search  current discussion  categories  glazes - cone 4-7 

cone 6 satin matte/semi-gloss

updated mon 22 nov 99

 

Chris Schafale on sat 13 nov 99

For all you cone 6 electric folk, here's a glaze I've been
working on recently that you may like to try. Applied thin
and without opacifiers or colorants, it is quite transparent, and has
a very pleasant satin-matte texture. I've been firing it to a full
cone 6 (which I define as cone 5 flat, cone 6 fully arched to the
level of the base), with a bit of a fire-down (100 degrees C per hour
down to 900 C). I think it will be good over underglaze designs,
though I haven't tested it extensively yet. I'm working on
colorants, see comments below. The recipe is:

Candle Satin Matte

====================
G 200 FELDSPAR...... 42.00
Frit 3124........... 19.00
TALC................ 9.00
DOLOMITE............ 9.00
EPK................. 15.00
SILICA.............. 6.00
========
100.00

CaO 0.33* 6.20%
MgO 0.39* 5.37%
K2O 0.16* 4.99%
Na2O 0.13* 2.67%
TiO2 0.01 0.23%
Al2O3 0.48 16.48%
B2O3 0.12 2.78%
SiO2 3.00 61.19%
Fe2O3 0.00 0.11%

Cost/lb 0.64
Si:Al 6.30
SiB:Al 6.55
Expan 7.05

Colorants/Opacifiers:
Note: I use mostly brown and red-brown clays. This glaze really
needs opacifiers to help the colors come out on darker clay bodies
-- my first tests with cobalt and no opacifier showed almost no blue
at all. On a lighter clay (Miller/Laguna 50), though, colorants
without opacifier made very nice soft colors (reminded me of the
Outer Banks). I haven't tried it on white clays. The following
results are based on brown clays:

5% Zircopax makes a semi-opaque glaze that allows some of the body
color to show through. 10% Zircopax makes white.

3% tin makes a nice white, not completely opaque

3% tin plus 0.5-2% cobalt carbonate makes soft blues (I thought I'd
get purples with all that magnesia -- anyone know why not?)

3% tin plus 4-8% rutile makes soft yellows (oddly, to me, the yellows
were much paler on the darker clays, much nicer -- more gold -- on
the Miller 50)

And my favorite:

3% tin plus 2% Red Iron Oxide makes a light tan that breaks
beautifully to rust brown on edges, throwing ridges, etc. Again a
fairly thin coat of glaze works best. Thicker application
makes more of a cream-tan.

3% tin plus 4% RIO gives a lovely bright rust.

More iron makes a deep brown with reddish undertones (does not get
redder with refiring).

This glaze apparently is teetering on the brink of being satin-matte
or semi-gloss. Additions of tin and colorants definitely pushed it
in the direction of gloss, with some of the variations being quite
glossy.

Happy testing!

Chris
Light One Candle Pottery
Fuquay-Varina, NC
candle@intrex.net

Carenza Hayhoe on mon 15 nov 99

I have been trying to formulate the perfect transparent satin matte ^6 glaze
for years. I would love to try this semi-gloss, satin-matte but UK raw
materials are different. Would it be possible to have the formulae?
Carenza
http://www.mochaware.com
----- Original Message -----
From: Chris Schafale
To:
Sent: Sunday, November 14, 1999 4:38 AM
Subject: Cone 6 satin matte/semi-gloss


> ----------------------------Original message----------------------------
> For all you cone 6 electric folk, here's a glaze I've been
> working on recently that you may like to try. Applied thin
> and without opacifiers or colorants, it is quite transparent, and has
> a very pleasant satin-matte texture. I've been firing it to a full
> cone 6 (which I define as cone 5 flat, cone 6 fully arched to the
> level of the base), with a bit of a fire-down (100 degrees C per hour
> down to 900 C). I think it will be good over underglaze designs,
> though I haven't tested it extensively yet. I'm working on
> colorants, see comments below. The recipe is:
>
> Candle Satin Matte
>
> ====================
> G 200 FELDSPAR...... 42.00
> Frit 3124........... 19.00
> TALC................ 9.00
> DOLOMITE............ 9.00
> EPK................. 15.00
> SILICA.............. 6.00
> ========
> 100.00
>
> CaO 0.33* 6.20%
> MgO 0.39* 5.37%
> K2O 0.16* 4.99%
> Na2O 0.13* 2.67%
> TiO2 0.01 0.23%
> Al2O3 0.48 16.48%
> B2O3 0.12 2.78%
> SiO2 3.00 61.19%
> Fe2O3 0.00 0.11%
>
> Cost/lb 0.64
> Si:Al 6.30
> SiB:Al 6.55
> Expan 7.05
>
> Colorants/Opacifiers:
> Note: I use mostly brown and red-brown clays. This glaze really
> needs opacifiers to help the colors come out on darker clay bodies
> -- my first tests with cobalt and no opacifier showed almost no blue
> at all. On a lighter clay (Miller/Laguna 50), though, colorants
> without opacifier made very nice soft colors (reminded me of the
> Outer Banks). I haven't tried it on white clays. The following
> results are based on brown clays:
>
> 5% Zircopax makes a semi-opaque glaze that allows some of the body
> color to show through. 10% Zircopax makes white.
>
> 3% tin makes a nice white, not completely opaque
>
> 3% tin plus 0.5-2% cobalt carbonate makes soft blues (I thought I'd
> get purples with all that magnesia -- anyone know why not?)
>
> 3% tin plus 4-8% rutile makes soft yellows (oddly, to me, the yellows
> were much paler on the darker clays, much nicer -- more gold -- on
> the Miller 50)
>
> And my favorite:
>
> 3% tin plus 2% Red Iron Oxide makes a light tan that breaks
> beautifully to rust brown on edges, throwing ridges, etc. Again a
> fairly thin coat of glaze works best. Thicker application
> makes more of a cream-tan.
>
> 3% tin plus 4% RIO gives a lovely bright rust.
>
> More iron makes a deep brown with reddish undertones (does not get
> redder with refiring).
>
> This glaze apparently is teetering on the brink of being satin-matte
> or semi-gloss. Additions of tin and colorants definitely pushed it
> in the direction of gloss, with some of the variations being quite
> glossy.
>
> Happy testing!
>
> Chris
> Light One Candle Pottery
> Fuquay-Varina, NC
> candle@intrex.net
>
>

Cindy Strnad, Earthen Vessels Pottery on mon 15 nov 99

Chris,

Thanks for sharing your recipe. I want to try it--not sure if I have any G
200 spar on hand, but that's easy to fix. The thing I'm wondering about is
the tin. Is it necessary for some chemical reason, or aesthetic reason, or
is that just what you happened to test with, or what? I notice you do use
zircopax for the white. Don't mind shelling out the bucks if there's a
beautiful glaze out there that needs the best, but don't like to be
wasteful, either.

Curious (and--okay--cheap, too)

Cindy Strnad
Earthen Vessels Pottery
Custer, SD

Chris Schafale on tue 16 nov 99

Cindy,

Actually, I don't know if the tin is necessary -- I was just
experimenting because I hadn't used it before. The other glazes that
I've seen with that "breaking-red" quality did have tin in them,
though.... Maybe others can comment on this. I liked the results
from the tin -- a kind of creamy smoothness in addition to the
opacity -- and I found that I needed about two to three times as much
zircopax to get the same amount of opacification. If you try it with
zircopax, let us know how it turns out. And I think Custer spar
would do just fine -- I use G200 because it's mined here in the
southeast.

Chris

> ----------------------------Original message----------------------------
> Chris,
>
> Thanks for sharing your recipe. I want to try it--not sure if I have any G
> 200 spar on hand, but that's easy to fix. The thing I'm wondering about is
> the tin. Is it necessary for some chemical reason, or aesthetic reason, or
> is that just what you happened to test with, or what? I notice you do use
> zircopax for the white. Don't mind shelling out the bucks if there's a
> beautiful glaze out there that needs the best, but don't like to be
> wasteful, either.
>
> Curious (and--okay--cheap, too)
>
> Cindy Strnad
> Earthen Vessels Pottery
> Custer, SD
>
>
Light One Candle Pottery
Fuquay-Varina, NC
candle@intrex.net

Chris Schafale on sat 20 nov 99

Carenza,

I was hoping someone with more technical knowhow would address this,
but I'll give it a shot.

G-200 is a potash feldspar, analysis from Insight is:

CaO 0.01 0.82%
MgO 0.00 0.05%
K2O 0.11 10.80%
Na2O 0.05 3.05%
Al2O3 0.18 18.58%
SiO2 1.11 66.61%
Fe2O3 0.00 0.09%

Ferro Frit 3124 is:

CaO 0.25 14.09%
K2O 0.01 0.71%
Na2O 0.10 6.30%
Al2O3 0.10 9.89%
B2O3 0.20 13.70%
SiO2 0.92 55.30%

EPK is Edgar Plastic Kaolin, a china clay:

CaO 0.00 0.22%
MgO 0.00 0.12%
K2O 0.00 0.41%
Na2O 0.00 0.08%
TiO2 0.00 0.45%
Al2O3 0.37 43.86%
P2O5 0.00 0.31%
SiO2 0.77 53.67%
Fe2O3 0.00 0.89%

I assume you have talc, dolomite, and silica (flint) -- I use 325
mesh).

Hope this gives you what you need. Good luck.

Chris

> ----------------------------Original message----------------------------
> I have been trying to formulate the perfect transparent satin matte ^6 glaze
> for years. I would love to try this semi-gloss, satin-matte but UK raw
> materials are different. Would it be possible to have the formulae?
> Carenza
> http://www.mochaware.com
> ----- Original Message -----
> From: Chris Schafale
> To:
> Sent: Sunday, November 14, 1999 4:38 AM
> Subject: Cone 6 satin matte/semi-gloss
>
>
> > ----------------------------Original message----------------------------
> > For all you cone 6 electric folk, here's a glaze I've been
> > working on recently that you may like to try. Applied thin
> > and without opacifiers or colorants, it is quite transparent, and has
> > a very pleasant satin-matte texture. I've been firing it to a full
> > cone 6 (which I define as cone 5 flat, cone 6 fully arched to the
> > level of the base), with a bit of a fire-down (100 degrees C per hour
> > down to 900 C). I think it will be good over underglaze designs,
> > though I haven't tested it extensively yet. I'm working on
> > colorants, see comments below. The recipe is:
> >
> > Candle Satin Matte
> >
> > ====================
> > G 200 FELDSPAR...... 42.00
> > Frit 3124........... 19.00
> > TALC................ 9.00
> > DOLOMITE............ 9.00
> > EPK................. 15.00
> > SILICA.............. 6.00
> > ========
> > 100.00
> >
> > CaO 0.33* 6.20%
> > MgO 0.39* 5.37%
> > K2O 0.16* 4.99%
> > Na2O 0.13* 2.67%
> > TiO2 0.01 0.23%
> > Al2O3 0.48 16.48%
> > B2O3 0.12 2.78%
> > SiO2 3.00 61.19%
> > Fe2O3 0.00 0.11%
> >
> > Cost/lb 0.64
> > Si:Al 6.30
> > SiB:Al 6.55
> > Expan 7.05
> >
> > Colorants/Opacifiers:
> > Note: I use mostly brown and red-brown clays. This glaze really
> > needs opacifiers to help the colors come out on darker clay bodies
> > -- my first tests with cobalt and no opacifier showed almost no blue
> > at all. On a lighter clay (Miller/Laguna 50), though, colorants
> > without opacifier made very nice soft colors (reminded me of the
> > Outer Banks). I haven't tried it on white clays. The following
> > results are based on brown clays:
> >
> > 5% Zircopax makes a semi-opaque glaze that allows some of the body
> > color to show through. 10% Zircopax makes white.
> >
> > 3% tin makes a nice white, not completely opaque
> >
> > 3% tin plus 0.5-2% cobalt carbonate makes soft blues (I thought I'd
> > get purples with all that magnesia -- anyone know why not?)
> >
> > 3% tin plus 4-8% rutile makes soft yellows (oddly, to me, the yellows
> > were much paler on the darker clays, much nicer -- more gold -- on
> > the Miller 50)
> >
> > And my favorite:
> >
> > 3% tin plus 2% Red Iron Oxide makes a light tan that breaks
> > beautifully to rust brown on edges, throwing ridges, etc. Again a
> > fairly thin coat of glaze works best. Thicker application
> > makes more of a cream-tan.
> >
> > 3% tin plus 4% RIO gives a lovely bright rust.
> >
> > More iron makes a deep brown with reddish undertones (does not get
> > redder with refiring).
> >
> > This glaze apparently is teetering on the brink of being satin-matte
> > or semi-gloss. Additions of tin and colorants definitely pushed it
> > in the direction of gloss, with some of the variations being quite
> > glossy.
> >
> > Happy testing!
> >
> > Chris
> > Light One Candle Pottery
> > Fuquay-Varina, NC
> > candle@intrex.net
> >
> >
>
>
Light One Candle Pottery
Fuquay-Varina, NC
candle@intrex.net

Ron Roy on sun 21 nov 99

Hi Chris,

When giving analysis for materials it is important to give any loss on
ignition - for instance the analysis for whiting has about 45% LOI and EPK
has has about 13% - the higher the number the more effect it will have on
calculations.

If your glaze program has no way of dealing with LOI throw it out or send
it back.

Here are typical analysis:

Talc - from Vanderbuilt March 15/91 Nytal 100
SiO2 - 55.20
MgO - 30.0
CaO - 8.42
Fe2O3 - 0.16
Al2O3 - 0.31
MnO2 - 0.17
Na2O - 0.34
LOI - 5.41
Total 100.1

G200 spar (Yours will work OK - the LOI for spar are qiute low - in this
case 0.16)
SiO2................ 66.86
AL2O3............... 18.41
Fe2O3............... .08
CaO................. .81
K2O................. 10.67
Na2O................ 3.01
L.O.I. ............. .16
----------
100.00

EPK Downloaded from Feld Corp Sept 97

SiO2 - 45.73
Al2O3 - 37.36
Fe2O3 - 0.79
TiO2 - 0.37
P2O5 - 0.236
CaO - 0.18
MgO - 0.098
Na2O - 0.059
K2O - 0.33
LOI 13.91
Total - 99.063

Ferro Frit 3124 Yours is fine in this case Chris

CaO - 14.09%
K2O - 0.71%
Na2O - 6.30%
Al2O3 - 9.89%
B2O3 - 13.70%
SiO2 - 55.30%

There is no LOI for frits - they have already been melted so anything that
was liberated is simply not there anymore.

RR

>G-200 is a potash feldspar, analysis from Insight is:
>
> CaO 0.01 0.82%
> MgO 0.00 0.05%
> K2O 0.11 10.80%
> Na2O 0.05 3.05%
> Al2O3 0.18 18.58%
> SiO2 1.11 66.61%
> Fe2O3 0.00 0.09%
>
>Ferro Frit 3124 is:
>
> CaO 0.25 14.09%
> K2O 0.01 0.71%
> Na2O 0.10 6.30%
> Al2O3 0.10 9.89%
> B2O3 0.20 13.70%
> SiO2 0.92 55.30%
>
>EPK is Edgar Plastic Kaolin, a china clay:
>
> CaO 0.00 0.22%
> MgO 0.00 0.12%
> K2O 0.00 0.41%
> Na2O 0.00 0.08%
> TiO2 0.00 0.45%
> Al2O3 0.37 43.86%
> P2O5 0.00 0.31%
> SiO2 0.77 53.67%
> Fe2O3 0.00 0.89%
>
>I assume you have talc, dolomite, and silica (flint) -- I use 325
>mesh).
>
>Hope this gives you what you need. Good luck.
>
>Chris

Ron Roy
93 Pegasus Trail
Scarborough
Ontario, Canada
M1G 3N8
Evenings 416-439-2621
Fax 416-438-7849