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crystalline/faux celadons--update and questions

updated tue 21 nov 00

 

Fabienne Micheline Cassman on fri 17 nov 00


Hello folks, :)

I am happy to announce that I have posted the pictures of my last
crystalline glaze results on my site on a new section entitled Clay Works
if anyone is interested. Developing a glaze has been an interesting
ride. Here I am five months after my first test with one glaze that works
to my satisfaction; what a relief. Now it's just a matter of making
another one a different color :)

So, I have fired some tests with this batch, but can't figure out what
could have caused them to look so "dry." Underfired, overfired,
overfluxed, underfluxed, too thin, etc? How do I know one from the other
from just looking at the tile? I used the same base as my successful
glaze, but different colorants; what a surprise.

I also fired the faux celadons I concocted, but I'm far from thrilled at
the results. they really look "faux" and not too short of horrible imo --
I had been warned. There aren't any bubbles either which probably makes
for a great clear if I take the colorants out -- and some of you are trying
to take them out :D

Essentially, I am looking for a glaze that will not obliterate
superficially carved design but enhance it. I was wondering if
brushing/sponging a light coat of copper oxide with water, then slap a
clear on top of it would do the trick. I am looking for an even
look/application. Any comments would be greatly appreciated.

TIA,

Faye

PS I am also renewing my offer for the virtual gallery if anyone is
interested. Check it out.
--
Milky Way Ceramics http://www.milkywayceramics.com/

Yes, I have learned from my mistakes...
I can reproduce them exactly.

Brad Sondahl on sat 18 nov 00


When crystalline glazes appear dry, they are underfired, producing small
crystals and a matte appearance. Unless you put cone packs on every
level of your kiln, you can easily have 2-3 cone differences in temp, so
you will get varied results. You will do better having all your tests
on one level, preferably by the kilnsitter or thermocouple, but even
peepholes or other leaks can vary the temp on a shelf. Also with tiles
one tends to use short posts of an inch or less, which also causes
underfiring.
Have you viewed my short guide to crystalline glazes?

--
Brad Sondahl
New Homepage: http://pages.about.com/bsondahl/index.html
New commercial pottery page http://sondahl.safeshopper.com
Original literature, music, pottery, and art

Joyce Lee on sat 18 nov 00


ok

Fabienne Micheline Cassman wrote:
>
> Hello folks, :)
>
> I am happy to announce that I have posted the pictures of my last
> crystalline glaze results on my site on a new section entitled Clay Works
> if anyone is interested. Developing a glaze has been an interesting
> ride. Here I am five months after my first test with one glaze that works
> to my satisfaction; what a relief. Now it's just a matter of making
> another one a different color :)
>
> So, I have fired some tests with this batch, but can't figure out what
> could have caused them to look so "dry." Underfired, overfired,
> overfluxed, underfluxed, too thin, etc? How do I know one from the other
> from just looking at the tile? I used the same base as my successful
> glaze, but different colorants; what a surprise.
>
> I also fired the faux celadons I concocted, but I'm far from thrilled at
> the results. they really look "faux" and not too short of horrible imo --
> I had been warned. There aren't any bubbles either which probably makes
> for a great clear if I take the colorants out -- and some of you are trying
> to take them out :D
>
> Essentially, I am looking for a glaze that will not obliterate
> superficially carved design but enhance it. I was wondering if
> brushing/sponging a light coat of copper oxide with water, then slap a
> clear on top of it would do the trick. I am looking for an even
> look/application. Any comments would be greatly appreciated.
>
> TIA,
>
> Faye
>
> PS I am also renewing my offer for the virtual gallery if anyone is
> interested. Check it out.
> --
> Milky Way Ceramics http://www.milkywayceramics.com/
>
> Yes, I have learned from my mistakes...
> I can reproduce them exactly.
>
> ______________________________________________________________________________
> 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.

Ababi Sharon on sat 18 nov 00


Hello Faye,
Your tests are beautifull!
Now let us see if I understood you: Do you ask if you can draw lines with
oxides under the crystalline glaze?
Diane Creber , in her book writes something about pre painting of the piece
with oxides/stains.
I tested "My" base, without oxides. A) Sprinkled like salt dry oxides B)
Sprinkled wet oxides.
worked, but I did not like the results. The wet was better.
The surprise:Beautifull as CLEAR without any colorant!
Back to your question, it might be very interesting if you do it with
concentrated oxide, from a colorant that goes well with your base glaze, on
white background.
Ababi Sharon
ababisharon@hotmail.com
http://www.milkywayceramics.com/cgallery/asharon.htm
http://www.israelceramics.org/index.html
* * * * * * * *
www.photoisland.com
ID: sharon@shoval.org.il
Password:clay



----- Original Message -----
From: "Fabienne Micheline Cassman"
To:
Sent: Saturday, November 18, 2000 4:44 AM
Subject: Crystalline/Faux Celadons--Update and Questions


> Hello folks, :)
>
> I am happy to announce that I have posted the pictures of my last
> crystalline glaze results on my site on a new section entitled Clay Works
> if anyone is interested. Developing a glaze has been an interesting
> ride. Here I am five months after my first test with one glaze that works
> to my satisfaction; what a relief. Now it's just a matter of making
> another one a different color :)
>
> So, I have fired some tests with this batch, but can't figure out what
> could have caused them to look so "dry." Underfired, overfired,
> overfluxed, underfluxed, too thin, etc? How do I know one from the other
> from just looking at the tile? I used the same base as my successful
> glaze, but different colorants; what a surprise.
>
> I also fired the faux celadons I concocted, but I'm far from thrilled at
> the results. they really look "faux" and not too short of horrible imo --
> I had been warned. There aren't any bubbles either which probably makes
> for a great clear if I take the colorants out -- and some of you are
trying
> to take them out :D
>
> Essentially, I am looking for a glaze that will not obliterate
> superficially carved design but enhance it. I was wondering if
> brushing/sponging a light coat of copper oxide with water, then slap a
> clear on top of it would do the trick. I am looking for an even
> look/application. Any comments would be greatly appreciated.
>
> TIA,
>
> Faye
>
> PS I am also renewing my offer for the virtual gallery if anyone is
> interested. Check it out.
> --
> Milky Way Ceramics http://www.milkywayceramics.com/
>
> Yes, I have learned from my mistakes...
> I can reproduce them exactly.
>
>
____________________________________________________________________________
__
> 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.
>

Wade Blocker on sat 18 nov 00


Fabienne,
Mix some copper carbonate with water, brush it on your ware, Wear
disposable gloves and with a damp sponge that you frequently rinse in
clean water, wipe off the oxide stain except in the depressions where you
want it to stay. When dry, cover with a transparent glaze.You might also
try a green stain instead of the copper carb. Hope this will work for you.
Mia in ABQ

Fabienne Micheline Cassman on mon 20 nov 00


Thank you for the advice/help.

I will try a wash and a clear since all of those who e-mailed agree that it
works.

In term of crystalline glazes, what puzzled me was that the tests might
have been underfired which is now confirmed. The firing was even from top
to bottom as per the cone packs. However, it was the same base I used for
my larger plates in the same firing and it was more than successful, i.e.
completely covered with crystals :) After a few days of pulling my hair
out (I have a lot of them ;)), I realized that I had cut down the colorants
considerably and thus potential fluxes. That could explain it. I will
adjust the recipe accordingly and run tests.

Thank you again,

Fabienne
--
Milky Way Ceramics http://www.milkywayceramics.com/

Yes, I have learned from my mistakes...
I can reproduce them exactly.