LindaBlossom on mon 3 nov 03
>
Hello Ron,
I went back to Ababi's original post and your response to it as I remember
reading it carefully. I attach them below. I couldn't quite figure out the
boron part of your first post since Ababi didn't give a recipe of any kind.
As his request was for hints to do with single firing with paper clay, I
was responding to your answer to him in which you said that paper clay has a
lot of carbon to burn out so slow firing will probably be necessary. I am
stating that I do single fire paperclay and do it very quickly as long as I
am firing thin tiles. I would think that the burning out of the paper would
affect glazes whether I am firing pots or tiles as burning matter would not
know to go out the bottom of a tile vs through the top of it. The theory
that the burning of the paper would create problems when single firing paper
clay fast sounds good but it is that theory that I am not finding to be the
case. In answer to your questions, I do fire on one side and to cone 8; I
would have to check recipes but I don't change my firing based on the glaze
used and I do use a lot of glazes so boron is likely. If you want I can
check.
Linda
>
> I said - high boron glazes at cone 6 - pots are glazed inside and out - if
> the high boron glazes seals over before the carbon gets out - and if iron
> is present - I expect over vitrification of the clay - as Stephen Hill
also
> warns about.
>
> You glaze only one side and the clay is very thin - and you fire to what
> cone 8? - any glazes with high boron? Any iron in the clay?
>
> My answer to Ababi was to warn about possible problems - what don't you
> agree with?
>
> RR
>
>
> >I would love to be able to agree with Ron on all occasions but experience
is
> >proving the above theory to be questionable. I make tiles very thin -
less
> >than a quarter inch - probably about 3/16" and have been firing them in
> >electric at a rate of about 240 C/hr until the kiln slows down to about
160C
> >around the 900C point. Even at the higher temperatures as I approach
cone
> >8, I maintain about 60C per hour. I have not had a problem with the
glazes
> >as a result of anything burning out. I have been making the tiles thin
to
> >eliminate moisture problems. The glazes are turning out really good as I
> >cool about 100C per hour until I reach 1000 and then shut down. The clay
is
> >always paperclay and always single fired.
> >
>
This looks like it could be problematic - especially at cone 6 - if the
boron seals over before the carbon is gone - and it will with higher
amounts of boron in glazes - then I would imagine all kinds of problems.
I noticed in an article by Stephen Hill - on single firing - that care must
be taken to get the combustables out before the glazes seal over - he fires
to cone 10 so there would not be much boron present if any.
Paper clay has a lot of carbon to burn out so slow firing will probably be
necessary.
RR
>Hi!
>I tried to read the book "Single firing" of Fran Tristram. In the
>beginning I enjoyed- latter was too complicated, I mean, if I must read
>a book with a dictionary, I give it up. It is a good book and I have got
>the idea.
>My question is to the PaperClayArters. May you give me hints about
>single firing with paperclay?
>Ababi, back to the list with the repaired computer.
Ababi on tue 4 nov 03
OK
In one of the next firing when I will try the single firing I shall test
on the same board of paperclay different glazes. With and without boron
I do bisque slow up to 500C as Rosette Gault offers. I will do the same
with the single fireing
Ababi Sharon
Glaze addict
Kibbutz Shoval Israel
ababisha@shoval.org.il
http://members4.clubphoto.com/ababi306910
http://www.matrix2000.co.nz/Matrix%20Demo/Ababi.htm
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of
LindaBlossom
Sent: Tuesday, November 04, 2003 5:48 AM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: Single-paper-clay-glazing-answer to Ron
>
Hello Ron,
I went back to Ababi's original post and your response to it as I
remember
reading it carefully. I attach them below. >Hi!
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>I tried to read the book "Single firing" of Fran Tristram. In the
>beginning I enjoyed- latter was too complicated, I mean, if I must read
>a book with a dictionary, I give it up. It is a good book and I have
got
>the idea.
>My question is to the PaperClayArters. May you give me hints about
>single firing with paperclay?
>Ababi, back to the list with the repaired computer.
.
Ron Roy on wed 5 nov 03
Hi Linda,
I am just putting two and two together - If Stephen Hill - who single fires
all his pots to cone 10 - says - treat the first part of a single firing as
you would a bisque then he has learned the hard way.
What he is saying is - when glazes start to seal over - they prevent the
burning out of organics in the clay. If there is iron in the clay then the
iron will reduce and become a flux, cause pinholing and blisters and
overfire the clay.
You did not answer the question - is your clay white? If it is then perhaps
that is part of the reason you are not having a problem. Besides - if one
side is not glazed then the organics can come out the unglazed side easier
than if they were glazed.
The 2nd part of this - at cone 6 there are many glazes that have a lot of
boron - these types of glazes seal over at quite a low temperature - and
can prevent the organics from getting out in ware glazed on both sides.
There may even be some high boron glazes that will not be usable in single
firing - to any temperature because of this.
If we speculate based on what we know we can anticipate problems so that
when they show up we may have some idea about the causes - and find
solutions.
It is about thinking about what we do and accumulating the ways to deal
with our particular ways of working. Knowing that paper clay has extra
carbon in it and that it will never be water tight can lead to appropriate
uses of the material. - knowing the limitations of our materials will help
us decide how to use them.
RR
>I went back to Ababi's original post and your response to it as I remember
>reading it carefully. I attach them below. I couldn't quite figure out the
>boron part of your first post since Ababi didn't give a recipe of any kind.
>As his request was for hints to do with single firing with paper clay, I
>was responding to your answer to him in which you said that paper clay has a
>lot of carbon to burn out so slow firing will probably be necessary. I am
>stating that I do single fire paperclay and do it very quickly as long as I
>am firing thin tiles. I would think that the burning out of the paper would
>affect glazes whether I am firing pots or tiles as burning matter would not
>know to go out the bottom of a tile vs through the top of it. The theory
>that the burning of the paper would create problems when single firing paper
>clay fast sounds good but it is that theory that I am not finding to be the
>case. In answer to your questions, I do fire on one side and to cone 8; I
>would have to check recipes but I don't change my firing based on the glaze
>used and I do use a lot of glazes so boron is likely. If you want I can
>check.
>
>Linda
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
Bobbruch1@AOL.COM on thu 6 nov 03
<<< I am just putting two and two together -
If Stephen Hill - who single fires all his pots to cone 10 - says - treat the
first part of a single firing as you would a bisque then he has learned the
hard way.
<<<burning out of organics in the clay. If there is iron in the clay then the
iron will reduce and become a flux, cause pinholing and blisters and overfire the
clay.
Ron, can slips, engobes or underglazes have any of that "sealant" effect? I
seem to be noticing that with certain glazes, the test tiles often produce
results with no pinholing, while my pieces with slips and undergalzes often show
considerable problems with pinholes.
Thanks, Bob Bruch
Ron Roy on fri 7 nov 03
Hi Bob,
I tend to think not - perhaps it has more to do with the slips, engobes and
underglaze - being more refractory than the clay - are holding back the
melt of the glazes.
It would be easy to confirm this with the slips and engobes - make some
bars of them and fire em to glaze temp and do an absorption test.
Mixing the underglaze with increasing percentages of the glaze you put over
them will tell if more melting will cure the problem.
Maybe just making the over glaze melt more may work well - and/or soaking.
Remember - if refiring does no good or makes pinholes worse - the body is
overfiring for whatever reason - if refiring gets rid of the pinholes the
glaze needs a soak, a higher firing, a slower cool or more melt.
I'll be happy to look at the glaze for you and maybe I can deduce the
problem that way.
RR
><<< I am just putting two and two together -
>If Stephen Hill - who single fires all his pots to cone 10 - says - treat the
>first part of a single firing as you would a bisque then he has learned the
>hard way.
>
><<<>burning out of organics in the clay. If there is iron in the clay then the
>iron will reduce and become a flux, cause pinholing and blisters and
>overfire the
>clay.
>
>Ron, can slips, engobes or underglazes have any of that "sealant" effect? I
>seem to be noticing that with certain glazes, the test tiles often produce
>results with no pinholing, while my pieces with slips and undergalzes
>often show
>considerable problems with pinholes.
>
>Thanks, Bob Bruch
>
>______________________________________________________________________________
>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.
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
Ron Roy on sun 23 nov 03
Hi Ababi,
Thanks for this - you should turn off HTML - turn on plain text by the way.
Both glazes have little boron.
Remember what I said - to the question - any problems single firing glazes
on paper clay to cone 6?
I said - could be with high boron glazes because they seal over faster and
if the carbon is not gone it will be a mess.
If to cone 04 then it will be more difficult.
RR
>No I did not glaze the bottom of the wares..
>About the firing.
>Yehuda Koren offered me this shouldering for the bisque :Until 200C
>the speed had to be 100C in an hour. From 200-500C speed of 200C in an
>hour. At 250C close the peep hole at the top of the kiln. 500full
>firing.
>The manufacturer explained me that when the kiln reaches the 1000C or so
>it slows down itself as it is hard for it to climb- in another word the
>graph turns down a bit.
>On the control panel of the kiln (Israeli made- the best in our market)
>there is a button with numbers 1-8 and the next is maximum.
> (Israeli made- the best in our market) I did: up to200C #5 1/2 on the
>button
>200 C- 500C 8.5# on the button than to maximum soaking 30 minutes on
>top. Going down "almost your way- good isolation.
>
>Now with paperclay I do the (bisque up to 1000C) this way: (So I did in
>this single fire too up to 1220C)
>The leatherhard work: Up to 80 C full heat and dried overnight.
>
>From here to 150C #2 on the button.
>150-200 #5C
>200-300#6
>300-400 #7
>400-450#8
>450-500C #8.5
>at 500C I close the peep hole and fire full speed.
>It is important to know that in 230C the paper is fired.
>Only the big green Hanukah lamp has boron yet I spayed it thick actually
>too thick -the glaze is more beautiful with less heavy application- I
>thought more about you than on the ware- I wanted also to see if the raw
>paperclay would not collapse.
>First glaze thin application:
>FOLLOW KOREN 27 2#
>,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
>
>Cone 6 1201 deg.C. -
>,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
>
>SILICA 31.50
>Calcium Carbonate 12.00
>ENGLISH KAOLIN CC31 13.50
>ZINC OXIDE 10.00
>Nepheline Syenite 10.00
>STRONTIUM CARBONATE 7.00
>FRIT 3110 16.00
>,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
>
> Seger Weight%
>KNO 0.182 5.13%
>CaO 0.365 8.48%
>MgO 0.001 0.01%
>ZnO 0.327 11.02%
>SrO 0.126 5.41%
>Al2O3 0.204 8.61%
>B2O3 0.016 0.46%
>SiO2 2.443 60.87%
>K2O 0.034 1.34%
>Na2O 0.148 3.80%
>Al:Si 11.99
>Expan. 7.74
>ST 367.64
>,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
>
>second glaze heavy application:
> I use Tony Hansen's latest analysis for G.B.
>SPECKLED GREEN
>,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
>
>Cone 6 1222 deg.C. -
>,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
>
>Gerstley Borate 20.00
>Nepheline Syenite 20.00
>FRIT 3110 15.00
>BALL CLAY AK 15.00
>SILICA 30.00
>Copper oxide black 5.00
>Red Iron Oxide 1.50
>Titanium Dioxide 5.00
>,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
>
> Seger Weight%
>KNO 0.418 6.60%
>CaO 0.458 6.07%
>MgO 0.124 1.18%
>Al2O3 0.449 10.80%
>B2O3 0.336 5.52%
>SiO2 4.548 64.55%
>TiO2 0.280 5.28%
>K2O 0.063 1.40%
>Na2O 0.355 5.20%
>Al:Si 10.13
>Expan. 7.48
>ST 338.03
>,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
>
>Hope it helps.
>Ababi Sharon
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
Ababi on sun 23 nov 03
What is a glaze addict?
Like any addict he will be involved in crime to get what he needs!
When I cannot find enough tiles I break a ware and make tiles out of it.
I shall test this matter deeper into the Boron in my next ^6 firing.
Ababi Sharon
Glaze addict
Kibbutz Shoval Israel
ababisha@shoval.org.il
http://ababi.active.co.il
http://www.matrix2000.co.nz/Matrix%20Demo/Ababi.htm
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of Ron Roy
Sent: Sunday, November 23, 2003 7:48 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Single-paper-clay-glazing-answer to Ron
Hi Ababi,
Thanks for this - you should turn off HTML - turn on plain text by the
way.
Both glazes have little boron.
Remember what I said - to the question - any problems single firing
glazes
on paper clay to cone 6?
I said - could be with high boron glazes because they seal over faster
and
if the carbon is not gone it will be a mess.
If to cone 04 then it will be more difficult.
RR
>No I did not glaze the bottom of the wares..
>About the firing.
>Yehuda Koren offered me this shouldering for the bisque :Until 200C
>the speed had to be 100C in an hour. From 200-500C speed of 200C in an
>hour. At 250C close the peep hole at the top of the kiln. 500full
>firing.
>The manufacturer explained me that when the kiln reaches the 1000C or
so
>it slows down itself as it is hard for it to climb- in another word the
>graph turns down a bit.
>On the control panel of the kiln (Israeli made- the best in our market)
>there is a button with numbers 1-8 and the next is maximum.
> (Israeli made- the best in our market) I did: up to200C #5 1/2 on the
>button
>200 C- 500C 8.5# on the button than to maximum soaking 30 minutes on
>top. Going down "almost your way- good isolation.
>
>Now with paperclay I do the (bisque up to 1000C) this way: (So I did in
>this single fire too up to 1220C)
>The leatherhard work: Up to 80 C full heat and dried overnight.
>
>From here to 150C #2 on the button.
>150-200 #5C
>200-300#6
>300-400 #7
>400-450#8
>450-500C #8.5
>at 500C I close the peep hole and fire full speed.
>It is important to know that in 230C the paper is fired.
>Only the big green Hanukah lamp has boron yet I spayed it thick
actually
>too thick -the glaze is more beautiful with less heavy application- I
>thought more about you than on the ware- I wanted also to see if the
raw
>paperclay would not collapse.
>First glaze thin application:
>FOLLOW KOREN 27 2#
>,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
>
>Cone 6 1201 deg.C. -
>,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
>
>SILICA 31.50
>Calcium Carbonate 12.00
>ENGLISH KAOLIN CC31 13.50
>ZINC OXIDE 10.00
>Nepheline Syenite 10.00
>STRONTIUM CARBONATE 7.00
>FRIT 3110 16.00
>,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
>
> Seger Weight%
>KNO 0.182 5.13%
>CaO 0.365 8.48%
>MgO 0.001 0.01%
>ZnO 0.327 11.02%
>SrO 0.126 5.41%
>Al2O3 0.204 8.61%
>B2O3 0.016 0.46%
>SiO2 2.443 60.87%
>K2O 0.034 1.34%
>Na2O 0.148 3.80%
>Al:Si 11.99
>Expan. 7.74
>ST 367.64
>,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
>
>second glaze heavy application:
> I use Tony Hansen's latest analysis for G.B.
>SPECKLED GREEN
>,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
>
>Cone 6 1222 deg.C. -
>,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
>
>Gerstley Borate 20.00
>Nepheline Syenite 20.00
>FRIT 3110 15.00
>BALL CLAY AK 15.00
>SILICA 30.00
>Copper oxide black 5.00
>Red Iron Oxide 1.50
>Titanium Dioxide 5.00
>,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
>
> Seger Weight%
>KNO 0.418 6.60%
>CaO 0.458 6.07%
>MgO 0.124 1.18%
>Al2O3 0.449 10.80%
>B2O3 0.336 5.52%
>SiO2 4.548 64.55%
>TiO2 0.280 5.28%
>K2O 0.063 1.40%
>Na2O 0.355 5.20%
>Al:Si 10.13
>Expan. 7.48
>ST 338.03
>,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
>
>Hope it helps.
>Ababi Sharon
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
________________________________________________________________________
______
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.
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