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a little glaze help alabama

updated sun 28 apr 02

 

travis kilgore on thu 11 apr 02


Guys,
I have a glaze mixed up which is a little more mat than i would like for =
it to be what can i add to make it a little more transparent

Soda Feldspar 42%
China Clay 4.%
Benonite 2%
Dolomite 22%
Whiting 3%
zinc oxide 5%
Flint 22%
Cobalt oxide .75 color

Very matt purple blue
Cone 6 oxidation
would like a more Crystalline Matt look as apposed to the flat matt i =
have now.

Ron Roy on sat 13 apr 02


What cone fired to - how far is cone bent?

RR


>I have a glaze mixed up which is a little more mat than i would like for
>it to be what can i add to make it a little more transparent
>
>Soda Feldspar 42%
>China Clay 4.%
>Benonite 2%
>Dolomite 22%
>Whiting 3%
>zinc oxide 5%
>Flint 22%
>Cobalt oxide .75 color
>
>Very matt purple blue
>Cone 6 oxidation
>would like a more Crystalline Matt look as apposed to the flat matt i have
now.

Ron Roy
RR #4
15084 Little Lake Road
Brighton
Ontario
Canada - K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513

travis kilgore on sat 13 apr 02


Cone 6 oxidation
the cone is bent in half in the kiln siter
the watch cone hasn't tiped
----- Original Message -----
From: Ron Roy
To:
Sent: Friday, April 12, 2002 9:40 PM
Subject: Re: A little glaze help Alabama


> What cone fired to - how far is cone bent?
>
> RR
>
>
> >I have a glaze mixed up which is a little more mat than i would like for
> >it to be what can i add to make it a little more transparent
> >
> >Soda Feldspar 42%
> >China Clay 4.%
> >Benonite 2%
> >Dolomite 22%
> >Whiting 3%
> >zinc oxide 5%
> >Flint 22%
> >Cobalt oxide .75 color
> >
> >Very matt purple blue
> >Cone 6 oxidation
> >would like a more Crystalline Matt look as apposed to the flat matt i
have now.
>
> 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.
>

Ian Currie on tue 16 apr 02


Hi Travis

There are a number of possible reasons for your glaze being so matt... the
most likely being that it is simply not adequately matured for what you
want. I think I know what you are aiming for, and there are several things
you can try.

Firstly, if it is an option, you could try firing higher, or just soaking at
the end of the firing - that is holding top temperature for a while to give
things a chance to melt.

Secondly, your glaze is a relatively high-silica glaze. To get less matt,
more shine and a few crystals in it, you need to move to slightly higher
alumina and lower silica. Adding more alumina to increase shine is slightly
counter-intuitive... but it makes sense if you have a glaze that is low in
alumina and high in silica.

Thirdly if you do not wish to fire higher I suspect you need to flux the
glaze more by for example addition of some frit. I think you have
everything else there you need.

More specifically:
1. Reduce the flint and increase the kaolin. ("Reducing" the flint is not
an option if you are trying to save an already mixed up glaze.) Perhaps a
lineblend (3 to 5 glazes max.) from your present glaze to one with about 12%
flint and 8% kaolin. This is taking a transect across one of my grids which
should find it if it is there with the firing you are using.

2. If all these are still matt you probably need to increase the firing
temperature, or alternatively drop the melting point of the glaze by adding
a little frit. Which frit? What have you got? How much? Try 10%. Line
blend in more or less if necessary. This is definitely an option for your
ready-mixed glaze.

You will have to do some testing. You need to find out how much dry
material is in, say, one cup of your glaze suspension... and work out the
maths so you can introduce frit or whatever in your experiments in a way
that is reproducible in the whole batch. You just need to find the ratio of
dry ingredients to wet glaze mix. For example take a cup full, dry it out
and weigh it.

Please do not tell me if your batch of glaze is one pint. Just throw it out
and start again!

>From (currently) Alfred NY... dipping into Clayart when I am able

Ian
http://ian.currie.to/

> From: travis kilgore
> Reply-To: Ceramic Arts Discussion List
> Date: Thu, 11 Apr 2002 19:46:47 -0700
> To: CLAYART@LSV.CERAMICS.ORG
> Subject: A little glaze help Alabama
>
> Guys,
> I have a glaze mixed up which is a little more mat than i would like for
it to
> be what can i add to make it a little more transparent
>
> Soda Feldspar 42%
> China Clay 4.%
> Benonite 2%
> Dolomite 22%
> Whiting 3%
> zinc oxide 5%
> Flint 22%
> Cobalt oxide .75 color
>
> Very matt purple blue
> Cone 6 oxidation
> would like a more Crystalline Matt look as apposed to the flat matt i have
> now.
>
>
____________________________________________________________________________
__
> 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.

travis kilgore on wed 17 apr 02


Ian,
Thank for the glaze input. Travis is my husband and our email account is in
his name sorry for the confussion. I'm Barbara. And don't worry my batch of
glaze is about 10,000 gm. so saving it is a must. I had tested this glaze
earlier and had made some changes to it but some how forgot to make them in
the final batch. I'm going to break this large batch of glaze down into
smaller ones and hopefully find a way to save most of it.
----- Original Message -----
From: Ian Currie
To:
Sent: Tuesday, April 16, 2002 8:46 AM
Subject: Re: A little glaze help Alabama


> Hi Travis
>
> There are a number of possible reasons for your glaze being so matt... the
> most likely being that it is simply not adequately matured for what you
> want. I think I know what you are aiming for, and there are several
things
> you can try.
>
> Firstly, if it is an option, you could try firing higher, or just soaking
at
> the end of the firing - that is holding top temperature for a while to
give
> things a chance to melt.
>
> Secondly, your glaze is a relatively high-silica glaze. To get less matt,
> more shine and a few crystals in it, you need to move to slightly higher
> alumina and lower silica. Adding more alumina to increase shine is
slightly
> counter-intuitive... but it makes sense if you have a glaze that is low in
> alumina and high in silica.
>
> Thirdly if you do not wish to fire higher I suspect you need to flux the
> glaze more by for example addition of some frit. I think you have
> everything else there you need.
>
> More specifically:
> 1. Reduce the flint and increase the kaolin. ("Reducing" the flint is not
> an option if you are trying to save an already mixed up glaze.) Perhaps a
> lineblend (3 to 5 glazes max.) from your present glaze to one with about
12%
> flint and 8% kaolin. This is taking a transect across one of my grids
which
> should find it if it is there with the firing you are using.
>
> 2. If all these are still matt you probably need to increase the firing
> temperature, or alternatively drop the melting point of the glaze by
adding
> a little frit. Which frit? What have you got? How much? Try 10%.
Line
> blend in more or less if necessary. This is definitely an option for your
> ready-mixed glaze.
>
> You will have to do some testing. You need to find out how much dry
> material is in, say, one cup of your glaze suspension... and work out the
> maths so you can introduce frit or whatever in your experiments in a way
> that is reproducible in the whole batch. You just need to find the ratio
of
> dry ingredients to wet glaze mix. For example take a cup full, dry it out
> and weigh it.
>
> Please do not tell me if your batch of glaze is one pint. Just throw it
out
> and start again!
>
> >From (currently) Alfred NY... dipping into Clayart when I am able
>
> Ian
> http://ian.currie.to/
>
> > From: travis kilgore
> > Reply-To: Ceramic Arts Discussion List
> > Date: Thu, 11 Apr 2002 19:46:47 -0700
> > To: CLAYART@LSV.CERAMICS.ORG
> > Subject: A little glaze help Alabama
> >
> > Guys,
> > I have a glaze mixed up which is a little more mat than i would like for
it to
> > be what can i add to make it a little more transparent
> >
> > Soda Feldspar 42%
> > China Clay 4.%
> > Benonite 2%
> > Dolomite 22%
> > Whiting 3%
> > zinc oxide 5%
> > Flint 22%
> > Cobalt oxide .75 color
> >
> > Very matt purple blue
> > Cone 6 oxidation
> > would like a more Crystalline Matt look as apposed to the flat matt i
have
> > now.
> >
> >
____________________________________________________________________________
__
> > 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.
>

Ron Roy on sat 27 apr 02


Hi Travis - I've been out of town for a while so that's why I'm late with
this.

First - I need to know what cone was the guard cone - if it was 6 then we
don't even know if you got to cone 5 - always use a large cone to monitor
your firings - and turn off your kiln when you see it bending - that way
you know what cone the firing got to. You should also use a cone higher in
the sitter - at least a cone 7 if you want to get to cone 6 using a large
cone.

This glaze is not a matte glaze so I am assuming it is matte because it is
underfired.

It is also short of alumina and silica so it is not going to be durable in
use with food.

So we need to see what it looks like at cone 6 for starters and I would
suggest you add frit 3134 in 2% increments - but it's going to start being
shiny and I don't think it's what you want.

RR

>Cone 6 oxidation
>the cone is bent in half in the kiln siter
>the watch cone hasn't tiped
>----- Original Message -----

>> What cone fired to - how far is cone bent?
>>
>> RR
>>
>>
>> >I have a glaze mixed up which is a little more mat than i would like for
>> >it to be what can i add to make it a little more transparent
>> >
>> >Soda Feldspar 42%
>> >China Clay 4.%
>> >Benonite 2%
>> >Dolomite 22%
>> >Whiting 3%
>> >zinc oxide 5%
>> >Flint 22%
>> >Cobalt oxide .75 color
>> >
>> >Very matt purple blue
>> >Cone 6 oxidation
>> >would like a more Crystalline Matt look as apposed to the flat matt i
>have now.

Ron Roy
RR #4
15084 Little Lake Road
Brighton
Ontario
Canada - K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513