Alisa Liskin Clausen on sat 16 nov 02
Glaze test for Crawl Glaze 1, cone 6-9, ox.=20
Glaze tested on white midrange stoneware fired in electric oxidation to =
1220c.
Source: Danish ceramist
Credited to:
Firing ramp:
100c p/h to 600c (212f - 1112f)
150c p/h to 1100c (330f - 2012f)=20
100c p/h to 1220c (212f - 2228f)
cool down max. per hour to 1100c=20
cool 80c per hour to 800c
shut off kiln
Recipe:
21 Manganese Carb.
57 Neph. Syenite
22 Ball Clay
Note: All raw materials are measured up or down to the nearest whole =
decimal. =20
Colorants or additives to a 100 gram test batch are measured in percent =
to the 100 gram test batch.
Substitutions: None
Results: Dry, white glaze that bubbled, but did not crawl. Application =
was thick, but may need to be beastly thick to crawl.
Smooth to the touch, with a textured surface. Oxides Cobalt, RIO, black =
stain, Chrome and Ochre showed through the glaze with straight edges as=20
painted. Chrome turned dark pinkish beige.
Regards from Alisa in Denmark
Lois Ruben Aronow on sat 16 nov 02
I'm assuming that, since this is a crawling glaze, this should read
"magnesium carb" rather than "manganese carb"
>
>Recipe:
>
>21 Manganese Carb.
>57 Neph. Syenite
>22 Ball Clay
>
>Note: All raw materials are measured up or down to the nearest whole =
decimal. =20
>Colorants or additives to a 100 gram test batch are measured in percent =
to the 100 gram test batch.
>
>Substitutions: None
>
>Results: Dry, white glaze that bubbled, but did not crawl. Application=
was thick, but may need to be beastly thick to crawl.
>Smooth to the touch, with a textured surface. Oxides Cobalt, RIO, black=
stain, Chrome and Ochre showed through the glaze with straight edges as=20
>painted. Chrome turned dark pinkish beige.
>
> Regards from Alisa in Denmark
>
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--------------------------------------------
Lois Ruben Aronow
gilois@bellatlantic.net
=46ine Craft Porcelain
http://www.loisaronow.com=20
Pat Southwood on sun 17 nov 02
Hallo,
Re; crawling glazes, if they dont crack when they dry on the pot then they
wont crawl when they fire, they need to go THICK. Watch crawl glazes on
vertical pots as they tend to either curl up and ping off onto the kiln
shelf or they just slump'n'slide to the bottom of the piece leaving a bald
patch behind them.
Try adding 20-30% MAGNESIUM carbonate NOT manganese to any glaze recipe and
see what happens, Yes Ababi, I know it shouldnt add up to more than 100, but
thats to get a sensible glaze! Crawlers are much more fun.
Also note that the size of the crawly bits will change with different
methods of application. Try using a slip trailer, pouring and brushing, but
layering it up, dont try to brush it on smoothly like an ordinary glaze
Have fun.
Pat
Pat@southwoods4. fsnet.co.uk
Alisa Liskin Clausen on mon 18 nov 02
Dear Pat,
At one time I tested a lot of my glazes with the additions of 10 - 50%
Magnesium carb. (that was a typo)
as per Ababi. They were applied and cracked to the point where they
developed fissures down to the claybody.
The brush strokes were also clearly visible in the dried glazes.
No crawling in any of them! I did get dry, drier, driest and a lot of
bubbling. After 40%, there was enough texture to make them
interesting, but not crawling like I have seen. The effect I wanted was to
look like small worms on the raw clay.
So far, I have not gotten anything to crawl. I have not really worked a lot
with them and I make vertical forms. But they
are interesting to try to achieve.
regards from Alisa
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