Caryl W. on sat 21 nov 98
Hi,
I need to pick the brains of some of the" glaze gurus" out there...I
have two very nice glazes that I use, which are quite successful on
their own, but when put one over the other or vice-versa, do something
quite extraordinary.
The first is what I call Butterscotch ^6-oxydation:
neph.sy.1150
whiting 975
epk 975
silica 1500
gerstley bor.550
superpax 250
rutile 300
manganese dioxide .50
This gives a nice,glossy butterscotch colour on a white clay that works
with pink stains without burning them out.
The other I call Seafoam Blue ^6 oxydation:
custer feldspar 1775
whiting 900
zinc oxide 300
epk 1000
silica 1100
tin oxide 150
cobalt carb 37.5
chrome oxide 37.5
rutile 150
This gives a semi- matt,satin grey/green with blue specks.
Together, on white clay with the seafoam first,then the butterscotch, I
get an amazing grey/green with purply burgundy breaking through,with
between a satin and a gloss finish.In reverse, I get more of a golden
green with a deeper burgundy red breaking through with a true gloss
surface.
I know the one glaze contains tin/chrome and this could account for it,
but why only in combo with the other glaze and not when its on its own?
I'm certainly not complaining about the results, but would like a better
understanding.I know ignorance is bliss, but I keep asking why!!
Thanks in advance
Caryl
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com
Ron Roy on tue 24 nov 98
Hi Caryl,
Some comments about these glazes first - they both apprear durable when
checked against the limits I use - which means enough alumina and silica to
be stable according to my experience anyway. They are similar in expansion
and not unsimilar in the amounts of alumina and silica in each.
The differences: butterscotch is over supplied with CaO, is more glossy
because it has the boron and a higher ratio, and the yellow colour is from
the rutil.
The blue: A better balanced glaze in that there is only a slight over
supply of CaO and more Alumina and silica. What is most unusual - when you
want chrome/tin pinks you don't want zinc in the glaze - which prevents the
reds .
So you are mixing a glaze (butterscotch) which is good for chrome/tin pinks
(no ZnO and high CaO) - but has no chrome or tin - with a glaze (seafoam
blue) that has chrome and tin and ZnO.
Talk about using glaze technology to develope interesting glaze effects
with durable glazes - guess you can do it without even knowing how to but -
imagine how much more creative you could be if you did know.
Thanks for telling us all about this - it is a wonderful example of the
possibility of solving both problems.
>----------------------------Original message----------------------------
>Hi,
>
>I need to pick the brains of some of the" glaze gurus" out there...I
>have two very nice glazes that I use, which are quite successful on
>their own, but when put one over the other or vice-versa, do something
>quite extraordinary.
>
>The first is what I call Butterscotch ^6-oxydation:
>
>neph.sy.1150
>whiting 975
>epk 975
>silica 1500
>gerstley bor.550
>superpax 250
>rutile 300
>manganese dioxide .50
>
>This gives a nice,glossy butterscotch colour on a white clay that works
>with pink stains without burning them out.
>
>The other I call Seafoam Blue ^6 oxydation:
>
>custer feldspar 1775
>whiting 900
>zinc oxide 300
>epk 1000
>silica 1100
>tin oxide 150
>cobalt carb 37.5
>chrome oxide 37.5
>rutile 150
>
>This gives a semi- matt,satin grey/green with blue specks.
>
>Together, on white clay with the seafoam first,then the butterscotch, I
>get an amazing grey/green with purply burgundy breaking through,with
>between a satin and a gloss finish.In reverse, I get more of a golden
>green with a deeper burgundy red breaking through with a true gloss
>surface.
>
>I know the one glaze contains tin/chrome and this could account for it,
>but why only in combo with the other glaze and not when its on its own?
>
>I'm certainly not complaining about the results, but would like a better
>understanding.I know ignorance is bliss, but I keep asking why!!
>Thanks in advance
>Caryl
Ron Roy
93 Pegasus Trail
Scarborough, Ontario
Canada M1G 3N8
Tel: 416-439-2621
Fax: 416-438-7849
Web page: http://digitalfire.com/education/people/ronroy.htm
May Luk on thu 15 jul 10
Hello Bob;
Try Out of the Earth, Into the Fire by Mimi Obstler. Deconstruct a
recipe and look at the materials and its proportion in the glaze, you
can kind of tell what the materials would do in what conditions.
(oxidation, reduction, fast fire, slow cool) Top that with firing the
wares in both vertical and horizontal positions and please consider
thickness of applications and clay color as well.
May
Brooklyn
On Thu, Jul 15, 2010 at 1:47 PM, Bob Johnson wrote:
> After taking a Steven Hill workshop, I have become interested in discover=
ing
> how layers of glaze interact with each other. (For example, Steven sprays
> various glazes over his Strontium Crystal Magic to make small, interestin=
g
> titanium crystals.)
>
>
>
> My question is this: Are there ways to predict what kind of effect one mi=
ght
> get from layering glazes? That is, can we look at two glaze recipes and
> predict how they will interact-or is it all trial-and-error? I'm interest=
ed
> not so much in how colors combine but in the resulting textures and patte=
rns
> that different combinations of glazes produce. Perhaps some of you glaze
> chemists can suggest a book that discusses this-or, even better, some sim=
ple
> rules of thumb.
>
>
>
> Bob
>
> in Roseburg, Oregon
>
--
http://twitter.com/MayLuk
Bob Johnson on thu 15 jul 10
After taking a Steven Hill workshop, I have become interested in discoverin=
g
how layers of glaze interact with each other. (For example, Steven sprays
various glazes over his Strontium Crystal Magic to make small, interesting
titanium crystals.)
My question is this: Are there ways to predict what kind of effect one migh=
t
get from layering glazes? That is, can we look at two glaze recipes and
predict how they will interact-or is it all trial-and-error? I'm interested
not so much in how colors combine but in the resulting textures and pattern=
s
that different combinations of glazes produce. Perhaps some of you glaze
chemists can suggest a book that discusses this-or, even better, some simpl=
e
rules of thumb.
Bob
in Roseburg, Oregon
Randy McCall on thu 15 jul 10
I would also like to see more discussion on glaze interactions. For the pa=
=3D
st few years I have been moving towards layering and combining glazes to ge=
=3D
t more texture and depth. Most single glazes are rather boring and bland e=
=3D
specially at cone 6. Thanks to Jane Shatz=3D2C Richard Brusch=3D2C Ron Roy=
=3D2C =3D
and John Hesselberth I have been able to develop a better palate of glazes =
=3D
that have improved my work. Layering of some of the commericial glazes lik=
=3D
e Coyotte has also helped.
=3D20
Love to see those pieces with a WOW glaze/glazes. Looking for more........=
=3D
..........
Randy
=3D
Ron Roy on fri 16 jul 10
Hi Bob,
Glazes go through bubbling and foaming stages sometimes - if the glaze
underneath does that after the glaze on top you would get a certain
kind of texture.
Glaze calculation software should be a real help in developing
different systems and predicting certain textures.
If you want to go further with that I can explain it in more detail.
RR
Quoting Bob Johnson :
> After taking a Steven Hill workshop, I have become interested in discover=
ing
> how layers of glaze interact with each other. (For example, Steven sprays
> various glazes over his Strontium Crystal Magic to make small, interestin=
g
> titanium crystals.)
>
>
>
> My question is this: Are there ways to predict what kind of effect one mi=
ght
> get from layering glazes? That is, can we look at two glaze recipes and
> predict how they will interact-or is it all trial-and-error? I'm interest=
ed
> not so much in how colors combine but in the resulting textures and patte=
rns
> that different combinations of glazes produce. Perhaps some of you glaze
> chemists can suggest a book that discusses this-or, even better, some sim=
ple
> rules of thumb.
>
>
>
> Bob
>
> in Roseburg, Oregon
>
Eric Hansen on fri 16 jul 10
check out Fong Choo - that is what he's been doing
On Thu, Jul 15, 2010 at 10:07 PM, Randy McCall wrote:
> I would also like to see more discussion on glaze interactions. For the
> past few years I have been moving towards layering and combining glazes t=
o
> get more texture and depth. Most single glazes are rather boring and bla=
nd
> especially at cone 6. Thanks to Jane Shatz, Richard Brusch, Ron Roy, and
> John Hesselberth I have been able to develop a better palate of glazes th=
at
> have improved my work. Layering of some of the commericial glazes like
> Coyotte has also helped.
>
>
>
> Love to see those pieces with a WOW glaze/glazes. Looking for
> more..................
>
> Randy
>
>
>
--
Eric Alan Hansen
Stonehouse Studio Pottery
Alexandria, Virginia
americanpotter.blogspot.com
thesuddenschool.blogspot.com
hansencookbook.blogspot.com
"To me, human life in all its forms, individual and aggregate, is a
perpetual wonder: the flora of the earth and sea is full of beauty and of
mystery which seeks science to understand; the fauna of land and ocean is
not less wonderful; the world which holds them both, and the great universe
that folds it in on everyside, are still more wonderful, complex, and
attractive to the contemplating mind." - Theodore Parker, minister,
transcendentalist, abolitionist (1810-1860)
David Beumee on sun 18 jul 10
Bob,
Until you begin to layer glazes according to the way the glazes are dry
mixed, allowed to settle, wet mixed, screened, adjusted for flocculation,
possibly ball milled, applied according to your particular method, accordin=
g
to the bisque temperature and thickness of your particular pots, according
to the particular fired color of the clay body you are using, whether or no=
r
you use slip or terra sig underneath your applied layers of glaze, accordin=
g
to the shape and texture of the pots, and fired under your particular
conditions to the temperature you fire, you will never know how layered
glazes will work for you. If you want to know more, I'd be happy to give
some guidelines for testing procedures. I've worked with layering glazes on
porcelain at cone 10 in reduction for decades.
David Beumee
Porcelain by David Beumee
Lafayette, CO
On Thu, Jul 15, 2010 at 11:47 AM, Bob Johnson wrote:
> After taking a Steven Hill workshop, I have become interested in
> discovering
> how layers of glaze interact with each other. (For example, Steven sprays
> various glazes over his Strontium Crystal Magic to make small, interestin=
g
> titanium crystals.)
>
>
>
> My question is this: Are there ways to predict what kind of effect one
> might
> get from layering glazes? That is, can we look at two glaze recipes and
> predict how they will interact-or is it all trial-and-error? I'm interest=
ed
> not so much in how colors combine but in the resulting textures and
> patterns
> that different combinations of glazes produce. Perhaps some of you glaze
> chemists can suggest a book that discusses this-or, even better, some
> simple
> rules of thumb.
>
>
>
> Bob
>
> in Roseburg, Oregon
>
David Finkelnburg on mon 19 jul 10
I have to say David Beumee achieves some beautiful effects with his use of
glaze layering. I have a vessel sitting here that David made and I just
marvel at it's appearance, totally different than the sort of layering
effect I strive for, very contrasty and striking. David's diligent testing
is apparent in his fine work!
Dave Finkelnburg
http://www.mattanddavesclays.com
-----------------------------
Date: Sun, 18 Jul 2010 08:20:15 -0600
From: David Beumee
Subject: Re: glaze interactions
Bob,
Until you begin to layer glazes according to the way the glazes are dry
mixed, allowed to settle, wet mixed, screened, adjusted for flocculation,
possibly ball milled, applied according to your particular method, accordin=
g
to the bisque temperature and thickness of your particular pots, according
to the particular fired color of the clay body you are using, whether or no=
r
you use slip or terra sig underneath your applied layers of glaze, accordin=
g
to the shape and texture of the pots, and fired under your particular
conditions to the temperature you fire, you will never know how layered
glazes will work for you. If you want to know more, I'd be happy to give
some guidelines for testing procedures. I've worked with layering glazes on
porcelain at cone 10 in reduction for decades
Bob Johnson on mon 19 jul 10
David: I'd love to get some glaze testing guidelines--and I'm sure others o=
n
the list would, too.
Thanks!
Bob
Roseburg, OR
-----Original Message-----
From: David Beumee [mailto:dtbeumee@WILDBLUE.NET]
Sent: Sunday, July 18, 2010 7:20 AM
Subject: Re: glaze interactions
Bob,
Until you begin to layer glazes according to the way the glazes are dry
mixed, allowed to settle, wet mixed, screened, adjusted for flocculation,
possibly ball milled, applied according to your particular method, accordin=
g
to the bisque temperature and thickness of your particular pots, according
to the particular fired color of the clay body you are using, whether or no=
r
you use slip or terra sig underneath your applied layers of glaze, accordin=
g
to the shape and texture of the pots, and fired under your particular
conditions to the temperature you fire, you will never know how layered
glazes will work for you. If you want to know more, I'd be happy to give
some guidelines for testing procedures. I've worked with layering glazes on
porcelain at cone 10 in reduction for decades.
David Beumee
Porcelain by David Beumee
Lafayette, CO
Ron Roy on mon 19 jul 10
Hi Bob,
Do you have a glaze calculator?
Keep notes - you can then look at the molecular formula generated by a
calculation program you can make comparisons.
One experiment could be - if you have a glaze with a lot of alumina in
it and it works well under a glaze with less alumina you can them
alter each or both glazes adding and subtracting alumina to get more
dramatic results.
Surface tension is also a factor - you can find out which oxides raise
or lower surface tension (see the Hamer book) and adjust glazes both
ways.
Keep track of the things you see happening that you like - if you
don't want to get into calculation then send me the results you want
to amplify and I'll do it for you.
RR
Quoting Bob Johnson :
> Yes, I would be very interested in more information on glaze interactions=
!
>
> Sometimes I see one glaze beading or crawling when used over another.
> Sometimes the underglaze will promote small crystals, as is the case with
> Strontium Crystal Magic. Sometimes there is a sort of oil-and-water
> effect...
>
> It seems likely that differential maturation temperatures would be a big
> factor--producing the foaming that you mentioned. Are there other
> predictable factors, such as alkalinity or metal content or surface tensi=
on
> at temperature or...? Basically, I'm looking for a way to experiment
> smarter. You mentioned using glaze software...
>
> Thanks!
>
> Bob
> --in Roseburg, Oregon
>
> -----Original Message-----
> From: Ron Roy [mailto:ronroy@CA.INTER.NET]
> Sent: Friday, July 16, 2010 8:17 AM
> Subject: Re: glaze interactions
>
> Hi Bob,
>
> Glazes go through bubbling and foaming stages sometimes - if the glaze
> underneath does that after the glaze on top you would get a certain
> kind of texture.
>
> Glaze calculation software should be a real help in developing
> different systems and predicting certain textures.
>
> If you want to go further with that I can explain it in more detail.
>
> RR
>
>
>
Bob Johnson on mon 19 jul 10
Yes, I would be very interested in more information on glaze interactions!
Sometimes I see one glaze beading or crawling when used over another.
Sometimes the underglaze will promote small crystals, as is the case with
Strontium Crystal Magic. Sometimes there is a sort of oil-and-water
effect...
It seems likely that differential maturation temperatures would be a big
factor--producing the foaming that you mentioned. Are there other
predictable factors, such as alkalinity or metal content or surface tension
at temperature or...? Basically, I'm looking for a way to experiment
smarter. You mentioned using glaze software...
Thanks!
Bob
--in Roseburg, Oregon
-----Original Message-----
From: Ron Roy [mailto:ronroy@CA.INTER.NET]
Sent: Friday, July 16, 2010 8:17 AM
Subject: Re: glaze interactions
Hi Bob,
Glazes go through bubbling and foaming stages sometimes - if the glaze
underneath does that after the glaze on top you would get a certain
kind of texture.
Glaze calculation software should be a real help in developing
different systems and predicting certain textures.
If you want to go further with that I can explain it in more detail.
RR
David Beumee on mon 19 jul 10
Hi Bob and everybody,
Overlapping glazes produces an entirely different effect than mixing
glazes together. Start with bars of the clay body you use. The test bars I
make are approx. 6"L x 1.75"W x 3/8" H. I have a cutoff device shaped like
an upside down U, with a wire stretched across the bottom and an adjustable
roller above the wire, that I adjust to make 3/8" thick slabs, which I then
cut to size. If you use a 25 pd. block of clay from a manufacturer, you can
make a great many test bars very quickly in this way. The test bars need to
be dried slowly to avoid warping, and my bisque temperature is cone 09.
Let's say you have two glazes that you'd like to see overlapped. My
numbering system is letters and numbers, so for instance glaze A might be
numbered H-41 and glaze B might be numbered M-29. Use a small brush and an
iron or black stain to mark the side of your test bar, considering that one
half of the bar is glaze A and half the bar is glaze B. Wax out the bottom
and sides and ends of the test bar, being careful not to get any wax on the
top of the bar. You can use as little as two cup containers of glaze A and
glaze B, making sure that both glazes are well mixed and of the viscosity
that has proven useful. Dip one half of the test bar in glaze A and the
other half in glaze B. Remember that thicker applications of glaze gives
more information than thin applications. Set aside to dry. I allow 8 to 12
hours in the dry Colorado climate. Now use a brush and mark a line of wax
down the center of the top of the bar, about a quarter inch wide, and allow
to dry. Now it's time to do the overlap. Be sure that both glaze A and B ar=
e
well mixed. Dip the A side of the test bar in glaze B, and the B side of th=
e
test bar in glaze A, remembering that the overlapping glazes do not need as
long a dip (usually) as the first dips to work, and that very often second
dips will peel if applied too thickly. The wax will make a resist, which yo=
u
may find very striking and useful.
Fire to the temperature and atmosphere that you've established that works
for you. The drawback of this way of testing is that these are horizontal
tests, so you don't get to see if the layered glazes run, something that ca=
n
happen easily when two layers of glaze are on top of each other. What you d=
o
get to see is how two glazes react with one another, A over B and B over A,
and you get to see how wax resist works with the two glazes. The
possibilities are endless.
David Beumee
Porcelain by David Beumee
Lafayette, CO
www.davidbeumee.com
On Mon, Jul 19, 2010 at 11:02 AM, Bob Johnson wrote:
> David: I'd love to get some glaze testing guidelines--and I'm sure others
> on
> the list would, too.
> Thanks!
> Bob
> Roseburg, OR
>
> -----Original Message-----
> From: David Beumee [mailto:dtbeumee@WILDBLUE.NET]
> Sent: Sunday, July 18, 2010 7:20 AM
> Subject: Re: glaze interactions
>
> Bob,
> Until you begin to layer glazes according to the way the glazes are dry
> mixed, allowed to settle, wet mixed, screened, adjusted for flocculation,
> possibly ball milled, applied according to your particular method,
> according
> to the bisque temperature and thickness of your particular pots, accordin=
g
> to the particular fired color of the clay body you are using, whether or
> nor
> you use slip or terra sig underneath your applied layers of glaze,
> according
> to the shape and texture of the pots, and fired under your particular
> conditions to the temperature you fire, you will never know how layered
> glazes will work for you. If you want to know more, I'd be happy to give
> some guidelines for testing procedures. I've worked with layering glazes =
on
> porcelain at cone 10 in reduction for decades.
>
> David Beumee
> Porcelain by David Beumee
> Lafayette, CO
>
>
>
Lee Love on mon 19 jul 10
I do a lot of layering of glazes. The best way to figure them out is
by doing many tests and keeping good records.
--
Lee, a Mashiko potter in Minneapolis
http://mingeisota.blogspot.com/
=3D93Observe the wonders as they occur around you. Don't claim them. Feel
the artistry moving through and be silent.=3D94 --Rumi
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