Mark & Linda on fri 26 dec 03
Donald. THe next jump up is dry pressed high alumina shelves from
england such as acme marls. I used 40 of them for many years .But a
much better investment are the advancer shelves from smith-sharp. I
have 45 of them now and they stay flat at cone 11> yes stay flat at
cone 11 with over 100 glaze fires on them. They weigh 9# for a
12X24. The only drawbacks are that they are very subject to thermo
shock and they cost 135$ apiece. I love them, Did I say that they
stay FLAT at cone 11. Mark Cortright
Donald G. Goldsobel on fri 26 dec 03
After many years, I need to get some more 12 x 24 high fire shelves for el
horno- the faithful firebox.I have Thorleys now, but they are old and real
heavy- like me.
Any advice from those of you who have used different types of shelves in the
past?
Thank you all and a Happy New Year
Donald
Vince Pitelka on sat 27 dec 03
> If you can afford them, silicon carbide is far superior. One of their
> best qualities is that glaze doesn't eat into the surface like it does
> on high alumina shelves. With SiC it pops off easily with a chisel.
Paul -
I cannot remember whether the original post specifically referred to a wood
kiln. If so, then I would agree that silicon carbide shelves are better.
And for salt and soda they are the only reasonable choice.
For standard reduction or oxidation kilns many people still feel that
silicon carbide shelves are the best choice, but with the quality and price
of high-alumina shelves available today, I do not recommend using silicon
carbide, unless one has the money to spend on the thin, ultra-light Crystars
or Advancers. High-alumina shelves are far less expensive than silicon
carbide, they weigh less, and they hold up very well. If you get good
quality ones, there are no problems with warpage. If you use a good shelf
wash, there are few problems with glaze runs burning into the shelves. That
does happen occasionally if you experience serious glaze runs. When that
happens we just grind it out and fill it with greenpatch. Also, high
alumina shelves are far less prone to cracking from uneven heating or
cooling. That can be a serious problem with silicon carbide shelves.
We use our downdraft reduction kiln very heavily. About five years ago we
purchased 50 shelves on bid from Axner - 13x26x1" high alumina. We stashed
most of them in strorage on a high shelf in the raw materials cage, and put
a dozen into service. Of that original dozen, we have replaced several that
got broken through carelessness, but the others are still in excellent
shape. That supply of shelves is going to last us for decades.
Best wishes -
- Vince
Vince Pitelka
Appalachian Center for Craft
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
Home - vpitelka@dtccom.net
615/597-5376
Office - wpitelka@tntech.edu
615/597-6801 x111, FAX 615/597-6803
http://iweb.tntech.edu/wpitelka/
http://www.tntech.edu/craftcenter/
Paul Herman on sat 27 dec 03
Hello Mark,
Aren't those thin Advancer shelves a high quality Silicon Carbide? I
haven't tried them yet, but the thought of packing a few more pots in
each firing is appealing. Probably, it would be good to call Lois at
Smith-Sharpe and get a last minute deduction. Maybe you can talk me into
it.
You remarked:
Would you explain that remark a bit more? Have you had some fail from
thermal shock, and if so, how did they do so?
I recall reading a "warning" about them, that if dampened, they need to
be dried "VERY" long and carefully, or they might BLOW UP with all your
nice pots on them. Have you ever had one blow up? Does anyone out there
in the Most Esteemed Clayartland know anything about this disturbing
possibility?
And BTW, did you tell us if they would stay flat at ^11 ???
Stay Flat,
Paul Herman
Great Basin Pottery
423-725 Scott Road
Doyle, California 96109 US
potter@psln.com
----------
>From: Mark
> One other thinh about those advancer sheleves. Nothing sticks to them
> ever nor can you grind inti them the glazes does not penatrate the
> surface ever. Did I say they stay flat at cone 11.Mark
> www.liscomhillpottery.com
Paul Herman on sat 27 dec 03
Hi Donald,
If you can afford them, silicon carbide is far superior. One of their
best qualities is that glaze doesn't eat into the surface like it does
on high alumina shelves. With SiC it pops off easily with a chisel.
Best wishes,
Paul Herman
Great Basin Pottery
423-725 Scott Road
Doyle, California 96109 US
potter@psln.com
----------
>From: "Donald G. Goldsobel"
>To: CLAYART@LSV.CERAMICS.ORG
>Subject: Time to get more kiln shelves- polling the troops
>Date: Fri, Dec 26, 2003, 1:53 PM
>
> After many years, I need to get some more 12 x 24 high fire shelves for el
> horno- the faithful firebox.I have Thorleys now, but they are old and real
> heavy- like me.
>
> Any advice from those of you who have used different types of shelves in the
> past?
>
> Thank you all and a Happy New Year
>
> Donald
Mark & Linda on sat 27 dec 03
One other thinh about those advancer sheleves. Nothing sticks to them
ever nor can you grind inti them the glazes does not penatrate the
surface ever. Did I say they stay flat at cone 11.Mark
www.liscomhillpottery.com
>Hi Donald,
>
>If you can afford them, silicon carbide is far superior. One of their
>best qualities is that glaze doesn't eat into the surface like it does
>on high alumina shelves. With SiC it pops off easily with a chisel.
>
>Best wishes,
>
>Paul Herman
>Great Basin Pottery
>423-725 Scott Road
>Doyle, California 96109 US
>potter@psln.com
>
>----------
>>From: "Donald G. Goldsobel"
>>To: CLAYART@LSV.CERAMICS.ORG
>>Subject: Time to get more kiln shelves- polling the troops
>>Date: Fri, Dec 26, 2003, 1:53 PM
>>
>
>> After many years, I need to get some more 12 x 24 high fire shelves for el
>> horno- the faithful firebox.I have Thorleys now, but they are old and real
>> heavy- like me.
>>
>> Any advice from those of you who have used different types of shelves in the
>> past?
>>
>> Thank you all and a Happy New Year
>>
>> Donald
>
>______________________________________________________________________________
>Send postings to clayart@lsv.ceramics.org
>
>You may look at the archives for the list or change your subscription
>settings from http://www.ceramics.org/clayart/
>
>Moderator of the list is Mel Jacobson who may be reached at
>melpots@pclink.com.
Earl Krueger on sun 28 dec 03
On Saturday, Dec 27, 2003, at 18:16 US/Pacific, Mark & Linda wrote:
> One other thinh about those advancer sheleves. Nothing sticks to them
> ever nor can you grind inti them the glazes does not penatrate the
> surface ever. Did I say they stay flat at cone 11.Mark
> www.liscomhillpottery.com
>
Well, Mark. I think you've almost got me convinced.
But there's still one question I need answered.
Do these shelves stay flat at cone 11?
Earl (a little slow sometimes) Krueger
Bothell, WA, USA
Hollis Engley on sun 28 dec 03
----- Original Message -----
From: Paul Herman
Subject: Re: Time to get more kiln shelves- polling the troops
> Hello Mark,
>
> Aren't those thin Advancer shelves a high quality Silicon Carbide? I
> haven't tried them yet, but the thought of packing a few more pots in
> each firing is appealing. >
> I recall reading a "warning" about them, that if dampened, they need to
> be dried "VERY" long and carefully, or they might BLOW UP with all your
> nice pots on them. Have you ever had one blow up? Does anyone out there
> in the Most Esteemed Clayartland know anything about this disturbing
> possibility?
>
Paul: Yes, I have seen a warning about the Advancer shelves being liable to
explosion if they're allowed to retain moisture. It almost seems to me that
I saw the warning in an ad in CM ... Worse, though, I have a friend here on
Cape Cod who bought a number of Advancer shelves from another potter, stored
them for a while in what she thought was a dry shed, then used one in a
firing to try it out. She brought the kiln up to temperature slowly, being
cautious because of the new shelf. Not cautious enough, apparently, because
the shelf exploded with bang and took many of the other shelves and most of
the pots with it. It even blew a shard out one of the spy holes, which would
not have been a happy occurrence if the potter had been checking the
interior at the time. Soooo ... you apparently do have to be careful with
those things.
Hollis Engley
Hatchville Pottery
Falmouth, Mass.
hengley@cape.com
Rikki Gill on sun 28 dec 03
Hi Hollis ,
I have been using my advancers for years. Fear of them being knocked over
and broken led me to always store them indoors. If you do that, there is
no problem. I fire to cone 11, they are all flat, they clean easily, they
are just wonderful. The only problem is that kiln posts tend to stick to
the corners. They can leave a small lump of whatever they are made of, that
is hard to remove. I fixed that by putting alumina hydrate in wax resist
and painting both ends of the posts with it. That way you have control over
where the alumina goes.
Hope this helps. From Rikki in freezing Berkeley
rikigil@cwnet.com
www.rikkigillceramics.com
----- Original Message -----
From: "Hollis Engley"
To:
Sent: Sunday, December 28, 2003 7:22 AM
Subject: Re: Time to get more kiln shelves- polling the troops
> ----- Original Message -----
> From: Paul Herman
> Subject: Re: Time to get more kiln shelves- polling the troops
>
>
> > Hello Mark,
> >
> > Aren't those thin Advancer shelves a high quality Silicon Carbide? I
> > haven't tried them yet, but the thought of packing a few more pots in
> > each firing is appealing. >
> > I recall reading a "warning" about them, that if dampened, they need to
> > be dried "VERY" long and carefully, or they might BLOW UP with all your
> > nice pots on them. Have you ever had one blow up? Does anyone out there
> > in the Most Esteemed Clayartland know anything about this disturbing
> > possibility?
> >
> Paul: Yes, I have seen a warning about the Advancer shelves being liable
to
> explosion if they're allowed to retain moisture. It almost seems to me
that
> I saw the warning in an ad in CM ... Worse, though, I have a friend here
on
> Cape Cod who bought a number of Advancer shelves from another potter,
stored
> them for a while in what she thought was a dry shed, then used one in a
> firing to try it out. She brought the kiln up to temperature slowly, being
> cautious because of the new shelf. Not cautious enough, apparently,
because
> the shelf exploded with bang and took many of the other shelves and most
of
> the pots with it. It even blew a shard out one of the spy holes, which
would
> not have been a happy occurrence if the potter had been checking the
> interior at the time. Soooo ... you apparently do have to be careful with
> those things.
> Hollis Engley
> Hatchville Pottery
> Falmouth, Mass.
> hengley@cape.com
>
>
____________________________________________________________________________
__
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
melpots@pclink.com.
>
>
Earl Brunner on sun 28 dec 03
I wasn't there when it happened but I've seen the fragments from one
that blew up in Tom Coleman's kiln a few years ago. So it can happen.
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of Paul Herman
Sent: Saturday, December 27, 2003 11:11 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: Time to get more kiln shelves- polling the troops
I recall reading a "warning" about them, that if dampened, they need to
be dried "VERY" long and carefully, or they might BLOW UP with all your
nice pots on them. Have you ever had one blow up? Does anyone out there
in the Most Esteemed Clayartland know anything about this disturbing
possibility?
Mark & Linda on sun 28 dec 03
Earl check out my post to Paul Herman on these shelves. Did I say they stay
Flat at cone 11. Only the first 1000 glaze fires, then you die. Mark
>On Saturday, Dec 27, 2003, at 18:16 US/Pacific, Mark & Linda wrote:
>
>>One other thinh about those advancer sheleves. Nothing sticks to them
>>ever nor can you grind inti them the glazes does not penatrate the
>>surface ever. Did I say they stay flat at cone 11.Mark
>>www.liscomhillpottery.com
>>
>
>Well, Mark. I think you've almost got me convinced.
>But there's still one question I need answered.
>
>Do these shelves stay flat at cone 11?
>
>Earl (a little slow sometimes) Krueger
>Bothell, WA, USA
>
>______________________________________________________________________________
>Send postings to clayart@lsv.ceramics.org
>
>You may look at the archives for the list or change your subscription
>settings from http://www.ceramics.org/clayart/
>
>Moderator of the list is Mel Jacobson who may be reached at
>melpots@pclink.com.
Mark & Linda on sun 28 dec 03
Hello Paul. It is a small world indeed. I am the potter who stopped
by your place last September on the return trip from an art show in
Denver, I left $ behind and took one of your small covered jars. It
sits in the kitchen today. It is also good to know that there are
REAL working potters out there on this forum.
Those advancer shelves I think are recrystalized silicon carbide.
They are nothing like our usual silicon carbide shelves, which I gave
up using many years ago for dry pressed high alumina English shelves.
My 1 inch x12 x24 high alumina shelves are 33#s apiece. The same
advancer is less than 3/8" thick and wieghs 9#s. For my car kiln
that's 600# less shelves I'm moving per load and two more feet of
stacking space. Depending on how many firings per year you do they
will pay for themselves fairly soon. I have had 4 crack over the past
3 years. Most were from uneven stacking pressure. Like a high spot on
a stilt with the next above stilt slightly offset. My fellow potters
used to pull their damper during cooling which cost them a few
shelves. NO quick cooling with these shelves.If your chimminy leaks
air keep them away from the flue. I also have heard about one
exploding due to moisture. They can blow up whem wet but so can pots,
just keep them dry and you will have no problems. I just ordered 10
more. I have over 40 of them already. The price break is 10 and they
are going up next year in price. They have to order them which takes
some time. These shelves do not absorb glaze at all and seem to be
impossible to grind into which makes for great clean-up after any
runs. They are much denser than silicon carbide grinding wheels.
Porcelain feet tend to stick but a very thin wash works well. I deal
with Donna at smith-sharpe supply - 866-5456743. These rate right up
with the POWER wheel, Giffen grip, Talisman sieve, and 1-ton van, as
far as inventions for us potters. My only regret is I did not get
them sooner in my career - my back would be much better if I had.
How often do you fire your wood kiln? Good luck, Paul.
Mark Cortright wwwliscomhillpottery.com
>Hello Mark,
>
>Aren't those thin Advancer shelves a high quality Silicon Carbide? I
>haven't tried them yet, but the thought of packing a few more pots in
>each firing is appealing. Probably, it would be good to call Lois at
>Smith-Sharpe and get a last minute deduction. Maybe you can talk me into
>it.
>
>You remarked:
>
>>>
>Would you explain that remark a bit more? Have you had some fail from
>thermal shock, and if so, how did they do so?
>
>I recall reading a "warning" about them, that if dampened, they need to
>be dried "VERY" long and carefully, or they might BLOW UP with all your
>nice pots on them. Have you ever had one blow up? Does anyone out there
>in the Most Esteemed Clayartland know anything about this disturbing
>possibility?
>
>And BTW, did you tell us if they would stay flat at ^11 ???
>
>Stay Flat,
>
>Paul Herman
>Great Basin Pottery
>423-725 Scott Road
>Doyle, California 96109 US
>potter@psln.com
>
>----------
>>From: Mark
>
>> One other thinh about those advancer sheleves. Nothing sticks to them
>> ever nor can you grind inti them the glazes does not penatrate the
>> surface ever. Did I say they stay flat at cone 11.Mark
>> www.liscomhillpottery.com
>
>______________________________________________________________________________
>Send postings to clayart@lsv.ceramics.org
>
>You may look at the archives for the list or change your subscription
>settings from http://www.ceramics.org/clayart/
>
>Moderator of the list is Mel Jacobson who may be reached at
>melpots@pclink.com.
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