Bill Amsterlaw on sun 16 feb 97
Hi Lee:
What do you do with your warm Soda Ash solution?
Lee Love said:
>>I was under the impression that this was a commercial crock pot liner that
broke. I had one break too, one I picked up at the GoodWill to warm my Soda
Ash solution... <<
- Bill Amsterlaw
Plattsburgh, NY
Akita-jin \"Lee Love\" on mon 17 feb 97
On Sun, 16 Feb 1997 11:47:53 EST Bill Amsterlaw writes:
>
>Hi Lee:
>
>What do you do with your warm Soda Ash solution?
Most often, I use it to paint onto pots before I put Shino, Chun
or ash glazes on (glazes with soluables in them.) You have to be
careful on stoneware because on the bare areas it will make the surface a
little ruff (it is ok if that is what you are trying to get, of course.)
You can also brush or spray it on top of glazes. This allows you to
control carbon trapping (it will appear where you brush or spray only,
especially if you don't put the soda ash in the glaze.)
Another cool decoration technique is to use wax resisted over a
high soda ash shino, right after you glaze (you can do this with double
coats of glaze too. Where the resist is applied, you will not have
carbon trapping but it will be heaviest at where the edge of where the
resist is. You can decorate this way. You can also wax resist and
then brush soda ash over it. These applications seem to help ash stick
to pots in wood firing too.
Calgon water seems to work best on bare stoneware for toasting up
the claybody in gas reduction (better than soda ash.) Soda ash on
kaolin bodies (low iron) gives some nice results.
Lee
/(o\ Lee Love In St. Paul, MN Come see some pixs of my AkitaPup:
\o)/ mailto:Ikiru@juno.com http://www.millcomm.com/~leelove
LeeLove@millcomm.com "You can observe a lot by watching."
.. -Yogi Berra-
Bill Amsterlaw on tue 18 feb 97
Hi Lee:
Thank you for sharing the information on soda ash (and Calgon).
I have been trying to guess at why soda ash and Calgon have the effects you
describe. Soda ash is sodium carbonate and calgon is sodium hexa-meta
phosphate. My best guess is that the sodium in these compounds is causing
local increased fluxing. According to this guess, the treated areas would form
a glass at a temperature at which carbon is still burning off. These glassy
treated areas would form a barrier which traps carbon while the surrounding
untreated areas are still porous enough to allow carbon to escape. If this
guess is correct, table salt should work just as well as soda ash or calgon.
I hope some people with a better understanding of these phenomena will comment
on this.
- Bill Amsterlaw
Plattsburgh, NY
----
On 17 Feb 1997 Lee Love wrote:
>>
Most often, I use it [warm Soda Ash solution] to paint onto pots before I put
Shino, Chun or ash glazes on (glazes with solubles in them.) You have to be
careful on stoneware because on the bare areas it will make the surface a
little rough (it is ok if that is what you are trying to get, of course.)
You can also brush or spray it on top of glazes. This allows you to control
carbon trapping ([carbon trapping] will appear where you brush or spray only,
especially if you don't put the soda ash in the glaze.)
Another cool decoration technique is to use wax resisted over a high soda ash
shino, right after you glaze (you can do this with double coats of glaze too).
Where the resist is applied, you will not have carbon trapping but it will be
heaviest at the edge of where the resist is. You can decorate this way. You
can also wax resist and then brush soda ash over it. These applications seem
to help ash stick to pots in wood firing too.
Calgon water seems to work best on bare stoneware for toasting up the claybody
in gas reduction (better than soda ash.) Soda ash on kaolin bodies (low iron)
gives some nice results.
<<
Akita-jin \"Lee Love\" on tue 18 feb 97
Hi Bill,
The other aspect is that these are solubles that bring oxides in
the claybody into suspension and deposits them on top of the glaze
surface as the glaze drys.
Table salt, sodium bicarbonate and other solubles (including wood
ash) will do similar things, but the final results are all different.
The Calgon seems to be less harsh on an iron bearing clay body, that is
why it leaves a warm but not ruff surface (this works well on bean pots
that you leave unglazed on the outside. Gives you a toasty surface.)
Soda Ash leaves an iron bearing claybody ruff, when it is used on bare
clay. On soaked porcelain, it looks like a salt firing. I've used a
table salt shino, but I think they require a longer firing time than the
soda ash shinos.
Also, the soda ash fluxes at a low temperature, around ^012, and
this helps surfaces hold on to ash in a woodfiring.
Lee
/(o\ Lee Love In St. Paul, MN Come see some pixs of my AkitaPup:
\o)/ mailto:Ikiru@juno.com http://www.millcomm.com/~leelove
LeeLove@millcomm.com "You can observe a lot by watching."
.. -Yogi Berra-
On Tue, 18 Feb 97 13:36:44 UT "Bill Amsterlaw" writes:
> Soda ash is sodium carbonate and calgon is sodium hexa-meta
>phosphate. My best guess is that the sodium in these compounds is
>causing local increased fluxing. According to this guess, the treated
areas
>would form a glass at a temperature at which carbon is still burning
off.
>These glassy treated areas would form a barrier which traps carbon while
the surrounding untreated areas are still porous enough to allow carbon
to escape.
> If this guess is correct, table salt should work just as well as soda
ash or
>calgon.
Louis Katz on wed 19 feb 97
Bill Amsterlaw wrote:
>
> ----------------------------Original message----------------------------
> Hi Lee:
>
> Thank you for sharing the information on soda ash (and Calgon).
>
> I have been trying to guess at why soda ash and Calgon have the effects you
> describe. Soda ash is sodium carbonate and calgon is sodium hexa-meta
> phosphate. My best guess is that the sodium in these compounds is causing
> local increased fluxing. According to this guess, the treated areas would form
Old Calgon used to be Sodium Hexa Meta Phosphate, new Calgon in most
places is mostly soda ash. New Calgon Boxes are marked with a product
code somewhere that indicates if the product has phsophate in it.
Louis
--
Louis Katz lkatz@falcon.tamucc.edu
Texas A&M University Corpus Christi
6300 Ocean
CCTX 78412
(512) 994-5987
http://www.tamucc.edu/~lkatz
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