Rick Mace on sat 16 aug 97
I've been bisque firing different cone 10 clays to cone 2 (not 02) and then
raku firing them. So I call it raku stoneware. I'm very thrilled by the
results in that, for one thing, the pieces are water tight. They also ring
when you tap them instead of going "thud." It was predicted that such a
high bisque would prevent the clay from turning black ... and that is
somewhat true... Anyone else have experience with high firing ware before
raku firing?
A big problem is thermal shock and I've "lost" quite a few pieces. I put
lost in quotes because I've started carefully breaking the pieces that
break, smoking the pieces in a fire and then glueing them back together
with elmers glue. I've also re-raku fired the individual pieces before
re-glueing the whole piece back together, and that is also interesting. I'm
going to try sealing the glued vases on the inside with poly... poly...
what is that stuff... it's two parts, anyway, it's like an epoxy resin only
cheaper.
Does anyone have hints or suggestions on such a process? ...oh, it's poly
ester resin... I think!
Rick mace
http://shell.rmi.net/~rmace/
Akitajin \"Lee Love\" on sun 17 aug 97
Ric Mace,
I have found that quenching pieces in water is the main thing
that makes the glaze porous. If you just put the work in the reduction
material and then let them cool they will hold water better.
~
Lee in St. Paul, Minnesota U.S.A.
http://www.millcomm.com/~leelove/ikiru.html Come see my pottery.
F. Melville on sun 17 aug 97
------------------
Rick,
Yes, I have been bisque-firing my raku to 1150 C=BA or so for the
past two years and I too prefer the feel and sound of the end result. I do
not guarantee vases to be 100=25 waterproof over time, but they seem OK when
tested over a week of holding flowers. When I bisque =5E6 porcelain for =
raku,
I sometimes go as high as =5E4 if the piece is narrow-based and very thin.
Francoise
F. Melville
Indalo Pottery
P.O. Box 95
Port Edward, B.C.
Canada V0V 1G0
Email:fmelvill=40mail.kaien.com
http://members.tripod.com/=7Eindalopottery
Andrew & Laura Conley on mon 18 aug 97
I once raku fired (approx cone 1 at my studio) some overfired bisqued
pots (cone 5 instead of 05) and they were fine except they were not as
black. I never checked for water-tighntess.
I expect that the qualities ring vs tap and water tightness are at odds
with clay turning black. The clay turning black probably has to do with
the maturity and openess of the clay, not the exact temperature that it
has been bisqued at. Have you experimented with cones 01, 00 and 1 to
see if the qualities at these temps are better overall?
I have wondered about glaze firing pieces to a high temp and then
applying raku glazes to some areas and raku firing at a low temp. Has
anyone tried this? Are these pieces water-tight? Is the high-fire
glaze relatively intact? Will reduced high fire glazes reoxidize at
normal raku temps?
Rick Mace wrote:
>
> ----------------------------Original message----------------------------
> I've been bisque firing different cone 10 clays to cone 2 (not 02) and then
> raku firing them. So I call it raku stoneware. I'm very thrilled by the
> results in that, for one thing, the pieces are water tight. They also ring
> when you tap them instead of going "thud." It was predicted that such a
> high bisque would prevent the clay from turning black ... and that is
> somewhat true... Anyone else have experience with high firing ware before
> raku firing?
>
> A big problem is thermal shock and I've "lost" quite a few pieces. I put
> lost in quotes because I've started carefully breaking the pieces that
> break, smoking the pieces in a fire and then glueing them back together
> with elmers glue. I've also re-raku fired the individual pieces before
> re-glueing the whole piece back together, and that is also interesting. I'm
> going to try sealing the glued vases on the inside with poly... poly...
> what is that stuff... it's two parts, anyway, it's like an epoxy resin only
> cheaper.
>
> Does anyone have hints or suggestions on such a process? ...oh, it's poly
> ester resin... I think!
>
> Rick mace
> http://shell.rmi.net/~rmace/
"WNTHRP::MRGATE::\"A1::CONNELLJ\""@winthrop.edu on mon 18 aug 97
While dousing your pot will definitely have an effect if whether your raku ware
can hold water, it is not a question of porosity but rather all about cracking
the piece due to extreme thermal shock. I successfully fire my raku a number of
times and I attribute that ability to a number of things. Luck is always at the
top but good clay and letting the pieces cool down in the can until they are
cool to the touch are probably the most important.
Raku grew around a myth that you had to do it a certain way (i.e. Soldner's way)
and as we all know, Soldner had no idea what to do the first time he attempted
the process. Dunking your piece in water developed in the beginning and has
persisted up until the present time. I'm not saying dunking is all that bad.
It obvious has some advantages (freezing the reduction) but it also has some
problems. Cracking the ware being the number one problem.
The point I want to make is that raku is all about experimenting and finding
your own way. Start off by doing it someone else's way but don't be afraid to
try something new. With a basis knowledge of glaze chemistry and a basic
knowledge of fire and the effects of heat you can do some neat things.
I have experimented with raku firing some cone 10 pieces with varying luck.
It is hell on the body but the glazes improved. I'm not sold on it but it was a
neat experiment for a while.
Remember, in art, the number one rule is that there are no rules!
Jim Connell
Winthrop University
SC
terry hagiwara on mon 18 aug 97
you can raku-fire cone 10 high fired pieces. they are not porous and
less heat resilient. so, you fire them up more slowly in the beginning.
(this is one way how i salvage miserably executed high fire glazed
pieces if their shapes are agreeable with the raku glazes i like.) you
can always go down to lower-temperature glazes. terry
Lee Love on wed 20 aug 97
Jim,
I agree. Quenching in water is not a traditional raku
technique.
Lee in St. Paul
On Mon, 18 Aug 1997 23:43:07 EDT
"WNTHRP::MRGATE::\"A1::CONNELLJ\""@winthrop.edu writes:
>Raku grew around a myth that you had to do it a certain way (i.e.
>Soldner's way) and as we all know, Soldner had no idea what to do
> the first time he attempted the process. Dunking your piece in water
>developed in the beginning and has persisted up until the present time.
>I'm not saying dunking is all that bad.
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