.
Gas kiln -- my practice was to candle or allow the pilot flame to burn
- all night. the night before and there was sufficient heat to dry
whatever was damp. By the time the shop opened the emp would be around
1250F - just with the pilot flame on. Then the firing would begin.
Electric - I turn the kilns on low, leave the lit cracked open for the
moisture to escape. Same principle. On my paragon computer controlled
kilns when they are set to hold, they will do it automatically and hold
on 204F until the set time runs out and the controller begins to raise
the temperature.
Works well. It's been a long time since I have lost anything due to
steam explosion.
John Rodgers
Chels4ea, AL
mel jacobson wrote:
> i think nils lou had the shock of his life
> when a kiln that he just turned to high/quick fire...
> blew up.
> one of the advancer shelves was wet.
> blew like a rocket.
> he was lucky to survive. his face had been
> at the peep about one minute earlier.
>
> i think he has a different view of what
> i do now.
> warm....the shelves. posts. inside of the kiln.
> they never blow when pre/warmed. get rid of the steam overnight.
>
> same thing happened to my friend bob fritz.
> two advancers blew his kiln to rubble.
> looked like it was hit with a german 88.
> mel
>
> like all things with firing, it is about a schedule.
> precise schedule.
> when you load, when you start, clear time ahead of you.
> like flying a plane. care, precise plan.
> i do it the same, every time.
> like clock work.
> from minnetonka:
> website http://www.visi.com/~melpots/
> clayart site:
> http://www.visi.com/~melpots/clayart.html
>
> ______________________________________________________________________________
> Clayart members may send postings to: clayart@lsv.ceramics.org
>
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>
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>
>
>
Lee on tue 29 jan 08
On Jan 29, 2008 8:57 PM, John Rodgers wrote:
> An excellent practice, Mel.
>
> I cannot address exploding shelves, but I can attest to exploding ware -
> even ware that has been drying for 8 weeks or longer.
Hi John,
We were talking about glaze firing. But Japan is "The Land
'O Wet" except in winter. Potters here make optimal use of wind and
sun, when they have it. As an apprentice, one of my jobs was to turn
work left out in the drive and then chase the sun with the ware
boards, moving them as the shadows moved. Ah, fond memories!
--
Lee in Mashiko, Tochigi Japan
http://mashikopots.blogspot.com/
"Tea is nought but this: first you heat the water, then you make the
tea. Then you drink it properly. That is all you need to know."
--Sen No Rikyu
"Let the beauty we love be what we do." - Rumi
Lee on tue 29 jan 08
On Jan 29, 2008 12:09 PM, mel jacobson wrote:
> one of the advancer shelves was wet.
> blew like a rocket.
Humm. Captives to our toys? You reinforce my desire to stay away
from Advancers.
--
Lee in Mashiko, Tochigi Japan
http://mashikopots.blogspot.com/
"Tea is nought but this: first you heat the water, then you make the
tea. Then you drink it properly. That is all you need to know."
--Sen No Rikyu
"Let the beauty we love be what we do." - Rumi
Taylor Hendrix on tue 29 jan 08
John,
Ditto says the newbie electric firer. I have had some large 12" bowls
drying for several weeks then we had 10 straight days of rainy, cold
weather. I fired off a soft (08) bisque and the bottom bowl in a two
bowl bung (If a wood chuck could chuck wood...) blew its foot off. No
real shrapnel but still hate to see it go like that. When Lezlie comes
over today we'll hammer it and see if my trimming could have been a
bit timid as well.
Taylor, in Rockport TX
On Jan 29, 2008 5:57 AM, John Rodgers wrote:
> An excellent practice, Mel.
>
> I cannot address exploding shelves, but I can attest to exploding ware -
> even ware that has been drying for 8 weeks or longer.
>
> A couple of things - I discovered the hard way that apparently dry
> greenware can entrain moisture from the air in sufficient quantities at
> certain times, as to cause a steam explosion when fired. ...
KATHI LESUEUR on tue 29 jan 08
Just to clarify. The firing schedule I mentioned was for a glaze
firing. I never bisque in my gas kiln. Always in the electric where
I, also, go very slowly.
Kathi
Hank Murrow on wed 30 jan 08
On Jan 29, 2008, at 5:48 AM, Lee wrote:
>
> Humm. Captives to our toys? You reinforce my desire to stay away
> from Advancers.
Dear Lee;
Not that much captivity, actually. I keep my Advancers in a sort of
closet that has a small lightbulb underneath which provides enough
heat to keep them dry and ready for a firing. Only needed part of the
year.
Cheers, Hank
Lee on thu 31 jan 08
On Jan 31, 2008 4:11 AM, Hank Murrow wrote:
> Not that much captivity, actually. I keep my Advancers in a sort of
> closet that has a small lightbulb underneath which provides enough
> heat to keep them dry and ready for a firing. Only needed part of the
> year.
Enough captivity. ;^) But then, I see the Mac as being captivity too! Haha!
My light carbide shelves were once used in Seto in commercial
porcelain kilns. When they were retired from there (they retire them
on schedule), my brick guy bought them, sorted out the best and sold
me them for 1000 yen (under $9.00 each at the time.) They sit
outside under the eaves when they aren't in the kiln. Am thinking of
sea freighting them to Minneapolis.
These Japanese carbide shelves are what the cheap Chinese
ones copy, but without the same quality control.
--
Lee in Mashiko, Tochigi Japan
http://mashikopots.blogspot.com/
"Tea is nought but this: first you heat the water, then you make the
tea. Then you drink it properly. That is all you need to know."
--Sen No Rikyu
"Let the beauty we love be what we do." - Rumi
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