Sally Guger on thu 21 feb 08
Hello Anne, Here's my two cents worth on FB, since I've been working with many of RR's glazes and his revisions. Just yesterday, I mentioned to a friend that I like RR's Variegated Blue better than Floating Blue. I also have a revised FB that is just as nice as the GB one- maybe not always blue-(can be towards green that floats on top of dark brown- I use a pretty dark claybody) but really nice movement and variation- no pinholes so far.
The FB I have that was revised by Ron-is similar to yours but different.
Here it is:
EPK 18.6
Flint 13.0
Frit 3134 33.5
Neph Sye 27.9
RIO 1.9
Rutile 3.7
Cobalt Carb. 1.4
The Variegated Blue (also Cone 6 of course) is from Ron and John's book (MC6G). It is made from the Glossy Base Glaze 1 with the following colorants, I haven't tried any variations of these colorants. Hope this helps! Sally
RIO 3.0
Copper carb. .75
Cobalt carb. 1.0
Rutile 6.0
Anne Doyle wrote:
Dear clay buds,
I tried many of the formulas RR gave on clayart for a FB without GB last
year, but all were either too black for me or just didn't work on my clay
body. I was going to give up on this glaze completely until i tried
tweaking it...
The following formula is what i have come up with. If the kiln doesn't
overfire i get beautiful movement and great ochres on the texture with
this glaze but i still get some tiny little pinholes on some pieces. Last
firing i gave it a 5 minute soak at the end to try to smooth these over
and still tiny pinholes on some pieces, but this time the colour was
awful ... too much drab green, no longer a FB... too much heatwork...
I want to find a fix for the minor pinholes as i would like to continue to
use this glaze but i am sick of tossing pieces and time is of the essence
with a full-time job and 2 shows in June... I bisque to ^04 and fire to a
full ^6. I use PSH 519 a white stoneware for ^6.
Would you recommend something/anything easy like 1% more talc or some
whiting? I realize its a little high in alumina, thought still within
limits, is that what's causing the pinholes? what should i do from here? I
feel like i'm bumbling around in the dark with a blindfold on at this
point... i've read all the books i can find and i'm still unsure where to
go now... short of firing to ^5 with a 10 minute soak at the end, and
risquing underfiring the glazes and the ware, what else can i do?
Thank you in advance from "Desperate in Saint-Sauveur",
Anne
Recipe Name: my FB
Cone: 6 Color: multiphase blue
Firing: Oxidation Surface: Glossy
Amount Ingredient
33 Frit--Ferro 3134
30 Nepheline Syenite
17 Kaolin--EPK
16 Silica
4 Talc
100 Total
Additives
1 Cobalt Oxide
2 Iron Oxide--Red
4 Rutile
2 Bentonite
Unity Oxide
.37 Na2O
.055 K2O
.112 MgO
.463 CaO
1.000 Total
.474 Al2O3
.395 B2O3
.003 Fe2O3
3.575 SiO2
.002 TiO2
.001 P2O5
7.5 Ratio
74.5 Exp
Comments:
-----------------------------------
Calculations by GlazeMaster(tm)
www.masteringglazes.com
______________________________________________________________________________
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Live, Give, Love
Beyond All Expectation.
Sally Guger
Lakespur Blue Pottery & Sculpture
Lodi, Wisconsin, USA
http://www.saukpr.k12.wi.us/~gugersa/the_art_teachers.htm
---------------------------------
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Anne Doyle on thu 21 feb 08
Dear clay buds,
I tried many of the formulas RR gave on clayart for a FB without GB last
year, but all were either too black for me or just didn't work on my clay
body. I was going to give up on this glaze completely until i tried
tweaking it...
The following formula is what i have come up with. If the kiln doesn't
overfire i get beautiful movement and great ochres on the texture with
this glaze but i still get some tiny little pinholes on some pieces. Last
firing i gave it a 5 minute soak at the end to try to smooth these over
and still tiny pinholes on some pieces, but this time the colour was
awful ... too much drab green, no longer a FB... too much heatwork...
I want to find a fix for the minor pinholes as i would like to continue to
use this glaze but i am sick of tossing pieces and time is of the essence
with a full-time job and 2 shows in June... I bisque to ^04 and fire to a
full ^6. I use PSH 519 a white stoneware for ^6.
Would you recommend something/anything easy like 1% more talc or some
whiting? I realize its a little high in alumina, thought still within
limits, is that what's causing the pinholes? what should i do from here? I
feel like i'm bumbling around in the dark with a blindfold on at this
point... i've read all the books i can find and i'm still unsure where to
go now... short of firing to ^5 with a 10 minute soak at the end, and
risquing underfiring the glazes and the ware, what else can i do?
Thank you in advance from "Desperate in Saint-Sauveur",
Anne
Recipe Name: my FB
Cone: 6 Color: multiphase blue
Firing: Oxidation Surface: Glossy
Amount Ingredient
33 Frit--Ferro 3134
30 Nepheline Syenite
17 Kaolin--EPK
16 Silica
4 Talc
100 Total
Additives
1 Cobalt Oxide
2 Iron Oxide--Red
4 Rutile
2 Bentonite
Unity Oxide
.37 Na2O
.055 K2O
.112 MgO
.463 CaO
1.000 Total
.474 Al2O3
.395 B2O3
.003 Fe2O3
3.575 SiO2
.002 TiO2
.001 P2O5
7.5 Ratio
74.5 Exp
Comments:
-----------------------------------
Calculations by GlazeMaster=99
www.masteringglazes.com
John Post on thu 21 feb 08
Some things I would try...
Use cobalt carbonate instead of cobalt oxide. In my experience cobalt
oxide spits off a glazed pot more at cone 6 than cobalt carbonate.
Use 1.5 cobalt carb for every 1.0 grams of cobalt oxide.
Try reducing the rutile a little bit. The titanium in rutile can
cause pinholes sometimes. Try cutting the rutile in 0.5 or 1.0 gram
increments. It will be a balancing act between the color you get and
the amount of rutile in the glaze. If you are using dark rutile, you
could try light rutile. Or vice versa. US Pigment carries both kinds.
These are just a few ideas you could try. Others may have other ideas
for you.
John Post
Sterling Heights, Michigan
http://www.johnpost.us :: cone 6 glaze website ::
http://www.wemakeart.org :: elementary art website
> The following formula is what i have come up with. If the kiln doesn't
> overfire i get beautiful movement and great ochres on the texture with
> this glaze but i still get some tiny little pinholes on some pieces.
> Last
> firing i gave it a 5 minute soak at the end to try to smooth these
> over
> and still tiny pinholes on some pieces, but this time the colour was
> awful ... too much drab green, no longer a FB... too much heatwork...
>
> I want to find a fix for the minor pinholes as i would like to
> continue to
> use this glaze but i am sick of tossing pieces and time is of the
> essence
> with a full-time job and 2 shows in June... I bisque to ^04 and fire
> to a
> full ^6. I use PSH 519 a white stoneware for ^6.
Donna Kat on fri 22 feb 08
talc has caused blistering for me - it is not in the original Floating
Blue Recipe so I wonder why you have added it? Donna
Untested Non-gerstley Floating Blue
neph syenite - 35
frit 3134 - 20
frit 3195 - 12
flint - 24
epk - 8
cobalt oxide - 1
RIO - 2
Rutile - 4
Alisa Clausen on sat 23 feb 08
Hi Anne
I add the Floating Blue Colorants to many bases I test just to see if I
can nail the elusive characteristics of Floating Blue at a hard cone 6.
I have some good runner ups, but I think the best so far is Dolita Base
with the additives. You can see it and the reicpe at
http://www.flickr.com/photos/glazes/sets/ (hope I got this right now)
I also use my local Boron frit instead of G.B. in the original recipe and
that contains by weight 0.7 Barium. I get a good color response and no
pinholes. Although you have changed the original recipe considerably, you
might need to navigate completely away from it. But again, in this case,
maybe there is more in the firing to control than the recipe. It is
sensitive. On the other hand, if you want to fire as you normally with
having to give special consideration (ie a separate firing) to this glaze,
maybe a more consistent base with the same colorants will give you
Floating Blue color without the waste. I am seeing a lot of good movement
and color in the Dolita base on my clay.
Good luck,
Alisa in Denmark
Here are the Dolita analysis and the original
Recipe Name: Dolita Base (Alisa's Base)
Cone: 6 Color:
Firing: Surface: Semimatte
Amount Ingredient
27 Frit--Ferro 3134 used Frit 623
30 Kaolin--EPK
18 Silica
10 Ball Clay--Old Mine #4
15 Dolomite
100 Total
ADD
1 Cobalt Carb.,6 Rutile, 2RIO
Unity Oxide
.107 Na2O
.017 K2O
.299 MgO
.578 CaO
1.000 Total
.622 Al2O3
.2 B2O3
.009 Fe2O3
3.291 SiO2
.01 TiO2
.001 P2O5
5.3 Ratio
6 Exp
Comments:
Floating Blue, fluid
Recipe Name: Floating Blue (Blue Hare)
Cone: 6 Color:
Firing: Oxidation Surface: Glossy
Amount Ingredient
47.3 Nepheline Syenite
27 Gerstley Borate--1999 subbed with Frit 169
20.3 Silica
5.4 Kaolin--EPK
100 Total
Additives
2 Bentonite
4 Rutile
2 Iron Oxide--Red
1 Cobalt Oxide
Unity Oxide
.418 Na2O
.112 K2O
.006 MgO
.464 CaO
1.000 Total
.702 Al2O3
.476 B2O3
.002 Fe2O3
4.553 SiO2
.001 TiO2
0 P2O5
6.5 Ratio
7.3 Exp
Comments:
View alisaclausen's mapTaken in a place with no name (See more photos here)
Recipe Name: Dolita Base (Alisa's Base)
Cone: 6 Color:
Firing: Surface: Semimatte
Amount Ingredient
27 Frit--Ferro 3134 used Frit 623
30 Kaolin--EPK
18 Silica
10 Ball Clay--Old Mine #4
15 Dolomite
100 Total
ADD
1 Cobalt Carb.,6 Rutile, 2RIO
Unity Oxide
.107 Na2O
.017 K2O
.299 MgO
.578 CaO
1.000 Total
.622 Al2O3
.2 B2O3
.009 Fe2O3
3.291 SiO2
.01 TiO2
.001 P2O5
5.3 Ratio
6 Exp
Comments:
Floating Blue, fluid
Bruce Girrell on mon 25 feb 08
I have been seeing this thread go on for some time and just now finally
figured out that FB means floating blue.
On tue 22 may 07, Kathi LeSueur wrote
I opened the kiln this morning to the latest tests of a problem rutile
blue glaze. I calcined another batch of rutile and mixed up a larger
batch of the glaze. I used it on a variety of forms. None had pitting. I
made one variation in my firing. I had noticed that my red comes out
much more brilliant if I do an oxidation soak when cone 8 is just
tipping, holding the temperature for about one half hour. Since I had a
lot of red in this firing I did the soak. All of my rutile blue pieces
were good. The surface absolutely perfect.
So- now I want to test my titanium white. It has been giving me the same
problems for years and I've tried everything. I'll calcine the powder in
the bisque and try it on vases since that's the form that had the most
problems.
If anyone else is having problems with pitting on rutile blues I highly
recommend calcining the rutile. And, if it works for you let us know.
Kathi
I don't recall seeing calcining being discussed in this round. Anyone care
to give Kathi's recommendation a try?
Bruce Girrell
Ron Roy on wed 27 feb 08
Gerstley Borate has some MgO in it and the frits do not have any - so
adding a small amount of talc replaces it.
It is not normal for talc to cause blistering by the way - it is in
thousands of glaze recipes. MgO has a low expansion rate so it is very
useful in controlling crazing.
RR
>talc has caused blistering for me - it is not in the original Floating
>Blue Recipe so I wonder why you have added it? Donna
>
>Untested Non-gerstley Floating Blue
>
>neph syenite - 35
>frit 3134 - 20
>frit 3195 - 12
>flint - 24
>epk - 8
>cobalt oxide - 1
>RIO - 2
>Rutile - 4
>
>______________________________________________________________________________
>Clayart members may send postings to: clayart@lsv.ceramics.org
>
>You may look at the archives for the list, post messages, change your
>subscription settings or unsubscribe/leave the list here:
>http://www.acers.org/cic/clayart/
>
>Moderator of the list is Mel Jacobson who may be reached at melpots2@visi.com
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
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