Winston J. Taylor on thu 30 may 02
according to Peter King at recent workshop, somewhere in the Clayart
archives is a message or reference to a article by Val Cushing about
lowering firing temperatures of cone 8 or 9 glazes to around cone 5 or 6.
Can anyone help me out here? I am not able to find it. Or other sugestions
would be welcome.
Thanks! Winston J. Taylor
Mudkitty on thu 30 may 02
For the Val Cushing article on lowering firing temperatures, see Studio
Potter magazine's website at http://www.studiopotter.org/articles/. About
halfway down the page under Clays and Glazes I think you will find what
you're looking for.
Mudkitty
mudkitty@att.net
In Asheville, where the weather is soft,cool, and beautiful, but we need
rain!!
Ababi on thu 30 may 02
Yes Winston.
There are a page or two in Val Cushing handbook.
From The ^6 glaze list prepared by Don Goodrich was written:
==============================================
SUBSTITUTION ^6 FOR ^10
Simply substitute the potash feldspar for Neph Sy feldspar. Most cone
10 glazes can
be lowered to cone 6 with this simple adjustment.
MAYBE add 10% Gerstley Borate in addition to the substitution.
==============================================
There is also http://www.studiopotter.org/articles/art0009.htm
An article of Val Cushing.
I offer you. First take all the glazes you want to convert and fire
them the way they are, Some glazes have a wide rang.
Ababi Sharon
Kibbutz Shoval- Israel
Glaze addict
ababisha@shoval.org.il
http://members4.clubphoto.com/ababi306910/
http://www.milkywayceramics.com/cgallery/asharon.htm
---------- Original Message ----------
>according to Peter King at recent workshop, somewhere in the Clayart
>archives is a message or reference to a article by Val Cushing about
>lowering firing temperatures of cone 8 or 9 glazes to around cone 5 or
>6.
>Can anyone help me out here? I am not able to find it. Or other
>sugestions
>would be welcome.
>Thanks! Winston J. Taylor
>________________________________________________________________________
>______
>Send postings to clayart@lsv.ceramics.org
>You may look at the archives for the list or change your subscription
>settings from http://www.ceramics.org/clayart/
>Moderator of the list is Mel Jacobson who may be reached at
>melpots@pclink.com.
Paul Lewing on thu 30 may 02
on 5/30/02 5:50 AM, Winston J. Taylor at winston_taylor@HOTMAIL.COM wrote:
> somewhere in the Clayart
> archives is a message or reference to a article by Val Cushing about
> lowering firing temperatures of cone 8 or 9 glazes to around cone 5 or 6.
> Can anyone help me out here? I am not able to find it. Or other sugestions
> would be welcome.
Winston, I've tried many times to make cone 10 glazes go down to cone 5, and
I must say, it almost never works. If the original cone 10 recipe has lots
of alumina and silica, it's sometimes possible, but often, there's just not
enough of those available to take out. You often can take out all the clay
and all the flint, and you still haven't gotten it down to a recipe that
will fire at cone 5. You very well might be able to go down from cone 8 to
cone 6, but more than two cones is usually a problem. You end up having to
adjust the balance of fluxes toward more active fluxes, or adding boron, and
then you've got a whole new glaze.
I don't know if you're trying to do this too, but often people who make this
temperature switch are also switching from gas to electric, and that switch
will cause more problems in duplicating effects than the temperature switch
will.
Please don't let me discourage you from doing the testing, though. In some
cases, you might get spectacular results. Just don't expect many glazes to
respond well to this.
Paul Lewing, Seattle
Ian Currie on fri 31 may 02
Hi again Paul
>
> Winston, I've tried many times to make cone 10 glazes go down to cone 5,
and
> I must say, it almost never works.
This is my experience too, where one is trying to convert just one glaze
recipe using some rule of thumb and re-calculating using Seger formula or
oxide weight %. The method I outlined in a post earlier today often works
quite well... it's the best method I've been able to come up with.
You are correctly hinting at the maze of variables one is faced with in
making such a big change from, say, cone 10 to cone 6. Using the grid in
this way we are taking advantage of compensating variables balancing out.
Change just one thing, and you will often lose the glaze. However if you
change two or more things at the same time they will sometime balance out
(compensate) to give the same or similar glaze. Two of the more important
compensating variables are alumina and silica. And the grid, which varies
these two, will often reveal a location with a good mid-fire replication,
and show the major trade-offs at the same time.
Usually one can not translate stoneware glazes to earthenware temperatures
(e.g. cone 02). They are too different, especially the virtual lack of a
clay/glaze interface at the lower temperature. This layer has a major
influence on the quality of many high-fire and mid-fire glazes.
Clayart is taking over my life again, after less than a week! I think I am
going to have to pull my head in for a while!
Cheers
Ian
http://ian.currie.to/
Alex Solla on fri 31 may 02
Ian-
While I have to admit I definitely understand wanting
to tuck your head back in for a bit, I will say
forthrightly that I will miss your knowledge in my
daily email. Having missed your talk at USU and again
at SUNY earlier this year I am bummed. I keep hoping
to sit in on a workshop.
Your explanation of your methods of testing have been
so helpful and influential. After doing only a few
sets of glaze runs, I still marvel at how differently
I think about glazes.... there is never ONE glaze. But
a set instead. Thank you.
Alexander Solla
Cold Springs Studio
4088 Cold Springs Road
Trumansburg, NY 14886
--- Ian Currie wrote:
> Hi again Paul
> >
> > Winston, I've tried many times to make cone 10
> glazes go down to cone 5, and
> > I must say, it almost never works.
>
> This is my experience too, where one is trying to
> convert just one glaze
> recipe using some rule of thumb and re-calculating
> using Seger formula or
> oxide weight %. The method I outlined in a post
> earlier today often works
> quite well... it's the best method I've been able to
> come up with.
>
> You are correctly hinting at the maze of variables
> one is faced with in
> making such a big change from, say, cone 10 to cone
> 6. Using the grid in
> this way we are taking advantage of compensating
> variables balancing out.
> Change just one thing, and you will often lose the
> glaze. However if you
> change two or more things at the same time they will
> sometime balance out
> (compensate) to give the same or similar glaze. Two
> of the more important
> compensating variables are alumina and silica. And
> the grid, which varies
> these two, will often reveal a location with a good
> mid-fire replication,
> and show the major trade-offs at the same time.
>
> Usually one can not translate stoneware glazes to
> earthenware temperatures
> (e.g. cone 02). They are too different, especially
> the virtual lack of a
> clay/glaze interface at the lower temperature. This
> layer has a major
> influence on the quality of many high-fire and
> mid-fire glazes.
>
> Clayart is taking over my life again, after less
> than a week! I think I am
> going to have to pull my head in for a while!
>
> Cheers
>
> Ian
> http://ian.currie.to/
>
>
____________________________________________________________________________
__
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change
> your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be
> reached at melpots@pclink.com.
__________________________________________________
Do You Yahoo!?
Yahoo! - Official partner of 2002 FIFA World Cup
http://fifaworldcup.yahoo.com
Winston J. Taylor on fri 31 may 02
To everyone who has responded to my question about lowering firing temps
from cone 9 to 5 or 6: THANK YOU!...I am the first to admit that by choice
I am an artist and potter, not a chemist, but there times I wish I knew a
little more about glaze calculation. "Mud Kitty" led me right to the
article and I think what I will do instead of monkeying around with my old
glazes is just start testing some already formulated to this temp. Comments
by others have indicated that that may be simpler... again thanks everyone!
Winston J. Taylor
| |
|
