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ron/john's book - mastering cone 6..... can i do at cone 5?

updated sun 24 mar 02

 

Karen and Cliff Sandlin on tue 19 mar 02


Hi:



I made 3 of the glazes in Ron/Jon's book: Waterfall Brown, Raspberry,
and Glossy Base II.



Most of my other existing glazes are Cone 5.



I have a Skutt 1018, but it takes me a long time to fill a kiln.



What effect could I expect if I fire the WF, Raspberry and Base II at
Cone 5, slow speed, with a 10 min. hold at the top?



Do you think the glazes would be a little more matt?



Or, is the ONLY way to find out to try this?



Thanks for any help and conjectures/advice.



Karen

John Hesselberth on tue 19 mar 02


on 3/19/02 4:23 PM, Karen and Cliff Sandlin at sandlink@BELLSOUTH.NET wrote:

> What effect could I expect if I fire the WF, Raspberry and Base II at
> Cone 5, slow speed, with a 10 min. hold at the top?

Hi Karen,

With those particular glazes, I doubt you will SEE much difference. But
remember our leaching and durability testing was done on pots fired to cone
6. They will probably not be as durable at cone 5 but the only way to tell
is to test, test, test.

The semimatte bases will almost certainly not be as durable or stable at
cone 5.

Regards,

John

web sites: http://www.masteringglazes.com and http://www.frogpondpottery.com
EMail: john@frogpondpottery.com

"It is, perhaps, still necessary to say that the very best glazes cannot
conceal badly shaped pots..." David Green, Pottery Glazes

Diane Woloshyn on wed 20 mar 02


Hi Karen,

If you use a slow cooling cycle and large cones to moniter, you will probably
find that your kiln is actually going to cone 6. Mine does on just that
cycle and it is a Skutt with a controller. Would bet that your clays will be
fine, although very thin pieces might slump. Try it!

Diane Florida Bird Lady

william schran on thu 21 mar 02


Karen - Have fired all at cone 5 with good results.
Bill

A. Rasmussen on fri 22 mar 02


So if there's problems with certain editions of the
book, which one do we look for without the errors?


--- william schran wrote:
> Karen - Have fired all at cone 5 with good results.
> Bill
>
>
______________________________________________________________________________
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> reached at melpots@pclink.com.


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Nanci Bishof on fri 22 mar 02


Bill,

Does they did good with the ^5 firing of all the glaze recipes in the
Mastering ^6 Glazes book mean they hold up to freeze/thaw, crazing, abrasion
(knife blade), dishwasher, absorption and vinegar tests? Does it mean that
the glazes also still pass the leaching tests at laboratories? Or, does it
mean they appear to have the same surface and color quality in the
photographs? If you tested the glazes to the same standards that Ron and John
did I'd love to know that because my porcelain is a ^5 claybody (Highwater
P5) and it would save me time and money replicating what you already did.

nanci

william schran on fri 22 mar 02


Nanci - Have not done testing as described in text on the glazes
fired at cone 5 and have not tested all glazes in the book at this
cone. My cone 5 is usually flat, with cone 6 bending to about 2
o'clock position. Have only fired "raspberry", "wax wing" & "stormy
blue light". Plan to try out others and will be doing the basic
crazing and vinegar tests. As my students use multiple clay bodies, I
will probably never get around to testing all glazes on all clay
bodies.
Bill



>Bill,
>
>Does they did good with the ^5 firing of all the glaze recipes in the
>Mastering ^6 Glazes book mean they hold up to freeze/thaw, crazing, abrasion
>(knife blade), dishwasher, absorption and vinegar tests? Does it mean that
>the glazes also still pass the leaching tests at laboratories? Or, does it
>mean they appear to have the same surface and color quality in the
>photographs? If you tested the glazes to the same standards that Ron and John
>did I'd love to know that because my porcelain is a ^5 claybody (Highwater
>P5) and it would save me time and money replicating what you already did.
>
>nanci
>
>______________________________________________________________________________
>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.

Snail Scott on fri 22 mar 02


At 01:44 PM 3/22/02 EST, you wrote:
>Does they did good with the ^5 firing of all the glaze recipes...hold up
to tests? Or, does it
>mean they appear to have the same surface and color quality in the
>photographs? If you tested the glazes to the same standards that Ron and John
>did I'd love to know that because my porcelain is a ^5 claybody...


Unless you use the same claybody, and the same firing
cycle, etc, his results won't mean much for you. His
^5 plus soak might actually be equal to Ron&John's ^6.
And glaze fit will be very different for porcelain
than for stoneware. You'll probably still have to
test.

-Snail

L. P. Skeen on fri 22 mar 02


IT's not Ron/John's book that has the errors, it's a Lark book.

L
----- Original Message -----
From: "A. Rasmussen"
To:
Sent: Friday, March 22, 2002 9:09 AM
Subject: Re: Ron/John's book - Mastering Cone 6..... Can I do at Cone 5?


> So if there's problems with certain editions of the
> book, which one do we look for without the errors?
>
>
> --- william schran wrote:
> > Karen - Have fired all at cone 5 with good results.
> > Bill
> >
> >
>
_________________________________________________________________________=
___
__
> > 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.
>
>
> =3D=3D=3D=3D=3D
> "To travel is to live."
> --H.C. Andersen
>
> __________________________________________________
> Do You Yahoo!?
> Yahoo! Movies - coverage of the 74th Academy Awards=AE
> http://movies.yahoo.com/
>
>
_________________________________________________________________________=
___
__
> 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.
>

L. P. Skeen on fri 22 mar 02


Nancy,

John answered this question last week. The glazes were formulated for and
tested at a certain temperature range (ie: cone 6ox). Therefore, if they
are not fired to that temperature, they may not be fully mature and may
leach/craze/otherwise be unfit for food. You will have to test them on your
claybody anyway in order to adjust them to fit.

L
----- Original Message -----
From: "Nanci Bishof"
To:
Sent: Friday, March 22, 2002 1:44 PM
Subject: Re: Ron/John's book - Mastering Cone 6..... Can I do at Cone 5?


> Bill,
>
> Does they did good with the ^5 firing of all the glaze recipes in the
> Mastering ^6 Glazes book mean they hold up to freeze/thaw, crazing,
abrasion
> (knife blade), dishwasher, absorption and vinegar tests? Does it mean that
> the glazes also still pass the leaching tests at laboratories? Or, does it
> mean they appear to have the same surface and color quality in the
> photographs? If you tested the glazes to the same standards that Ron and
John
> did I'd love to know that because my porcelain is a ^5 claybody (Highwater
> P5) and it would save me time and money replicating what you already did.
>
> nanci
>
>
____________________________________________________________________________
__
> 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.
>

Nanci Bishof on sat 23 mar 02


Bill,

Your cone positions sound like the ones I get during a ^5 firing using a bar
shaped cone in the setter. I find them to give truer (they match the witness
cones) readings on firing than the small cones in the setter. I teach Middle
School and would love to switch to mixed glazes vs. commercial ones. Cost and
a greater trust in the safety of the glazes that Ron & John tested are big
factors. I bought the book for use in my classroom. I stress safety of
ingredients, fit to claybody and integrity of the glaze to my students. All
before they get to play in the mud.

Thank you for answering my inquiry,

nanci

Ababi on sat 23 mar 02


I started my ceramic life with a kiln that was hardly firing to 1000C.
When I got my new kiln ( was given as a contributions as I was working
with Bedouin kids and women) I was afraid to go up to 1220, 1200 was
enough, so I thought.
My Neighbor potter ( going to L.A. soon) thinks 1220 is too high.
My ceramic school tried to convinced me to fire in 1240C. She did not
pay for the electricity.
Besides what R&J are telling us: 1220C or ^6 is a language.
Each kiln or country has it's dialect we pass these glazes pretty good
If I can make beautiful glazes in reasonable price, Why to stick to ^5?

By the way, I got ( in my words) electricity measuring tool. I found
out that sometimes bisque to 950C took more electricity than glaze to
or that ^04 was equal or 1$ less than ^6 firing
Yours
Ababi Sharon
Kibbutz Shoval- Israel
Going deeply into glazing
ababisha@shoval.org.il
http://members4.clubphoto.com/ababi306910/
http://www.milkywayceramics.com/cgallery/asharon.htm
http://www.israelceramics.org/



---------- Original Message ----------

>Bill,

>Does they did good with the ^5 firing of all the glaze recipes in the
>Mastering ^6 Glazes book mean they hold up to freeze/thaw, crazing,
>abrasion
>(knife blade), dishwasher, absorption and vinegar tests? Does it mean
>that
>the glazes also still pass the leaching tests at laboratories? Or,
does
>it
>mean they appear to have the same surface and color quality in the
>photographs? If you tested the glazes to the same standards that Ron
>and John
>did I'd love to know that because my porcelain is a ^5 claybody
>(Highwater
>P5) and it would save me time and money replicating what you already
>did.

>nanci

>_______________________________________________________________________
_
>______
>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.