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glaze test for wodo white, cone 6, oxidation.

updated fri 30 mar 01

 

Alisa og Claus Clausen on tue 20 feb 01


Source: Original Dolomite White receipe from T. Martens, South Africa.

Tested on light light tan, mid range stoneware, fired to cone 6, =
oxidation.

Receipe:
49 Neph. Sye.
25 Dolomite
6 Wollastonite
20 Ball Clay

Resulted in a white, semi matt, waxy, covering glaze. Stable and very =
smooth to the touch. The painted mix of colbalt, rutile and ball clay =
on top of the glaze gave undefined edges, and a nice play of blue lines =
spotted with the rutile. No cobalt greens like on the orginal Dolomite =
receipe, but may need a bigger testing surface.


The original receipe (ToDo White)called for=20
50 Neph. Sye.=20
5 Whiting.
It is also a good glaze, but more off white in color and a softer, matt =
surface that is not scratch resistant.

This slight adjustment with Wollastonite, produced a more scratch =
resistant surface, but not completly hard liker a higher gloss glaze. I =
am personally happy for this adjustment, as it gives me a replacement =
glaze for the Waxy White that is not working for me at the time. =20

Best regards,
Alisa in Denmark

Ababi on thu 29 mar 01


Here is the original letter. mine follows it.
----- Original Message -----
From: "Alisa og Claus Clausen"
To:
Sent: Tuesday, February 20, 2001 6:53 PM
Subject: Glaze test for WoDo White, cone 6, oxidation.


Source: Original Dolomite White receipe from T. Martens, South Africa.

Tested on light light tan, mid range stoneware, fired to cone 6, oxidation.

Receipe:
49 Neph. Sye.
25 Dolomite
6 Wollastonite
20 Ball Clay

Resulted in a white, semi matt, waxy, covering glaze. Stable and very
smooth to the touch. The painted mix of colbalt, rutile and ball clay on
top of the glaze gave undefined edges, and a nice play of blue lines spotted
with the rutile. No cobalt greens like on the orginal Dolomite receipe, but
may need a bigger testing surface.


The original receipe (ToDo White)called for
50 Neph. Sye.
5 Whiting.
It is also a good glaze, but more off white in color and a softer, matt
surface that is not scratch resistant.

This slight adjustment with Wollastonite, produced a more scratch resistant
surface, but not completly hard liker a higher gloss glaze. I am personally
happy for this adjustment, as it gives me a replacement glaze for the Waxy
White that is not working for me at the time.

Best regards,
Alisa in Denmark

____________________________________________________________________________
__

----- Original Message -----
From: "Ababi"
To:
Sent: Wednesday, March 28, 2001 2:42 PM
Subject: "recipe or formula" Manipulating!!!


> About a month ago Alisa sent a recipe of white glaze that she slightly
> changed.
> About a week ago we had a thread "recipe or formula" I did not join it, I
> think it is good to have both to get the nearest results.Here is the
> original Recipe:
>
> WoDo White, cone 6, oxidation
================================
> NEPHELINE SYENITE... 49.00 49.00%
> DOLOMITE............ 25.00 25.00%
> WOLLASTONITE........ 6.00 6.00%
> BALL CLAY (AK)...... 20.00 20.00%
> ========
> 100.00
>
> CaO 0.43* 12.51%
> MgO 0.33* 6.92%
> K2O 0.06* 2.82%
> Na2O 0.19* 6.08%
> TiO2 0.00 0.02%
> Al2O3 0.40 21.24%
> SiO2 1.59 50.11%
> Fe2O3 0.00 0.28%
>
>
> Si:Al 4.00
> SiB:Al 4.00
> Expan 8.45
>
> I liked some of the materials I could use instead of the original ones
which
> I have actually, and manipulated the recipe:
>
> waxy half clear
> =================
> WOLLASTONITE........ 20.07 20.07%
> BALL CLAY (AK)...... 40.03 40.03%
> MAGNESIUM CARBONATE. 10.70 10.70%
> CRYOLITE............ 20.76 20.76%
> QUARTZ.............. 8.45 8.45%
> ========
> 100.00
>
> CaO 0.43* 12.60%
> MgO 0.33* 6.98%
> K2O 0.00* 0.16%
> Na2O 0.24* 7.84%
> SrO 0.00* 0.03%
> TiO2 0.00 0.05%
> Al2O3 0.40 21.38%
> SiO2 1.59 50.44%
> Fe2O3 0.01 0.52%
>
>
> Si:Al 4.00
> SiB:Al 4.00
> Expan 8.32
>
> The manipulating from my point of view was using Cryoilite a very
surprising
> material (of coarse Na2O instead of K2O)
> Magnesium carbonate instead of dolomite
> And, when ever I use more than 30% clay , the extra I calcin, this time I
> have used it as it is.
> I hoped to get some kind of crawling or almost crawling glaze. The result
is
> kind of waxy, glaze.you can see it in my utility page (in my humble site)
>

Ababi Sharon
ababisha@shoval.ardom.co.il
http://members4.clubphoto.com/ababi306910/