Pancioli on tue 11 jun 02
EMU Cone 6 Stoneware Body. This one works. Not a great color, but a
little iron or Redart could help that.
EMU
Fire Clay 25
Gold Art Clay 50
Kaolin 10
Ball Clay 10
Custer Spar 12
Flint 8
Grog 10
Diana
Tom Buck on wed 12 jun 02
Diane P & Ron R:
as a followup to Diane's citation of a Cone 6 body suitable for
reduction, I sent her my recipe for same. and after reading Ron's comment,
and at D's request, I am posting this to the list.
some years back, when I was making pots for C10 R, there wasn't a
suitable light burning body in easy reach. via Clayart I connect with Meg
Levine (then in Denver area) and she graciously cited her recipe. I mixed
it and it worked fine for me.
then I switched to C6 ox (electric) at a time when a good light
burning body was hard to find (the local porcelaineous stonewares were too
short for my then-abilities on the wheel, and dried too fast for
my slabwork). I therefore adjusted Meg's body to Cone 6, made 5 separate
mixes via the slop method, and found one that was ok. here it is:
> C6 white burning (greyish) claybody (after Meg Levine)
> 48 Goldart
> 8 Old Mine #4 bc
> 12 G-200 fs
> 11 Neph sy
> 3 Talc
> 2 Wollastonite
> 16 Flint 200+ mesh
> add grog as desired.
> This body is a trifle short but is throwable, and ok for slab but
> work quickly because it tends to dry faster than a body with kaolin in
> it, and thusly develops cracks when being worked overly long.
> The mix probably could be improved by using some Hawthorn
> fireclay in place of some Goldart, and add 1%w Bentonite, dropping the
> Talc to 2%w.
> When I prepared this body I did it via Cardew's slop method
> since I do not have a mixer/pugmill. the bento would need to be slaked
> before being added ...this enhances dispersion.
Ron mentions the variability of Goldart, an observation he makes
because he undoubtedly has encountered such variations when he checks on
batches of commercial claybodies he has designed. in his case a batch
would run at least 1000 kg (a tonne or 2200 pounds), likely more. so at
48% Goldart, my claybody would require 21 bags of Goldart to make a tonne.
I would hope that Ohio Clay's practices would supply me with a fairly
uniform run of Goldart for this small quantity. But next time, as Ron
suggests, I may not get the same analysis for Goldart and I may have to
mix/test/add to get my mix as a workable claybody.
til later. Peace. Tom B.
from aa563@hwcn.org
Hamilton, Ontario, Canada.
Diana Pancioli on wed 12 jun 02
Ron Roy sent me the following message regarding the body formula I
posted yesterday:
" I would check this body out for leaking before making a lot of pots with
it.
Gold Art varies a lot as well - better to keep the percentages of such clays
lower."
My rationale for this body is that it has good working properties, most
glazes fit, and students often glaze fire their work twice. Also, Goldart
is
one of the few stoneware clays (matures at cone 9) we have to choose
from locally at a reasonable price. We can however flux the body further to
make it "tighten up", become more dense and mature. I have asked for
Ron's suggestions.
My thoughts about it are that we could leave out the kaolin (which raises
the temp), lower the fire clay amount (same thing), lower the grog,
increase the spar. ( I was putting in a number of different clays to include
various grain sizes).
I don't want to change to a softer spar because Neph Sy can become
slightly soluble and make the body flabby. I don't like talc personally. I
think it usually affects raw working time unless used sparingly. We can't
of course use GB any more and it was partly soluble anyway.
Another option could be to increase the feldspar. I was taught that this
proportion of feldspar to flint (12:8) combines to help stick the clay
particles together (Val Cushing). Perhaps I should challenge that notion
as well?
I am certainly willing to tweak the formula, but don't want to abandon it
altogether. It works in our setting and while not perfect, is pretty good
for
our purposes.
Ron, please post your reply on line. Thanks again.
Sincerely,
Diana
>EMU Cone 6 Stoneware Body. This one works. Not a great color, but a
>little iron or Redart could help that.
>
>EMU
>
>Fire Clay 25
>Gold Art Clay 50
>Kaolin 10
>Ball Clay 10
>Custer Spar 12
>Flint 8
>Grog 10
R
Lorraine Pierce on wed 12 jun 02
Diane et all...re;^6 reduction body. The following is an original body
formulated for ^9-10 reduction by Jeff Zamek and published in CM some time
ago. I tightened it up for ^6 by adding 3/4 of a pound of talc per 100
pounds dry batch weight. I add the dry mix to a barrel of water, let it
slake, mix it with a large drill with a large jiffy mixer, then sieve the
slip into a second barrel. From there it is poured into a piece of gutter
leading to the evaporation pans, and when it is ready, put thru a Venco
pugmill. Too labor intensive for many, but the most beautiful clay you can
imagine, great for my use. I am changing the formula to add more feldspar
and eliminating the talc;( Jeff's suggestion) and doubling the redart to
make a more pleasing reduction color. I am having trouble with crazing of
certain clear glazes, but not all; glazes with colorants fit. I am hoping
the body changes eliminate most glaze fit problems. Like you Diane, I have
limited clays available locally.
The recipe follows in the next post. Lori Pierce in New Port Richey,
Fl.
Lorraine Pierce on wed 12 jun 02
Original ^9-10 reduction body, Jeff Zamak, CM
G200 feldspar 7
AP Green fireclay 15
Goldart 40
Hawthorne Bond 10
Om4 ball clay 15
Redart 3
Silica 10
Grog 5
To bring the body down to ^6 Jeff increased the feldspar to 12 ;
For a warmer body color in reduction the redart could be doubled or tripled
as desired.
Brian Crocker on thu 13 jun 02
G'Day Uncle Tom,
You Canuk Potters talk funny language in your recipes, can you translate for
an Higgerent potter from the Land of Oz ?
Brian CROC.
================
----- Original Message -----
From: "Tom Buck"
To:
Sent: Thursday, June 13, 2002 1:09 PM
Subject: Re: Cone 6 Reduction Body
> Diane P & Ron R:
> as a followup to Diane's citation of a Cone 6 body suitable for
> reduction, I sent her my recipe for same. and after reading Ron's comment,
> and at D's request, I am posting this to the list.
> some years back, when I was making pots for C10 R, there wasn't a
> suitable light burning body in easy reach. via Clayart I connect with Meg
> Levine (then in Denver area) and she graciously cited her recipe. I mixed
> it and it worked fine for me.
> then I switched to C6 ox (electric) at a time when a good light
> burning body was hard to find (the local porcelaineous stonewares were too
> short for my then-abilities on the wheel, and dried too fast for
> my slabwork). I therefore adjusted Meg's body to Cone 6, made 5 separate
> mixes via the slop method, and found one that was ok. here it is:
>
> > C6 white burning (greyish) claybody (after Meg Levine)
> > 48 Goldart
> > 8 Old Mine #4 bc
> > 12 G-200 fs
> > 11 Neph sy
> > 3 Talc
> > 2 Wollastonite
> > 16 Flint 200+ mesh
> > add grog as desired.
>
> > This body is a trifle short but is throwable, and ok for slab but
> > work quickly because it tends to dry faster than a body with kaolin in
> > it, and thusly develops cracks when being worked overly long.
>
> > The mix probably could be improved by using some Hawthorn
> > fireclay in place of some Goldart, and add 1%w Bentonite, dropping the
> > Talc to 2%w.
> > When I prepared this body I did it via Cardew's slop method
> > since I do not have a mixer/pugmill. the bento would need to be slaked
> > before being added ...this enhances dispersion.
>
> Ron mentions the variability of Goldart, an observation he makes
> because he undoubtedly has encountered such variations when he checks on
> batches of commercial claybodies he has designed. in his case a batch
> would run at least 1000 kg (a tonne or 2200 pounds), likely more. so at
> 48% Goldart, my claybody would require 21 bags of Goldart to make a tonne.
> I would hope that Ohio Clay's practices would supply me with a fairly
> uniform run of Goldart for this small quantity. But next time, as Ron
> suggests, I may not get the same analysis for Goldart and I may have to
> mix/test/add to get my mix as a workable claybody.
> til later. Peace. Tom B.
>
> from aa563@hwcn.org
> Hamilton, Ontario, Canada.
>
>
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>
Ron Roy on sun 16 jun 02
I have answered Diana personally about this body but there are some issues
here that need some comment.
Neph Sy is fine - and works much better at cone 6 than the spars - it takes
a lot of spar to get melting at cone 6 unless there are other fluxes
present - like those in Red Art or similar clays.
The trick to using Neph Sy - you have to counteract the deflocclating
action of the Sodium leaching out of it - by using Epsom salts - 0.2% works
well for most clays. Just make sure it is completely dissolved in hot water
before adding it to the water you add to the dry body mix.
I have no problem with adding Talc as a melter to cone 6 bodies - it is
melting very fast at cone 6 so you need to keep an eye on it - if the Gold
Art dips in refractoriness for instance you need to make adjustments - the
only way to do that is test any new clay before you start mixing it.
As I explained to Diana - I am not so concerned with student clay - but
leaking and microwave heating are a concern and any functional ware can be
a problem.
My main concern are those potters out there trying to make a living making
functional ware - they should not use this type of body (40% GoldArt)
without testing it every time to make sure adjustments are not needed.
Kentucky Stone is another clay that varies a lot for instance - an
unblended clay. Some time it's mature at cone 6 and sometimes not - I try
to keep those types of clay to a minimum in the bodies I monitor.
RR
>" I would check this body out for leaking before making a lot of pots with it.
>Gold Art varies a lot as well - better to keep the percentages of such clays
>lower."
>
>My rationale for this body is that it has good working properties, most
>glazes fit, and students often glaze fire their work twice. Also, Goldart is
>one of the few stoneware clays (matures at cone 9) we have to choose
>from locally at a reasonable price. We can however flux the body further to
>make it "tighten up", become more dense and mature. I have asked for
>Ron's suggestions.
>
>My thoughts about it are that we could leave out the kaolin (which raises
>the temp), lower the fire clay amount (same thing), lower the grog,
>increase the spar. ( I was putting in a number of different clays to include
>various grain sizes).
>
>I don't want to change to a softer spar because Neph Sy can become
>slightly soluble and make the body flabby. I don't like talc personally. I
>think it usually affects raw working time unless used sparingly. We can't
>of course use GB any more and it was partly soluble anyway.
>
>Another option could be to increase the feldspar. I was taught that this
>proportion of feldspar to flint (12:8) combines to help stick the clay
>particles together (Val Cushing). Perhaps I should challenge that notion
>as well?
>
>I am certainly willing to tweak the formula, but don't want to abandon it
>altogether. It works in our setting and while not perfect, is pretty good for
>our purposes.
>
>Ron, please post your reply on line. Thanks again.
>
>Sincerely,
>
>Diana
>
>>EMU Cone 6 Stoneware Body. This one works. Not a great color, but a
>>little iron or Redart could help that.
>>
>>EMU
>>
>>Fire Clay 25
>>Gold Art Clay 50
>>Kaolin 10
>>Ball Clay 10
>>Custer Spar 12
>>Flint 8
>>Grog 10
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
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