Ken Chin-Purcell on fri 7 apr 00
I learned how to make pots in "Mingeisotta", hence in the past I've
fired the bulk of my work at cone 10 reduction. For the next 2-3
years however I will be using an electric kiln, and I'm about to
launch into developing new glazes for my functional stoneware.
To my eye and hand, cone 9 glazes seem more appealing that cone 6;
they seem softer and have more character. And so I wonder, is
this a property of cone 9 fluxes that just can't be duplicated?
Or is it usually possible, using glaze calculation and experiments,
to tweak the recipe and obtain similar results at cone 6?
And just how hard on the elements is cone 9?
-- Ken
In sunny Ireland (at least today...)
Pat Taylor on sat 8 apr 00
Ken,
A few years back I was in your situation of having to make a transition
from gas fired kilns to electric kilns and glazes. I used cone 6 glazes
because of the firing range limitations of the electric kilns. Most of the
electric kilns were rated between cone 6 to 8. Since I was constantly doing
glaze firings , I thought that not pushing the kilns to their "outer firing
limits" would prolong the life of the elements and other critical
components.
In addition, I found that some of the electric kilns rated for cone 8 had
a hard time of consistently reaching that temperature, especially after a
few years of operation. I haven't glazed fired in electric kilns for
several years. There may be newer models that other folks know about that
are capable of reaching cone 9 without any effort. I used medium to large
electric kilns designed for studio use.
I am now in a situation where I bisque and glaze fire in a gas kiln.
Give my regards to the folks in sunny Ireland.
Patrick "Flanagan" Taylor
Charles G Hughes on sat 8 apr 00
I too switched from cone 9-11 to cone 6 electric oxidation, I HATED it for
the longest time, now after 5 years of research, I have found some glazing
techniques that make me happy. These pots have a hard liner glaze for the
food surface, a satin matte yellow or blue glaze on the outside, which is
then fluxed by copper oxide and woodash.
Check them out and see if they look cone 6 to you. Most of the potters I
meet are suprised that they are cone 6.
http://www.thecreativeoasis.com/Hughes/hughesnewwork.html
Also...
After using ITC products, I am convinced that an electric kiln coated with
ITC can fire to cone 9 repeatedly with far less damage than used to occur.
It is wonderful stuff. Of course at cone 9 oxidation pots still leave me
with an empty feeling. I think it is the reduction I/we miss. Of course if
Mel and Nils electric reduction kiln works out, we are going to have some
new options to experiment with. Can't wait for the results on that one!
-Charles
----- Original Message -----
From: Ken Chin-Purcell
To:
Sent: Friday, April 07, 2000 1:00 PM
Subject: Cone 6 vs. Cone 9 ox
> ----------------------------Original message----------------------------
> I learned how to make pots in "Mingeisotta", hence in the past I've
> fired the bulk of my work at cone 10 reduction. For the next 2-3
> years however I will be using an electric kiln, and I'm about to
> launch into developing new glazes for my functional stoneware.
>
> To my eye and hand, cone 9 glazes seem more appealing that cone 6;
> they seem softer and have more character. And so I wonder, is
> this a property of cone 9 fluxes that just can't be duplicated?
> Or is it usually possible, using glaze calculation and experiments,
> to tweak the recipe and obtain similar results at cone 6?
>
> And just how hard on the elements is cone 9?
>
> -- Ken
> In sunny Ireland (at least today...)
Bob Hamm on sat 8 apr 00
To my eye and hand, cone 9 glazes seem more appealing that cone 6;
they seem softer and have more character. And so I wonder, is
this a property of cone 9 fluxes that just can't be duplicated?
Or is it usually possible, using glaze calculation and experiments,
to tweak the recipe and obtain similar results at cone 6?
Ken
I have been a production potter firing all my work in electric kilns for 25
years. For 20 years I fired to cone 8 and cone 9. In 1995 I moved down to
cone 6 glazes. I have had experinced potters who were surprised to learn my
cone 8 work was not reduced. By choice I did not try to make my cone 6 work
look reduced. When you compare cone 6 glazes to cone 9 glazes, make sure
they are both fired in oxidation. Most highfire pots I have seen are
reduced.
As to your question, yes you can make glazes for electric oxidation that are
soft and have character. To do this consider the clay body you use and how
it reacts with your glazes, and play around with the firing schedule. I
found that slow firings( up and down) with a soak between 900' C to 1050' C
can warm up a glaze. There are a variety of other manipulations I have used
that I would be happy to share.
And just how hard on the elements is cone 9?
I have just ordered new elements for the first time in two years. In the
past I ordered elements at least once a year. In my opion that is a majour
saving. Do not forget furniture. It warps and degrades much faster at cone
9. And those last 3 cone will add sustantial time( another cost) to the
firing. Temperature increases slow down at the top, particularly as your
elements get older.
Feel free to contact me if you would like more information on glazes and
firing processes.
Bob
Listening with interest to the electric gas kiln thread. My homebuilts are
22 and 25 years old and looking very sad.
Bob Hamm
Super Mud Works
Kelowna, BC Canada
Ph (250) 765-8876
Email hamm@direct.ca
Debby Grant on sat 8 apr 00
Dear Ken,
In my 30 odd years as a potter I have run the gamut - started with
earthenware, then ^5-6, and finally ended up with ^9-10 both in
reduction and oxidation. While I was teaching I had the use of a
gas kiln at the school as well as my homemade electric at home.
Many of the glazes I used were fine in both atmospheres, albeit
somewhat different and infinitely more pleasing than the ^5-6 glazes.
In fact the reason I switched to ^10 was that the glazes appear to
me so much more a part of the clay melt rather than like a glove so
speak, pulled over the pot. Yes, I really do think there is a difference.
And it really doesn't take very much more energy to go from ^6 to
^9-10. Though I am now retired I still can use the gas kiln at school
but, I don't bother because I'm perfectly satisfied with the effects I
get in my electric.
I'm sure you will get the opposite advice from many people but I just
had to give you my 2 cents worth.
Good luck in whatever decision you make.
Debby Grant in New Hampshire
Ray Aldridge on sat 8 apr 00
At 01:00 PM 4/7/00 EDT, you wrote:
>To my eye and hand, cone 9 glazes seem more appealing that cone 6;
>they seem softer and have more character. And so I wonder, is
>this a property of cone 9 fluxes that just can't be duplicated?
>Or is it usually possible, using glaze calculation and experiments,
>to tweak the recipe and obtain similar results at cone 6?
Much of the effect you're talking about, in my opinion, comes from two
factors other than the heat-work. One is that reduction tends to make
glazes more active and less garish, and the other is that fuel-burning
kilns tend to be bigger and better insulated than electric kilns, so that
they cool more slowly. This slow cooling has a substantial effect on the
character of glazes, because it allows a much greater degree of
recrystallization.
But still, I'm of the opinion that it's easier to get good-looking glazes
at higher temps. The higher you fire, the more interaction there is
between body and glaze, and this is a big factor. The generally
characterless quality of most earthenware glazes, in which the glaze
appears to be no more than a surface coating of glass, and not a part of
the ware, is due to the lack of interaction. Another big factor is that at
the lower temperature, potters are forced to use a fair amount of boron to
get active glazes, and to my eye and fingers, high boron glazes are less
beautiful than those fluxed with the traditional hightemp fluxes. And they
seem in general to be less durable.
You might consider a compromise. I fire at C8, because in this range, the
traditional highfire fluxes are reasonably active and I can use much less
boron. There seems to be a surprisingly big difference between what's
practical at C6 and what's practical at C8. In fact, I'm currently working
on a series of tests based on Nigel Wood's excellent book _Oriental
Glazes_, particularly the Sung celadons, which were fired in this range,
using glazes of very simple analysis... and without boron. In the last few
months, I've taken to using clear liner glazes on most of my domestic
porcelain. I'm hoping to develop a glaze for this purpose with a little of
the rich and subtle character of these wonderful glazes-- test tiles are in
a bisque kiln as I type. Similar glazes were sometimes used in oxidation
in China, and I think that with the proper cooling they'll look good even
without the reduced iron of the celadons.
>
>And just how hard on the elements is cone 9?
>
It's a lot harder than C6. But handmakers have to compete on qualities
other than strictly economic considerations. Consider that a kiln-load of
pots will probably pay for a new set of elements, and you'll still get many
firings from a typical set of elements, even at the higher temps. The
extra cost of going to the higher temps will amount to pennies per pot, so
I don't see this as a major consideration.
I have no personal knowledge of this, but several wise folk on the list say
that ITC refractory coatings can indefinitely extend the life of elements,
even in hybrid (electric reduction) kilns.
Ray
Aldridge Porcelain and Stoneware
http://www.goodpots.com
Wade Blocker on sat 8 apr 00
----------
> From: Ken Chin-Purcell
> To: CLAYART@LSV.UKY.EDU
> Subject: Cone 6 vs. Cone 9 ox
> Date: Friday, April 07, 2000 11:00 AM
>
> ----------------------------Original message----------------------------
> I learned how to make pots in "Mingeisotta", hence in the past I've
> fired the bulk of my work at cone 10 reduction. For the next 2-3
> years however I will be using an electric kiln, and I'm about to
> launch into developing new glazes for my functional stoneware.
>
> To my eye and hand, cone 9 glazes seem more appealing that cone 6;
> they seem softer and have more character. And so I wonder, is
> this a property of cone 9 fluxes that just can't be duplicated?
> Or is it usually possible, using glaze calculation and experiments,
> to tweak the recipe and obtain similar results at cone 6?
>
> And just how hard on the elements is cone 9?
>
> -- Ken
> In sunny Ireland (at least today...)
Ken,
I used to fire to cone 9 to 10 with my electric kiln. I had the kiln
elements replaced every l8months to 2 years. I have been firing at cone 5
to 6 for the past years and now the elements last for over 4 years.With a
bit of testing you can find cone 6 glazes that do everything that firing to
a higher temperature did. Mia in sunny and warm ABQ
Cheryl L Litman on mon 10 apr 00
Does anyone yet have enough personal experience to comment on whether a
coating of the ITC 213 product on the elements will extend their life
significantly? Maybe that's a solution to the cone 6 vs 8/9 problem in
the electric kilns?
Cheryl Litman ---------- Somerset, NJ --------- email:
cheryllitman@juno.com
***Experience is what allows you to recognize a mistake......when you
make it again.***
> Ken,
> I used to fire to cone 9 to 10 with my electric kiln. I had the
> kiln
> elements replaced every l8months to 2 years. I have been firing at
> cone 5
> to 6 for the past years and now the elements last for over 4
> years.With a
> bit of testing you can find cone 6 glazes that do everything that
> firing to
> a higher temperature did. Mia in sunny and warm ABQ
Cheryl Litman ---------- Somerset, NJ --------- email:
cheryllitman@juno.com
***Experience is what allows you to recognize a mistake......when you
make it again.***
Debby Grant on tue 11 apr 00
Dear Cheryl,
If you'll remember, I am the proponent of ^10 firing in an electric kiln, and
yes, I sprayed the inside of my kiln with ITC about 2 years ago and have
not had to change an element since. I should also mention that my husband,
who is an electrical engineer, built my kiln and we wind our own elements.
I used to have to replace them more often so I think ITC does help.
By the way, are you planning to attend the next North Country Conference?
Debby Grant in NH
Ron Roy on thu 13 apr 00
Hi Ken,
It is easier to make glazes with "body" at cone 9 because the feldspars are
melting well at that temperature. You can also get more silica and alumina
in higher fired glazes - this helps make better glass as well.
Colour seems to drop off above cone 6 - at least with the brighter colours
- or should I say harder to keep bright.
I taught for years at cone 8 - which I thought was a good compromise for
electric firing. Glazes can be more stable and clay has a better range than
at 6.
The key here is how much flux you have to add - at any temperature - to get
clays and glazes to melt. The less flux the better the range - simply
because the melting can proceed slower with less flux.
RR
>----------------------------Original message----------------------------
>I learned how to make pots in "Mingeisotta", hence in the past I've
>fired the bulk of my work at cone 10 reduction. For the next 2-3
>years however I will be using an electric kiln, and I'm about to
>launch into developing new glazes for my functional stoneware.
>
>To my eye and hand, cone 9 glazes seem more appealing that cone 6;
>they seem softer and have more character. And so I wonder, is
>this a property of cone 9 fluxes that just can't be duplicated?
>Or is it usually possible, using glaze calculation and experiments,
>to tweak the recipe and obtain similar results at cone 6?
>
>And just how hard on the elements is cone 9?
>
>-- Ken
>In sunny Ireland (at least today...)
Ron Roy
93 Pegasus Trail
Scarborough
Ontario, Canada
M1G 3N8
Evenings 416-439-2621
Fax 416-438-7849
Tasha Olive on thu 13 apr 00
Been following this thread with mild interest....finally decided to put my
two cents in. I fire to cones 6, 7 and rarely cone 8 in oxidation in my
electric kiln but also I fire to cone 8-9 reduction in my gas kilns. I know,
I know, too much diversity I can hear some saying. May be right, but I do
this because I have found that many of the high-fired glazes seem to be
"potter's glazes,meaning that we are crazy about them but they don't
necessarily sell to the public as well as some of the "brighter" lower-fired
oxidation glazes. Now, before some of you come unglued, I am NOT saying this
is always true...just have found it to be something that definitely seems to
go on. Soooo.... I do things in one kiln to make some profits and fire in my
gas kilns for myself and for "arty" pieces, and yes, they too, sell quite
often and when they do, I find I can ask and get quite a bit more for them.
But, that line of thought would take us into the weird economics thread.
Tasha
-----Original Message-----
From: Ray Aldridge
To: CLAYART@LSV.UKY.EDU
Date: Saturday, April 08, 2000 8:48 PM
Subject: Re: Cone 6 vs. Cone 9 ox
----------------------------Original message----------------------------
At 01:00 PM 4/7/00 EDT, you wrote:
>To my eye and hand, cone 9 glazes seem more appealing that cone 6;
>they seem softer and have more character. And so I wonder, is
>this a property of cone 9 fluxes that just can't be duplicated?
>Or is it usually possible, using glaze calculation and experiments,
>to tweak the recipe and obtain similar results at cone 6?
Much of the effect you're talking about, in my opinion, comes from two
factors other than the heat-work. One is that reduction tends to make
glazes more active and less garish, and the other is that fuel-burning
kilns tend to be bigger and better insulated than electric kilns, so that
they cool more slowly. This slow cooling has a substantial effect on the
character of glazes, because it allows a much greater degree of
recrystallization.
But still, I'm of the opinion that it's easier to get good-looking glazes
at higher temps. The higher you fire, the more interaction there is
between body and glaze, and this is a big factor. The generally
characterless quality of most earthenware glazes, in which the glaze
appears to be no more than a surface coating of glass, and not a part of
the ware, is due to the lack of interaction. Another big factor is that at
the lower temperature, potters are forced to use a fair amount of boron to
get active glazes, and to my eye and fingers, high boron glazes are less
beautiful than those fluxed with the traditional hightemp fluxes. And they
seem in general to be less durable.
You might consider a compromise. I fire at C8, because in this range, the
traditional highfire fluxes are reasonably active and I can use much less
boron. There seems to be a surprisingly big difference between what's
practical at C6 and what's practical at C8. In fact, I'm currently working
on a series of tests based on Nigel Wood's excellent book _Oriental
Glazes_, particularly the Sung celadons, which were fired in this range,
using glazes of very simple analysis... and without boron. In the last few
months, I've taken to using clear liner glazes on most of my domestic
porcelain. I'm hoping to develop a glaze for this purpose with a little of
the rich and subtle character of these wonderful glazes-- test tiles are in
a bisque kiln as I type. Similar glazes were sometimes used in oxidation
in China, and I think that with the proper cooling they'll look good even
without the reduced iron of the celadons.
>
>And just how hard on the elements is cone 9?
>
It's a lot harder than C6. But handmakers have to compete on qualities
other than strictly economic considerations. Consider that a kiln-load of
pots will probably pay for a new set of elements, and you'll still get many
firings from a typical set of elements, even at the higher temps. The
extra cost of going to the higher temps will amount to pennies per pot, so
I don't see this as a major consideration.
I have no personal knowledge of this, but several wise folk on the list say
that ITC refractory coatings can indefinitely extend the life of elements,
even in hybrid (electric reduction) kilns.
Ray
Aldridge Porcelain and Stoneware
http://www.goodpots.com
Ken Chin-Purcell on fri 14 apr 00
Ron,
Thanks for replying. I was also thinking about cone 8, and
after trading some email with Ray Aldridge I think I'm sold.
My plan is to start with the flux ratios of some glazes that
I think are close to what I am after and perform some Ian
Currie style blends varying alumina and silica.
Now that I'm paying attention I've noticed many english
potters fire cone 8 ox. Not sure about my local Tipperary
potters yet - they're a more secretive bunch. :)
In your cone 8 teachings how much boron did you use? It seems
like a necessary flux at cone 6 but optional at cone 8.
I hope to take a workshop from you one of these days... are you
planning any trips to the UK?
-- Ken
----- Original Message -----
From: "Ron Roy"
To:
Sent: Thursday, April 13, 2000 1:24 PM
Subject: Re: Cone 6 vs. Cone 9 ox
> ----------------------------Original message----------------------------
> Hi Ken,
>
> It is easier to make glazes with "body" at cone 9 because the feldspars are
> melting well at that temperature. You can also get more silica and alumina
> in higher fired glazes - this helps make better glass as well.
>
> Colour seems to drop off above cone 6 - at least with the brighter colours
> - or should I say harder to keep bright.
>
> I taught for years at cone 8 - which I thought was a good compromise for
> electric firing. Glazes can be more stable and clay has a better range than
> at 6.
>
> The key here is how much flux you have to add - at any temperature - to get
> clays and glazes to melt. The less flux the better the range - simply
> because the melting can proceed slower with less flux.
>
> RR
>
> >----------------------------Original message----------------------------
> >I learned how to make pots in "Mingeisotta", hence in the past I've
> >fired the bulk of my work at cone 10 reduction. For the next 2-3
> >years however I will be using an electric kiln, and I'm about to
> >launch into developing new glazes for my functional stoneware.
> >
> >To my eye and hand, cone 9 glazes seem more appealing that cone 6;
> >they seem softer and have more character. And so I wonder, is
> >this a property of cone 9 fluxes that just can't be duplicated?
> >Or is it usually possible, using glaze calculation and experiments,
> >to tweak the recipe and obtain similar results at cone 6?
> >
> >And just how hard on the elements is cone 9?
> >
> >-- Ken
> >In sunny Ireland (at least today...)
>
> Ron Roy
> 93 Pegasus Trail
> Scarborough
> Ontario, Canada
> M1G 3N8
> Evenings 416-439-2621
> Fax 416-438-7849
>
Bob Hamm on sat 15 apr 00
Hi Ken,
I apologize for taking so long replying to your message. My modem died.
Computers can be so frustrating.
When I started making pots for a living in 1975, it seemed like every one
else was firing reduction in gas kilns to at least cone 9. I could not see
any reason why quality glazes could not be made in electric kilns so I chose
cone 8 electric oxidation. I stuck with it and after a lot of testing over
the next two years I was rewarded with a very good glaze. I have not done
anywhere near as much testing as I did for my first cone 8 glaze to develop
a number of strong cone 6 glazes. I do not think we know what can be done
at this temperature yet because not enough work has been done yet.
Ken I think your approach in selecting a group of differently fluxed glazes
is sound. I would suggest you keep the sampling small as it requires a lot
of testing to discover all the qualities a good base has to offer. I always
like to start with a clear glaze( no opacifiers or colorants) so I can
develop a good melt, a good fit, and the degree of fluidity I want.
I test my glazes on vertical surfaces with horizontal bands of cobalt, red
iron oxide, and a chrome tin stain to test fluidity, stain penetration, and
compatibility with chrome tin stains. The cobalt fluxes and the iron is
refractory.
When I have a good base then I try different opacifiers.
At this point my test kiln pays for itself. Now I fire these bases in
different schedules to test their ability to develop crystals. I would
try slow up( 50' C per hour last 150') fast down. Slow up and down. Then I
will add a short soak at the top(30 minutes). Long soaks cooling down 50'
over 4 hours. Starting at 1100', I050', and 1000'. Glazes react differently
to cooling rates and I want to see if they will crystallize and in what
range. When I know where they develop crystals I might try some very long
soaks (up to 10 hours) to see how far the glazes will crystallize before
they
go bad.
My preference is matte glazes that crystallize and gloss glazes that are
resistant. My matte glazes are gloss in a fast cooling kiln, but I can turn
their surface
a satin matte with a slow cooling cycle and make sandpaper with an
added 4 or 5 hour soak at the right temperature. I avoid the later. I
generally like a slow firing cycle to ensure a good glaze melt and time for
the glaze to interact with the clay body.
The other thing I like about slow up and down firing cycles is that the
glaze interaction with the clay body and the crystal development can warm
and soften a glaze and create interesting breaks on edges. Different glaze
and clay combinations react differently to soaks so they should be tested.
As for the appearance of depth. I like a soft satin matte with fine soft
speckles that look like they are held in a suspension of whole milk. I also
like glazes with crystalline blossoms floating on a clear and brighter
version
of themselves. I unloaded a pot this week that had soft mauve/tan crystals
over a clear gloss which was a dark blue gray fading up the pot into a moss
green then rusty tan before breaking on an edge with speckles of the white
body clay showing. This was one glaze (recipe later) over an iron stain
applied over a cobalt stain, all three sprayed. Variation in the stain
application and glaze thickness create this effect. I have found that thin
glazes resist crystallization so thick applications can result in this kind
of effect on clear backgrounds. This is all in a band 1 1/4 " high.
Boron compared to Calcium or Magnesium. There are always questions about
one flux compared to another but they all have their place and contribute
their own qualities. Fluxes are like people, the more we have the more
interesting life and pottery becomes.
This has become longer then I had intended so I will post the glazes later.
It will give me some time to recalculate them and remove the Gerstly Borate.
Bob; in Kelowna where it has been snowing all day.
Bob Hamm
Super Mud Works
Kelowna, BC Canada
Ph 250 765-8876
email hamm@direct.ca
Don & June MacDonald on sat 15 apr 00
I tried for some time to use a cone 8 firing temperature, however,
limited as I am to manufacturers clay bodies, I found it difficult to
achieve good results. Please don't suggest that I make my own clay, no
room, and I don't like the dust. I was able to achieve successful
glazes at this temperature, calcium works well as a flux, but I never
could find a clay body that was completely satisfactory at Cone 8, they
are either Cone 6 or Cone 10, and the Cone 6 bodies were over fired,
while the Cone 10 ones were underfired. I dropped to Cone 6 where there
are plenty of options, adjusted the glazes, and carried on.
The Cone 8 experiments were done in an electric kiln.
June
Ken Chin-Purcell wrote:
>
> ----------------------------Original message----------------------------
> Ron,
>
> Thanks for replying. I was also thinking about cone 8, and
> after trading some email with Ray Aldridge I think I'm sold.
> My plan is to start with the flux ratios of some glazes that
> I think are close to what I am after and perform some Ian
> Currie style blends varying alumina and silica.
>
> Now that I'm paying attention I've noticed many english
> potters fire cone 8 ox. Not sure about my local Tipperary
> potters yet - they're a more secretive bunch. :)
>
> In your cone 8 teachings how much boron did you use? It seems
> like a necessary flux at cone 6 but optional at cone 8.
>
> I hope to take a workshop from you one of these days... are you
> planning any trips to the UK?
>
> -- Ken
>
> ----- Original Message -----
> From: "Ron Roy"
> To:
> Sent: Thursday, April 13, 2000 1:24 PM
> Subject: Re: Cone 6 vs. Cone 9 ox
>
> > ----------------------------Original message----------------------------
> > Hi Ken,
> >
> > It is easier to make glazes with "body" at cone 9 because the feldspars are
> > melting well at that temperature. You can also get more silica and alumina
> > in higher fired glazes - this helps make better glass as well.
> >
> > Colour seems to drop off above cone 6 - at least with the brighter colours
> > - or should I say harder to keep bright.
> >
> > I taught for years at cone 8 - which I thought was a good compromise for
> > electric firing. Glazes can be more stable and clay has a better range than
> > at 6.
> >
> > The key here is how much flux you have to add - at any temperature - to get
> > clays and glazes to melt. The less flux the better the range - simply
> > because the melting can proceed slower with less flux.
> >
> > RR
> >
> > >----------------------------Original message----------------------------
> > >I learned how to make pots in "Mingeisotta", hence in the past I've
> > >fired the bulk of my work at cone 10 reduction. For the next 2-3
> > >years however I will be using an electric kiln, and I'm about to
> > >launch into developing new glazes for my functional stoneware.
> > >
> > >To my eye and hand, cone 9 glazes seem more appealing that cone 6;
> > >they seem softer and have more character. And so I wonder, is
> > >this a property of cone 9 fluxes that just can't be duplicated?
> > >Or is it usually possible, using glaze calculation and experiments,
> > >to tweak the recipe and obtain similar results at cone 6?
> > >
> > >And just how hard on the elements is cone 9?
> > >
> > >-- Ken
> > >In sunny Ireland (at least today...)
> >
> > Ron Roy
> > 93 Pegasus Trail
> > Scarborough
> > Ontario, Canada
> > M1G 3N8
> > Evenings 416-439-2621
> > Fax 416-438-7849
> >
| |
|
