Judy & Howard Brager on thu 15 may 97
I recently tested the following glaze originally submitted by Barbara Webb
(in 1995).
Float Blue (Cone 5 Ox)
Neph Sy 47.3%
Gerstly Borate 27%
Silica 20.3%
EPK 5.4%
Add:
Cobalt Carb. 1%
RIO 2%
Rutile* 4%
*Dark Rutile for dark blue.
The glaze is nice but it isn't exactly what I want. It has too much brown.
Should this be applied over a white glaze to get the light blue streaks?
Any help would be appreciated.
TIA
Judy Brager (In sunny, HOT Richland, Washington USA)
The Shelfords on fri 16 may 97
Hi Judy -
I THINK the original of Floating Blue came from John Chappell's book (Clay
and Glazes for the Potter? - very similar name to the Rhodes book). The
version you posted has less cobalt than the original - I think it was 1.2%
cobalt oxide.
Re:
>The glaze is nice but it isn't exactly what I want. It has too much brown.
>Should this be applied over a white glaze to get the light blue streaks?
I use it in conjunction with a couple of other colour variations of the same
glaze, one of which uses 2.4% tin instead of the cobalt. On it's own this
is a broken tan, but over or under the Floating Blue, gives light blue
streaks, patches, etc.
The brown will always be there, unless you totally change the glaze. I
tried replacing the rutile with titanium once, and the result was less than
successful. I didn't take out the iron as well, because I liked having the
brown there. It might have possibilities, but I didn't pursue it. If you
really want a clean blue to light blue glaze, you're probably better trying
something entirely different.
Good luck!
-Veronica
____________________________________________________________________________
Veronica Shelford
e-mail: shelford@island.net
s-mail: P.O. Box 6-15
Thetis Island, BC V0R 2Y0
Tel: (250) 246-1509
____________________________________________________________________________
Roeder on fri 16 may 97
>The glaze is nice but it isn't exactly what I want. It has too much brown.
>Should this be applied over a white glaze to get the light blue streaks?
>Any help would be appreciated.
Judy,
You get brown where the glaze is thin. Use it thicker, and experiment with
multiple layers. Just don't have it too thick near the foot, in case it runs.
Also, the recipe below is originally from Chappell's book....and it is
supposed to be Cobalt OXIDE 1%. If you are using cobalt carbonate (as I do)
try doubling it (2% cobalt carb). This will help your blue along.
Using a white glaze with it will not give you light blue streaks, but a
clear plain cobalt looking blue. Loses it's depth.
The blues and lighter colors come where it is thick. Also, be sure you're
not going past cone 6, since it goes greener (a snot green) then.
Browner upon refiring as well.
Best color on porcelain, as far as blue goes. I use a light rutile-- the
book just specifies rutile (milled) so I can't tell what the dark rutile
would give you.
Good luck,
Candice Roeder
CRoeder@worldnet.att.net
In Michigan with wind chill in the twenties...refuses to be spring in this
state!!
>
>Float Blue (Cone 5 Ox)
>Neph Sy 47.3%
>Gerstly Borate 27%
>Silica 20.3%
>EPK 5.4%
>
>Add:
>Cobalt Carb. 1%
>RIO 2%
>Rutile* 4%
>*Dark Rutile for dark blue.
>
Candice Roeder
livin' in the sticks...in Michigan
CRoeder@worldnet.att.net
Jo Ann Stevens on fri 16 may 97
Hi Judy
You might want to try firing it a lower temp...I find it turns brown when I =
fire it to a cone 6...seems to be best at a cone 5...strange thing happened =
with it last year though...I over fired a kiln
load...and everything bloated and was ruined except the 2 floating blue =
bowls...and it was the most beautiful streaky dark brown......
Hope this helps
Jo Ann Stevens
http://www.geocities.com/SoHo/Lofts/2787/index.html
-----Original Message-----
From: Judy =26 Howard Brager =5BSMTP:hjbrager=40owt.com=5D
Sent: Thursday, May 15, 1997 8:48 AM
To: Multiple recipients of list CLAYART
Subject: Floating Blue (Again)
----------------------------Original message----------------------------
I recently tested the following glaze originally submitted by Barbara Webb
(in 1995).
Float Blue (Cone 5 Ox)
Neph Sy 47.3=25
Gerstly Borate 27=25
Silica 20.3=25
EPK 5.4=25
Add:
Cobalt Carb. 1=25
RIO 2=25
Rutile=2A 4=25
=2ADark Rutile for dark blue.
The glaze is nice but it isn't exactly what I want. It has too much brown.
Should this be applied over a white glaze to get the light blue streaks?
Any help would be appreciated.
TIA
Judy Brager (In sunny, HOT Richland, Washington USA)
Edward D. Cowell on sat 17 may 97
Judy: Further to my message yesterday, I was looking at your recipe and
realized that you had used 1% cobalt carb. I use 1% cobalt ox., but my
recipe indicates that you can use 1.6% cobalt carb.
Laurie Cowell,
Waterloo, Ontario.
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