David Jenkins on thu 15 feb 01
Last month there was a thread about making pots which you liked to use yourself. At least one person mentioned that he no longer made casseroles since he no longer used them himself. I felt the same way about casseroles until December when I mixed 150 lbs. of flameware clay and made a dozen casseroles, tureens, cooking pots to give to family/friends for Christmas.
I kept two for myself and I have been having a great time using them. Just put it on the stove, turn the flame to high, and you are cooking! I have been making chicken stew, spagetti sauce, beans and rice, fish chowder, soups, etc. It is so cool to be able to cook right on top of the stove and then put the pot on the table to serve. I also made a few smaller sauce size pots which are great for heating and serving sauces in or hard boiling eggs. I am now working on a few tea kettles for boing water in.
I am wondering why more potters don't use flameware clay, at least for their own personal use. I don't think I would make flameware pots and sell them as flameproof because of liability questions, but it is a great clay to use for cooking pots. I am considering using this clay for all my casseroles and baking dishes since it is so durable. The only problem I had with this body was that lids are very difficult to remove. I tried to use aluminum hydrate mixed with my wax for waxing the rims but this did not help. I lowered the firing temperature to cone 9 but this did not seem to help either. Luckily the larger pots that I did had a ladle slot that I was able to stick a dowel through and pry the lids off. The smaller beanpot size pots I did with flat lids which I fired seperately.
The formula I used was from an article by Ron Propst in the Studio Potter Book published in 1978 by Studio Potter magazine. There is also a section on flameware in The Craft and Art of Clay by Peterson. Both of these sources mention glazes that fit well on flameware. I just used a spodumene glaze on mine since there is a high percent of spod in the clay body it should fit well.
from David Jenkins on the coast of Maine where I have spent the last two days up on the roof with a shovel and ax removing snow and ice dams. Hope it is warm in Charlotte.
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freeflt on thu 15 feb 01
I'm curious, what cone to you fire your flameware to? I tried some, =
fired it to cone 10 and the body bloated horribly. Read an article =
written by Propst that said it was a cone 8 body, I figured the bloating =
was due to firing too high for the body. Was I wrong about this?
~sherry wells
free flight pottery
nw montana, where today all the schools are closed due to about 6 inches =
of snow last night, everything is covered in white and it's beautiful!
Craig Martell on thu 15 feb 01
At 06:15 PM 2/16/01 +1300, you wrote:
>Craig,
>I'm intrigued by this idea that spodumene is not a mineral... Four of my
>mineralogy texts I regularly use are under the impression that it is a
>mineral, and a well defined one at that.
Hi Michael:
I would be intrigued too owing to the fact that my statement was total
BS. What I posted to Clayart was totally wrong and should classify as
complete nonsense. What I meant to say was that spodumene is not classed
as a feldspar but a lithium feldspathoid with an indefinite melt point. Am
I close with that? Thanks for pointing out the extreme error and I'll try
to proofread with more accuracy. Actually, I should probably pot more and
write less.
regards, Craig Martell
Richard Aerni on thu 15 feb 01
David,
I think you have asked and answered your own question...most potters do =
not make and sell flameware because of the higher likelihood of =
liability problems. =20
Also, it seems to me, from afar, that the higher amounts of lithium in =
the clay body would limit the color palette of the glazes. I've mostly =
seen browns in use on flameware pots. Have you had a different =
experience? =20
I think I was also the person who replied that I no longer used =
casseroles...but contrary to your message, I stated that I continue to =
make them, and make them by the dozen.
Regards,
Richard Aerni
Bloomfield, NY
----- Original Message -----=20
From: David Jenkins=20
Last month there was a thread about making pots which you liked to use =
yourself. At least one person mentioned that he no longer made =
casseroles since he no longer used them himself
I am wondering why more potters don't use flameware clay, at least for =
their own personal use. I don't think I would make flameware pots and =
sell them as flameproof because of liability questions, but it is a =
great clay to use for cooking pots
Cindy Strnad on thu 15 feb 01
David J.,
I, too, would not make flameware pots and sell them, also because of the =
liability issues. In fact, having many other things to make, I don't =
currently choose to make casseroles or write "oven safe" on my tags, =
either.
However, that said, I would love to have your recipe for flameware clay. =
Would you be willing to share it?
Cindy Strnad
Earthen Vessels Pottery
RR 1, Box 51
Custer, SD 57730
USA
earthenv@gwtc.net
http://www.earthenvesselssd.com
Craig Martell on thu 15 feb 01
David sez:
>I am wondering why more potters don't use flameware clay, at least for
>their own personal use. I don't think I would make flameware pots and
>sell them as flameproof because of liability questions, but it is a great
>clay to use for cooking pots.
Hi David:
I'll try not to be too reactionary. I wouldn't use flameware for my own
use for the same reasons that I wouldn't make it to give to people I know,
or sell it to customers. It can be a very dangerous proposition. It can be
just fine too but I think potters should be keenly tuned in to lithia
ceramics and understand the materials and how to use them to make flameware
that is going to be safe for people to use.
The first thing we need to come to grips with is the nature of spodumene,
if that's our flux of choice. Spodumene is a lithium alumino silicate that
is not classed as a mineral because it doesn't have a set melting temp.
only a "range" where melt is likely to occur. This is documented in many
texts. So, if you have temperature differences in your kiln and you don't
get good fusion, several things can happen. The worst is a high percentage
of absorbtion that can cause the pot to soak up more water than is
prudent. If you subject a wet flameware pot to a hot stovetop, an
explosion could result. These pieces can also develop high levels of
cristobalite if fusion of the spodumene is incomplete. This won't lead to
pyrotechnics but will cause the pot to fail when the cristobalite inverts
at somewhere around 437 F.
I won't go into this because of the recent objection to too many lenghty
posts to Clayart but, if you want to forge ahead with flameware, look into
the properties and caveats of alpha vs. beta spodumene.
Though not many people use it because of expense, petalite is the more
reliable flux for flameware and it does have a melt temp that is
known. The problem with petalite is that it needs cone 11 to flux
properly. Lawrence and West report that there is a high failure rate in
flameware bodies fired below cone 11. It is also more difficult to fit
glazes to a flameware body and this can be very limiting to your pallete.
One thing you might want to do is fire fusion buttons of your feldspars and
the spodumene you are using and compare the two in reference to fusion
rate. Use half inch, 000, lab crucibles. If they are similar and you are
comfortable with the results you are getting with your ware, do fusions
every time you use a different bag of spodumene to ensure fusion rate is
the same, or very close. Place cones next to the fusions for temp.
verification. Also, place flameware in the hottest parts of your kiln to
ensure pieces are reaching temp.
I've typed enough so I'm outta here. That's probably my limit for the week.
regards, Craig Martell in Oregon
>The formula I used was from an article by Ron Propst in the Studio Potter
>Book published in 1978 by Studio Potter magazine. There is also a section
>on flameware in The Craft and Art of Clay by Peterson. Both of these
>sources mention glazes that fit well on flameware. I just used a
>spodumene glaze on mine since there is a high percent of spod in the clay
>body it should fit well.
>
>from David Jenkins on the coast of Maine where I have spent the last two
>days up on the roof with a shovel and ax removing snow and ice dams. Hope
>it is warm in
>Charlotte.
>
>
>
>
>
>
>
>----------
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Michael Banks on fri 16 feb 01
Craig,
I'm intrigued by this idea that spodumene is not a mineral... Four of my
mineralogy texts I regularly use are under the impression that it is a
mineral, and a well defined one at that. My texts suggest that spodumene is
actually a relatively pure phase, with limited substitution by
non-stoichiometric elements and the material is reported to form some of the
largest crystals known. Single crystals of up to forty feet in length are
well documented in some natural deposits. Funny behaviour for a non-mineral.
If not a mineral, what is it? A rock, or a mixture of phases such as
Gerstley Borate?
I'm aware that the melting points of spodumene available from ceramic supply
companies has a variable melting point, especially comparing U.S. material
with that from Western Australia, but I've always thought that this was due
to relative purity. In any event, variable melting points, do not
disqualify a material from mineral status.
Michael Banks,
Nelson,
NZ
----- Original Message -----
Craig Martell wrote:
> "Spodumene is a lithium alumino silicate that
> is not classed as a mineral because it doesn't have a set melting temp.
> only a "range" where melt is likely to occur. This is documented in many
> texts".
vince pitelka on fri 16 feb 01
David Jenkins Wrote:
" . . . . I mixed 150 lbs. of flameware clay and made a dozen =
casseroles, tureens, cooking pots to give to family/friends for =
Christmas. I kept two for myself and I have been having a great time =
using them. Just put it on the stove, turn the flame to high, and you =
are cooking! . . . . I am wondering why more potters don't use =
flameware clay, at least for their own personal use. I don't think I =
would make flameware pots and sell them as flameproof because of =
liability questions, but it is a great clay to use for cooking pots. I =
am considering using this clay for all my casseroles and baking dishes =
since it is so durable." =20
David -=20
I am always concerned when people overreact concerning safety issues, =
but it seems to me that this is one situation where a very strong =
reaction is in order. Why are you advocating this? Are you aware that =
a number of potters in the Northeast lost everything because of lawsuits =
after stove-top flameware exploded, seriously injuring the user? If you =
are using vitrified lithium-body flameware, you are really playing with =
explosives. When moisture gets impacted into the claybody, these wares =
can explode with catastrophic force, sending razor sharp shrapnel in all =
directions. Is this really something you want to risk?
If you are using porous low-fired flameware, then there is no serious =
danger. But if you are using high-fired vitrified flameware, then it is =
extremely irresponsible to be encouraging ANYONE else to make stove-top =
flameware.=20
Using this claybody for casseroles and bakers to be used in the oven =
sounds like a fine idea, but you would be wise to keep it off the =
stovetop. Sounds like you have been lucky so far, but you should not =
push your luck. =20
- Vince
Vince Pitelka=20
Appalachian Center for Crafts
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
Home - vpitelka@dtccom.net
615/597-5376
Work - wpitelka@tntech.edu
615/597-6801 ext. 111, fax 615/597-6803
http://www.craftcenter.tntech.edu/
Lili Krakowski on fri 16 feb 01
I think it was in Clay Times that someone reported on a potter who made
casseroles that were supposedly usable on the cooktop. EXPLOSION. Woman
blinded. Potter sued, literally out of house and home. NB I seem to see
fewer and fewer cooktop resistant clays in the catalogs....
Lili Krakowski
Janet Kaiser on sat 17 feb 01
Lili K. wrote:
> NB I seem to see fewer and fewer cooktop
resistant clays in the catalogs....
I guess the US potter who was sued did not have
a good defence lawyer? Or did not have the
necessary resources to sue the supplier?
Seems to me manufacturers of clay should not be
selling anything labelled "flameware" or
"stovetop" clay. It is an extremely dubious
practice and I would question their integrity as
serious clay producers.
It may be OK if it is low-fired and the end user
lives in a wood and slow cooks over (no on) an
open fire, but I cannot think of any modern-day
situation where a stove-top would not present a
danger to the pot and the user. The exception
may just be a ceramic hob on an extremely low
setting? I certainly would not want to try it
out and would not dream of recommending it to
anyone.
This has been the subject of discussion before,
but I guess it is one of those subjects which
keep reoccurring... Especially those who like to
make anything and everything out of clay... But,
we just have to accept the fact that metal,
enamelled metal or even glass (only if pans made
for the purpose by the manufacturer - for
example Pyrex) are really the best options for
cooking on the stove. They are appropriate, clay
is not.
Janet Kaiser - Snowdrops coming to an end now,
but there are aconites, primroses and
periwinkles out already and I am keeping my eyes
open for the first violets of the year. The sun
has been shining again today and the sparrows
are busy nest building under the eaves... No
wonder they are the birds of love... First to
produce a brood every year! :-)
The Chapel of Art . Capel Celfyddyd
HOME OF THE INTERNATIONAL POTTERS' PATH
Criccieth LL52 0EA, GB-Wales Tel: (01766) 523570
E-mail: postbox@the-coa.org.uk
WEBSITE: http://www.the-coa.org.uk
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