Khaimraj Seepersad on wed 26 jul 00
Greetings to All ,
Bruce ,
I would also add -- Don't try to frit the Colemanite either . As one of
those
unfortunates , who tried to use the compound , and had it flying out of
my 4 x 6 x 6 inch Frit / Test Kiln . I lost all of the coil and had melt
spots
all over the blocks , with more appearing as the colemanite powder ,
melted here and there , all willy nilly .
By the way , did you try Bert Cool's ulexite , and plasticity enhancer ?
I saw your reprint the article ,
Khaimraj
-----Original Message-----
From: Michael Banks
To: CLAYART@LSV.CERAMICS.ORG
Date: 26 July 2000 6:58
Subject: response ability/colemanite
>Bruce,
>
>A lot of people have had trouble from using colemanite in glazes. The
>problem is, colemanite contains a lot of water of crystallisation and this
>water has a habit of releasing suddenly. If there is a significant
>proportion of colemanite in the glaze, it can blow it clean off the pot. I
>think it is fair to say that a large majority of the potters who tried
>colemanite have abandoned this material to save their shelves. I'm one of
>them and I consider that dumping the colemanite is a entirely reasonable
>response, especially since identical results are available from using
>calcium borate frit, a totally anhydrous material and similar results can
be
>got from the better-behaved gerstley borate.
Michael Banks on wed 26 jul 00
Bruce,
A lot of people have had trouble from using colemanite in glazes. The
problem is, colemanite contains a lot of water of crystallisation and this
water has a habit of releasing suddenly. If there is a significant
proportion of colemanite in the glaze, it can blow it clean off the pot. I
think it is fair to say that a large majority of the potters who tried
colemanite have abandoned this material to save their shelves. I'm one of
them and I consider that dumping the colemanite is a entirely reasonable
response, especially since identical results are available from using
calcium borate frit, a totally anhydrous material and similar results can be
got from the better-behaved gerstley borate.
Therefore I was surprised to see that you weighed-in recently with some
fairly erroneous advice. And I'm surprised that you gave Ababi a hard time
for wanting to chuck the material. But now I'm absolutely gob-smacked to
hear that you had never even used colemanite....
Michael Banks,
Nelson,
NZ
----- Original Message -----
From: Bruce Gioia
> Dear Ababi,
> That you find me annoying...
> I can understand. (many do)
> But in this case it is of your own design.
> You want to teach but not be taught.
> You want to share but also withhold that right from others.... (snip)
> Regarding colemanite... I've not worked with it as of yet!
> I just don't like to see materials or people discounted offhand (snip)
Bruce Gioia on wed 26 jul 00
----- Original Message -----
From: Michael Banks
A lot of people have had trouble from using colemanite in glazes
__________________________
Well Mike ,
this is all interesting news.
Would calcining provide any relief
from these irritating bad habits of colemanite?...
I was also warned off list that the turkey source
is not a good option either as it has gypsum contamination.
Just think...if I hadn't opened my big mouth
I might of missed out on all this interesting information.
Having come across so many recipes calling for it...
I am also "gobsmacked" that it has been used at all.
Thanks Mike
Merrily yours,
Bruce
From:
Khaimraj Seepersad on fri 28 jul 00
Hello to All ,
Bruce ,
if your supplies are limited / contaminated or otherwise . Learning
to make a Frit , will make life easy . [ you will need a ball mill and
2 sieves - 200 and 325 mesh and a dahl grinder ]
The Colemanite when heated , steams and spits --- I believe the
source of my trouble child was the Middle East --- perhaps best
to leave this alone .
When I first started making Frits , I began with Ulexite , the
information came from the back of the Hamers' book . I just added
on clay and silica to stabilise . Ulexite is unfortunately , soluble in
warm to hot water , so many of my pots developed " fur " on their
exteriors and glaze spots when bisque fired - chuckle.
We then advanced by reading Parmelee , and the Hamer more
closely .Learning the technique of Soft Frit + Hard Frit or Borate
Frit + Feldspar and so on.
If you design the Man made Gerstley Borate to carry Strontium
and some Magnesium oxide . Glazes are very easy for under
1000 deg. C , using up to 70 % Feldspar and with more than
adequate Al203 or Si02 .
It is much easier for me to pop down to the Pharmaceutical Supplier
and just buy Boric Acid , Soda Ash . Strontium Carbonate and
Magnesium Oxide , I get from away than to buy real Gerstley Borate ,
which has too much calcium for lower temperatures [ all your glazes
end up with white out . ]
However , even if I worked at higher temperatures , I would still
source Strontium Carbonate , as I like the easier fusion .
These are clear glazes , that I am talking about .
I understand the lure and immediacy of High Fire , as I am presently ,
building another test kiln [ interior 4 x 6 x 6 inches ] , to start learning
about melting ash , etc. Nothing to frit , ball mill or prepare , the heat
does it all - chuckle .
I will be continuing my work on small one man teapots , cups and
bowls [ think Yi Xing ] .
If you ever need help learning to frit , let me know , or if you need
balanced formulas for low temperatures .
I just finished , doing some new glazes with wax surfaces , and
a beautiful soft river stone glaze . Using Cullet , Perlite and Man
Made Gerstley Borate . I have everyone in the house cuddling and
touching the glazed shapes --- it is so humorous .
You can learn quite a great deal about Oxides from fritting . I have
produced , some beautiful Celadons [ alas alkaline unstable ] ,
blues , changing to delicate greens , and then observing how each
alkaline earth alters the green . Or adding small quantities of Iron
Oxide and watching the Titanium Dioxide turn it to clear Citrine .
Then there is Phosphorous .
What ever you decide , I wish you the best .
Last point -
I treat B203 as poisonous material , and do not use any glaze
with it as a food glaze . For food I use a pure Alkaline Glaze ,
which you can find in the " new " Parmelee , under the table
Art Glazes. There are 2 , one is for 983 deg.c [ orton small cone 08 ]
and 900 deg.c [ orton small cone 010 , used because the earlier
cones seem to be averaged in their range - this makes sure ]
Silica content is between 61 to 69 % .
Stay well ,
Khaimraj
-----Original Message-----
From: Bruce Gioia
To: CLAYART@LSV.CERAMICS.ORG
Date: 27 July 2000 20:16
Subject: Re: response ability/colemanite
>----- Original Message -----
>From: Khaimraj Seepersad
>
>> I would also add -- Don't try to frit the Colemanite either.
>________________________
>
>----- Original Message -----
>From: Michael Banks
>
>>Commercial calcium borate frits though, are formulated with some
>> silica and alumina to reduce solubility and rehydration
>________________________
>
>Khaimraj... I'm assuming you were testing a straight colemanite melt.(?)
>Would Michael's mention of a commercial blend, together with silica and
>alumina give better results...maybe at slower rate of heat rise?
>
>Without reliable sources in a developing country...
>I will be needing to resource my own materials from various suppliers.
>Things are not only full of contamination
>but to compound the situation,
>Adulteration with cheaper products is a problem
>
>I just don't feel comfortable unless I know what I'm dealing with...
>hence my desire to make things myself.
>Particularly frits will be something I look foreward to.
>I can realize a degree of stability
>when I know what is happening.
>
>
>> By the way , did you try Bert Cool's ulexite , and plasticity enhancer ?
>
>No I have not tried it yet...
>I'm about to go into an intensive effort
>to to complete my studio and aquire my materials.
>The ulexates will be one of my first experiments...
>Though my ideas while on the list have been subjected
>to a great deal of fluxing action [g] and I am somewhat vague or
>at least uncertain in which direction I want to go.
>This fu-fu raku is starting to nag me,
>and the salt/soda shino carbon trap,high fire, wood stuff
>is a seed that feels to be germinating...
>besides the fact that my pots are not suited to my old glazes.
>(which I'm feeling would be unwise to try and recreate here anyhow)
>Also the thread on working within limitations
>has me thinking to focus around my local materials scope.
>So the borates (low fire(?) may not play such an important role as I had
>presumed as less as a few days ago!
>But plasticity enhancer, thixotropic, sintered slip,
>glaze addition etc sounds promising...
>I just like to do reactions and stuff too so
>lets see...
>
>Bruce
>
>ps. I would like to add that I appreciate
>the list at large for the great deal of stimulation,
>focus, direction and distraction [g] that has been afforded me...
>Thanks
>
>
>
>.
>>
>
>___________________________________________________________________________
___
>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.
>
Bruce Gioia on fri 28 jul 00
----- Original Message -----
From: Khaimraj Seepersad
> I would also add -- Don't try to frit the Colemanite either.
________________________
----- Original Message -----
From: Michael Banks
>Commercial calcium borate frits though, are formulated with some
> silica and alumina to reduce solubility and rehydration
________________________
Khaimraj... I'm assuming you were testing a straight colemanite melt.(?)
Would Michael's mention of a commercial blend, together with silica and
alumina give better results...maybe at slower rate of heat rise?
Without reliable sources in a developing country...
I will be needing to resource my own materials from various suppliers.
Things are not only full of contamination
but to compound the situation,
Adulteration with cheaper products is a problem
I just don't feel comfortable unless I know what I'm dealing with...
hence my desire to make things myself.
Particularly frits will be something I look foreward to.
I can realize a degree of stability
when I know what is happening.
> By the way , did you try Bert Cool's ulexite , and plasticity enhancer ?
No I have not tried it yet...
I'm about to go into an intensive effort
to to complete my studio and aquire my materials.
The ulexates will be one of my first experiments...
Though my ideas while on the list have been subjected
to a great deal of fluxing action [g] and I am somewhat vague or
at least uncertain in which direction I want to go.
This fu-fu raku is starting to nag me,
and the salt/soda shino carbon trap,high fire, wood stuff
is a seed that feels to be germinating...
besides the fact that my pots are not suited to my old glazes.
(which I'm feeling would be unwise to try and recreate here anyhow)
Also the thread on working within limitations
has me thinking to focus around my local materials scope.
So the borates (low fire(?) may not play such an important role as I had
presumed as less as a few days ago!
But plasticity enhancer, thixotropic, sintered slip,
glaze addition etc sounds promising...
I just like to do reactions and stuff too so
lets see...
Bruce
ps. I would like to add that I appreciate
the list at large for the great deal of stimulation,
focus, direction and distraction [g] that has been afforded me...
Thanks
.
>
Sharon31 on sat 29 jul 00
A few more words!
I thought, did not know exactly , that "something" Gypsum , or water flies
away from the collemanite. So being smarter than this mineral I 'calcined'
it to 210C, I knew the B2O3 has a very low melting point. I think we can use
it in very small amounts, but knowing that it might damage our kilns
To Bruce:
If you really want to try this material, do it in a saggar!
But if the reason is that you want to try, Like I do, many times, DIFFERENT
materials, than there are a lot if them around.Just be careful from the
nasty ones!
I suggest starting with Potter's Geology of Eric Row and if you want I can
send some of my experiment's subjects.
Ababi
sharon@shoval.org.il
http://www.israelceramics.org/main.asp?what=gallery
http://www.milkywayceramics.com/cgallery/asharon.htm
----- Original Message -----
From: Khaimraj Seepersad
To:
Sent: Friday, July 28, 2000 06:13
Subject: Re: response ability/colemanite
> Hello to All ,
>
> Bruce ,
>
> if your supplies are limited / contaminated or otherwise . Learning
> to make a Frit , will make life easy . [ you will need a ball mill and
> 2 sieves - 200 and 325 mesh and a dahl grinder ]
>
> The Colemanite when heated , steams and spits --- I believe the
> source of my trouble child was the Middle East --- perhaps best
> to leave this alone .
>
> When I first started making Frits , I began with Ulexite , the
> information came from the back of the Hamers' book . I just added
> on clay and silica to stabilise . Ulexite is unfortunately , soluble in
> warm to hot water , so many of my pots developed " fur " on their
> exteriors and glaze spots when bisque fired - chuckle.
>
> We then advanced by reading Parmelee , and the Hamer more
> closely .Learning the technique of Soft Frit + Hard Frit or Borate
> Frit + Feldspar and so on.
> If you design the Man made Gerstley Borate to carry Strontium
> and some Magnesium oxide . Glazes are very easy for under
> 1000 deg. C , using up to 70 % Feldspar and with more than
> adequate Al203 or Si02 .
>
> It is much easier for me to pop down to the Pharmaceutical Supplier
> and just buy Boric Acid , Soda Ash . Strontium Carbonate and
> Magnesium Oxide , I get from away than to buy real Gerstley Borate ,
> which has too much calcium for lower temperatures [ all your glazes
> end up with white out . ]
> However , even if I worked at higher temperatures , I would still
> source Strontium Carbonate , as I like the easier fusion .
> These are clear glazes , that I am talking about .
>
> I understand the lure and immediacy of High Fire , as I am presently ,
> building another test kiln [ interior 4 x 6 x 6 inches ] , to start
learning
> about melting ash , etc. Nothing to frit , ball mill or prepare , the heat
> does it all - chuckle .
> I will be continuing my work on small one man teapots , cups and
> bowls [ think Yi Xing ] .
>
> If you ever need help learning to frit , let me know , or if you need
> balanced formulas for low temperatures .
> I just finished , doing some new glazes with wax surfaces , and
> a beautiful soft river stone glaze . Using Cullet , Perlite and Man
> Made Gerstley Borate . I have everyone in the house cuddling and
> touching the glazed shapes --- it is so humorous .
>
> You can learn quite a great deal about Oxides from fritting . I have
> produced , some beautiful Celadons [ alas alkaline unstable ] ,
> blues , changing to delicate greens , and then observing how each
> alkaline earth alters the green . Or adding small quantities of Iron
> Oxide and watching the Titanium Dioxide turn it to clear Citrine .
> Then there is Phosphorous .
>
> What ever you decide , I wish you the best .
>
> Last point -
> I treat B203 as poisonous material , and do not use any glaze
> with it as a food glaze . For food I use a pure Alkaline Glaze ,
> which you can find in the " new " Parmelee , under the table
> Art Glazes. There are 2 , one is for 983 deg.c [ orton small cone 08 ]
> and 900 deg.c [ orton small cone 010 , used because the earlier
> cones seem to be averaged in their range - this makes sure ]
> Silica content is between 61 to 69 % .
> Stay well ,
> Khaimraj
>
>
>
>
>
>
>
>
>
> -----Original Message-----
> From: Bruce Gioia
> To: CLAYART@LSV.CERAMICS.ORG
> Date: 27 July 2000 20:16
> Subject: Re: response ability/colemanite
>
>
> >----- Original Message -----
> >From: Khaimraj Seepersad
> >
> >> I would also add -- Don't try to frit the Colemanite either.
> >________________________
> >
> >----- Original Message -----
> >From: Michael Banks
> >
> >>Commercial calcium borate frits though, are formulated with some
> >> silica and alumina to reduce solubility and rehydration
> >________________________
> >
> >Khaimraj... I'm assuming you were testing a straight colemanite melt.(?)
> >Would Michael's mention of a commercial blend, together with silica and
> >alumina give better results...maybe at slower rate of heat rise?
> >
> >Without reliable sources in a developing country...
> >I will be needing to resource my own materials from various suppliers.
> >Things are not only full of contamination
> >but to compound the situation,
> >Adulteration with cheaper products is a problem
> >
> >I just don't feel comfortable unless I know what I'm dealing with...
> >hence my desire to make things myself.
> >Particularly frits will be something I look foreward to.
> >I can realize a degree of stability
> >when I know what is happening.
> >
> >
> >> By the way , did you try Bert Cool's ulexite , and plasticity enhancer
?
> >
> >No I have not tried it yet...
> >I'm about to go into an intensive effort
> >to to complete my studio and aquire my materials.
> >The ulexates will be one of my first experiments...
> >Though my ideas while on the list have been subjected
> >to a great deal of fluxing action [g] and I am somewhat vague or
> >at least uncertain in which direction I want to go.
> >This fu-fu raku is starting to nag me,
> >and the salt/soda shino carbon trap,high fire, wood stuff
> >is a seed that feels to be germinating...
> >besides the fact that my pots are not suited to my old glazes.
> >(which I'm feeling would be unwise to try and recreate here anyhow)
> >Also the thread on working within limitations
> >has me thinking to focus around my local materials scope.
> >So the borates (low fire(?) may not play such an important role as I had
> >presumed as less as a few days ago!
> >But plasticity enhancer, thixotropic, sintered slip,
> >glaze addition etc sounds promising...
> >I just like to do reactions and stuff too so
> >lets see...
> >
> >Bruce
> >
> >ps. I would like to add that I appreciate
> >the list at large for the great deal of stimulation,
> >focus, direction and distraction [g] that has been afforded me...
> >Thanks
> >
> >
> >
> >.
> >>
> >
>
>___________________________________________________________________________
> ___
> >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.
> >
>
>
____________________________________________________________________________
__
> 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.
| |
|
