Joan & Tom Woodward on mon 8 apr 02
Elva - I prefer to apply underglazes to greenware, and then the clear on the
bisque. Much easier to handle that way. But if I have any reason to
believe the piece may be defective (i.e. maybe a small crack that I have
tried to repair), I'll bisque first rather than risk wasting the effort only
to have the piece not survive the bisque firing intact. Of course, it can
still fail in the glaze firing. I'm even conservative enough to refire the
bisqueware newly underglazed at 06 before putting on the clear and firing to
6..
Joan who just got some more promising test results to be reported on
post-vinegar testing!
-----
Elva Winter on mon 8 apr 02
I want to try to use underglazes, and would like to know from you folks who
use them:
1. Is it better to put them on greenware, then to fire the greenware, and
then to apply a clear glaze to that bisqued product and fire to cone 6, the
firing cone of my clay, or to
2) Apply the underglazes to bisqued ware and immediately apply a clear
glaze, then fire to cone 6? (once I had done it this way but the clear glaze
did not adhere to all of the underglaze through the firing).
3) Or is there a third and better way?
Thanks for your help.
Elvajoan, a beginner potter in PA, and, always a beginner, in life.
Judith Frederick on tue 9 apr 02
Elvajoan,
I have personally done both ways you list. the third is to apply underglaze
to bisqueware and fire to bisque again, then clear glaze and fire to cone
temperature. What I use to make the decision is the following
considerations:
1) do I need to fire the greenware because it is fragile?
2) will applying clear glaze over underglaze without firing in between smear
the detail of the underglaze?
In my experience all ways have worked. I have however, had underglaze peel
of of bisqueware (which is the way the teacher said he was taught to do it).
I personally liked applying underglaze to greenware before it is bone dry
but well into the leather hard stage. I have also put the underglaze and the
clear glaze on greenware on low fire clay.
It really depends on what you want to achieve with your underglaze.
Judy in Baltimore
(I began clay in a very unconventional method and the college teachers are
always saying "really, you've done that and it worked!?") Hope this helps
you decide.
_________________________________________________________________
Join the world’s largest e-mail service with MSN Hotmail.
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Ruth Jamieson on tue 9 apr 02
Hi Elva and all
I've been using underglazes since I began making pots. I was a painter
before starting in clay and couldn't keep from painting on my pots. I've
also used all three methods discussed so far. Another tip I got from Keith
Campbell, who I was lucky to study with. When mixing my underglazes, I use
water of course, but I also add a bit of the clear glaze I'm going to use
over it later. It helps the underglaze to adhere to the pot, but it also
helps the clear glaze to adhere without crawling during the glaze firing.
I have had nearly 100% success with this method. I really don't worry
about problems with underglazing at all since I started doing this.
Have a good day in the clay and take care.
Ruth Jamieson
North Bay Ontario Canada
Michele Williams on tue 9 apr 02
Ruth,
What's your ratio of clear glaze to underglaze? Are you working at low-,
mid-, or highfire?
Michele Williams
iandol on wed 10 apr 02
Dear Elva Winter,
You say << want to try to use underglazes, and would like to know from =
you folks who use them:>>
In my opinion it is better to put undergalze colour decoration on =
greenware, mixed with a little of your clay or a recommended flux which =
will not cause the decoration to become impervious during bisque firing, =
then follow the process as you describe it. This method ensures adhesion =
and prevents bleeding.
Please remember that some stains are unstable if fired in reduction.
Wishing you every success,
Ivor Lewis.
vince pitelka on wed 10 apr 02
Ivor wrote:
"In my opinion it is better to put undergalze colour decoration on
greenware, mixed with a little of your clay or a recommended flux which will
not cause the decoration to become impervious during bisque firing, then
follow the process as you describe it. This method ensures adhesion and
prevents bleeding."
Ivor -
This might be one of those examples of different use of terminology in the
US versus elsewhere. When we refer to underglazes in the US, we are
generally referring to the commercially made products, and they are true
engobes, designed for application to bone-dry or bisque-fired wares, and you
would not want to add any other ingredients under any circumstances.
Best wishes -
- Vince
Vince Pitelka
Appalachian Center for Crafts
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
Home - vpitelka@dtccom.net
615/597-5376
Work - wpitelka@tntech.edu
615/597-6801 ext. 111, fax 615/597-6803
http://www.craftcenter.tntech.edu/
Earl Brunner on wed 10 apr 02
Vince, while this is true that they already come with some "body" to them, I can't
imagine what kind of problem you would have adding them to some clay other than
diluting the strength a bit. I usually add colorant oxides, stains or even
underglaze (either by itself ot mixed with other colorants) with some of the scrape
or previously dried out portions of Coleman Porcelain (I get mine from Aardvark).
The really great thing about putting stains, oxides or underglazes onto green pots
(especially if they are leather hard or wetter) is that the colorant of choice will
brush on and flow better. The surface isn't dry and sucking up moisture. I
frequently do this on the inside of open forms like bowls or plates. It has the
added advantage of being easy to remove and redo if your brush hand isn't connected
to your brain right the first time.
vince pitelka wrote:
> Ivor wrote:
> "In my opinion it is better to put undergalze colour decoration on
> greenware, mixed with a little of your clay or a recommended flux which will
> not cause the decoration to become impervious during bisque firing, then
> follow the process as you describe it. This method ensures adhesion and
> prevents bleeding."
>
> Ivor -
> This might be one of those examples of different use of terminology in the
> US versus elsewhere. When we refer to underglazes in the US, we are
> generally referring to the commercially made products, and they are true
> engobes, designed for application to bone-dry or bisque-fired wares, and you
> would not want to add any other ingredients under any circumstances.
> Best wishes -
> - Vince
--
Earl Brunner
http://coyote.accessnv.com/bruec
mailto:bruec@anv.net
vince pitelka on thu 11 apr 02
> Vince, while this is true that they already come with some "body" to them,
I can't
> imagine what kind of problem you would have adding them to some clay other
than
> diluting the strength a bit. I usually add colorant oxides, stains or
even
> underglaze (either by itself ot mixed with other colorants) with some of
the scrape
> or previously dried out portions of Coleman Porcelain (I get mine from
Aardvark).
>
> The really great thing about putting stains, oxides or underglazes onto
green pots
> (especially if they are leather hard or wetter) is that the colorant of
choice will
> brush on and flow better. The surface isn't dry and sucking up moisture.
I
> frequently do this on the inside of open forms like bowls or plates. It
has the
> added advantage of being easy to remove and redo if your brush hand isn't
connected
> to your brain right the first time.
>
> vince pitelka wrote:
>
> > Ivor wrote:
> > "In my opinion it is better to put undergalze colour decoration on
> > greenware, mixed with a little of your clay or a recommended flux which
will
> > not cause the decoration to become impervious during bisque firing, then
> > follow the process as you describe it. This method ensures adhesion and
> > prevents bleeding."
> >
> > Ivor -
> > This might be one of those examples of different use of terminology in
the
> > US versus elsewhere. When we refer to underglazes in the US, we are
> > generally referring to the commercially made products, and they are true
> > engobes, designed for application to bone-dry or bisque-fired wares, and
you
> > would not want to add any other ingredients under any circumstances.
> > Best wishes -
> > - Vince
>
> --
> Earl Brunner
> http://coyote.accessnv.com/bruec
> mailto:bruec@anv.net
>
>
____________________________________________________________________________
__
> 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.
>
vince pitelka on thu 11 apr 02
> Vince, while this is true that they already come with some "body" to them,
I can't
> imagine what kind of problem you would have adding them to some clay other
than
> diluting the strength a bit. I usually add colorant oxides, stains or
even
> underglaze (either by itself ot mixed with other colorants) with some of
the scrape
> or previously dried out portions of Coleman Porcelain (I get mine from
Aardvark).
Earl -
Well, I learn something new about every day. In all my years in clay I have
never heard of anyone adding materials to commercial underglazes, but
apparently some people do! I still cannot see the reason, unless you are
just diluting the underglaze to get a softer color. But I do not understand
why you would want to use commercial underglaze on wet or leather-hard clay.
Why use a relatively expensive commercial underglaze, when for far less
money you can mix up slips colored with oxides or mason stains?
Best wishes -
- Vince
Vince Pitelka
Appalachian Center for Crafts
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
Home - vpitelka@dtccom.net
615/597-5376
Work - wpitelka@tntech.edu
615/597-6801 ext. 111, fax 615/597-6803
http://www.craftcenter.tntech.edu/
Earl Brunner on thu 11 apr 02
Well, it's not like I use a huge amount of it. What I do use is usually
done in a
kind of Majolica style brush work on porcelain at cone 10-11. So I usually
stick
to underglazes that I think won't burn out at that temp. Some of the
greens,
blues....
and you about gave the reason there. I can moderate the colors away from
the raw
oxide color. I could no doubt use mason stains and get similar or the same
results.
And I do use them in combination with colored slips that i mix from recipes
using
the standard colorant oxides. For me its a little easier to grab a small
container
of underglaze than to buy the mason stains right now. I might go that way
down the
road. I figured my initial out lay for the stains would be more than for a
container of underglaze from time to time.
vince pitelka wrote:
> Well, I learn something new about every day. In all my years in clay I
have
> never heard of anyone adding materials to commercial underglazes, but
> apparently some people do! I still cannot see the reason, unless you are
> just diluting the underglaze to get a softer color. But I do not
understand
> why you would want to use commercial underglaze on wet or leather-hard
clay.
> Why use a relatively expensive commercial underglaze, when for far less
> money you can mix up slips colored with oxides or mason stains?
--
Earl Brunner
http://coyote.accessnv.com/bruec
mailto:bruec@anv.net
iandol on thu 11 apr 02
Dear vince,
How can I argue with that assessment?
But perhaps it is better not to make an assumption that a generality =
holds good when someone asks a question on Clayart. Not all people have =
access to ready made's from a supplier just around the corner. Even =
those who have may prefer the challenge of finding their own way rather =
than relying on what can be taken from the shelf and just used.
Best regards,
Ivor
Michele Williams on fri 12 apr 02
> Why use a relatively expensive commercial underglaze, when for far less
> money you can mix up slips colored with oxides or mason stains?
1. Because you're at a school where you only have so long to complete X
number of projects that meet Y number of criteria, and mixing stuff slows
you down
2. Because you don't have all the ingredients and may never have them
3. Because you don't know what you're doing when you try to mix up all this
stuff that is foreign to beginners in the art of ceramics
4. Because you have NO idea what kind of result you're going to get without
testing first and our society has not been cultured on patience or anything
like it
5. Because commercial products at least come with a color chart and you can
say, "Oh, there, I like that one."
6. Because naively you think commercial products are going to come out just
like the little ol' color chart (that the printer's color filter printed out
all wrong!)
7. Because you've never done it and truth be told, you're kind of scared
you'll make a mistake (like you'd die from an underglaze mistake)
8. Because you are lazier than egg whites and won't stand up alone without
a beating, never mind take initiative
9. Because it's there
Did I miss anything?
Cindi Anderson on fri 12 apr 02
I have one answer. If you are making a lot of a certain color, or if you
are using the same clay body all the time (so clay body slip is readily
available), then stains might make more sense. But many people want just a
small amount of one color, and they may use their underglazes on several
different clay bodies. A small jar of underglaze is very cheap, it comes in
almost unlimited colors, and it works on all clay bodies.
Cindi
>
> Why use a relatively expensive commercial underglaze, when for far less
> money you can mix up slips colored with oxides or mason stains?
> Best wishes -
> - Vince
vince pitelka on fri 12 apr 02
> > Why use a relatively expensive commercial underglaze, when for far less
> > money you can mix up slips colored with oxides or mason stains?
>
> 1. Because you're at a school where you only have so long to complete X
> number of projects that meet Y number of criteria, and mixing stuff slows
> you down
Michelle -
Not an adequate reason. It is very simple to mix up slips, and you can save
a great deal of money. The materials for the slip are cheap.
> 2. Because you don't have all the ingredients and may never have them
They are easy to get from any ceramic supplier, and as I said, they are
cheap, except for some of the coloring oxides and mason stains, and still
the total cost will be far less than commercial underglazes.
> 3. Because you don't know what you're doing when you try to mix up all
this
> stuff that is foreign to beginners in the art of ceramics
So find out.
> 4. Because you have NO idea what kind of result you're going to get
without
> testing first and our society has not been cultured on patience or
anything
> like it
So do some tests. This all hinges on whether you are committed to exploring
new territory and saving the school some money.
> 5. Because commercial products at least come with a color chart and you
can
> say, "Oh, there, I like that one."
That's baloney and you know it. Do some tests and you will be able to
predict your results as much as with any commercial underglaze.
> 6. Because naively you think commercial products are going to come out
just
> like the little ol' color chart (that the printer's color filter printed
out
> all wrong!)
You already said it. It's an illusion.
> 7. Because you've never done it and truth be told, you're kind of scared
> you'll make a mistake (like you'd die from an underglaze mistake)
It is really a simple matter. Pardon the self-promotion, but buy my book.
> 8. Because you are lazier than egg whites and won't stand up alone
without
> a beating, never mind take initiative
Okay, I can understand that it is a LOT of work teaching K-12 classes. But
like most situations, it is what you make of it. Either you will make a
difference or you won't. There are a lot of ways to do that. One way is to
make the most of the available funds, even if it means a little more work
for you. Mel is a good example of that. Throughout his high school
teaching career, he went WAY beyond the call of duty, and he got a lot of
kids fired up about art along the way.
> 9. Because it's there
Hmmmm. I do not have an answer to that, other than that easy slip recipes
and cheap ingredients are there as well.
> Did I miss anything?
I don't think so. Did I?
Best wishes -
- Vince
Vince Pitelka
Appalachian Center for Crafts
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
Home - vpitelka@dtccom.net
615/597-5376
Work - wpitelka@tntech.edu
615/597-6801 ext. 111, fax 615/597-6803
http://www.craftcenter.tntech.edu/
Anne Wellings on sat 13 apr 02
I don't use commercial underglazes, I use slips that are colored with
traditional coloring oxides and I mix myself. But I cannot imagine testing,
mixing, and keeping on hand slips in the multitude of colors that
commercial underglazes come in.
For someone who wants to play with all those colors and doesn't need huge
amounts of any of them, commercial underglazes make perfect sense to me.
Once a person has established a direction in their work and has narrowed
down the colors they want to use, yes, it would make sense to get into some
testing and formulating in order to be able to mix up an adequate supply of
what they need.
Anne
Anne Wellings on sat 13 apr 02
An addition to my last comment:
I would not knock a professional clay artist who chose to continue using
commercial underglazes even after establishing a direction in their work.
For someone doing jewelry or small whimsical sculpture and wanting access
to lots of colors that could be stored easily, the small bottles of
commercial underglazes could be the way to go.
At the same time, I think it is great when people take the initiative to
test and formulate their own materials and that there are resources
available, such as Vince's book, to help them do so. It is good for people
to know what their options are, that it isn't beyond them to mix up their
own underglazes or slips in great colors.
Everyone has different work and a different approach, and what seems
wasteful or not feasible to one person may be the most efficient for
someone else at a given point in time.
Anne
Martin Howard on sun 14 apr 02
Like Anne Wellings, I use coloured slips under a clear glaze.
After a lot of testing I have long strings of test tiles which I had to look
at because they hung over the stove alcove in the pottery. I never consulted
them!
I thought they would be a wonderful record of the path I've gone along.
Alas no.
Now they will go in the next hole in the ground to be found sometime in the
future and named as giant necklaces for the huge people who used to roam
this area:-)
We do change our direction from time to time. I wanted lots of different
glazes. Now I just really want one really good clear glaze that works on
both once fired and twice fired ware.
Everything else will be done by stains and standard oxides added to the
white slip which matches my red clay.
Then I can lots of different coloured slip buckets and just one glaze
bucket.
Underglazes? Why?
Martin Howard
Webbs Cottage Pottery
Woolpits Road, Great Saling
BRAINTREE, Essex CM7 5DZ
01371 850 423
martin@webbscottage.co.uk
http://www.webbscottage.co.uk
Updated 3rd March 2002
Longtin, Jeff on mon 15 apr 02
Vince,
Just to weigh in with an opposite experience. I use commercial underglazes
and find them to be great! Open bottle, apply to greenware, done. No scales,
no stains just pure color! Their brushability is really incredible. Much
better than any mixture I could create. And the colors are stable to cone 6.
Back when I was a potter I did it the way you describe. I still have bags of
silica, feldspars, and oxides on hand as a result. I never had good luck
with any engobe recipes I found. Maybe I should have tested more but I never
acheived really deep opaque colors like the commercial stuff. Also, I had to
apply leatherhard or wetter. With commerical I apply bonehard. If needed I
can also apply bisque without a problem. Certainly not all commercial
underglazes work great at cone 6 but most do.
A few years ago I was commissioned to make this little ceramic figurine and
the customer wanted the end product to have numerous colors. Numerous SOLID
colors. I knew it would take too long to test all those colors so I just
went commercial. I ended up just making the pieces and not coloring them,
but I learned to appreciate the convenience of the commercial stuff.
Take Care
Jeff Longtin
-----Original Message-----
From: vince pitelka [mailto:vpitelka@DTCCOM.NET]
Sent: Friday, April 12, 2002 8:01 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: underglazes question
> > Why use a relatively expensive commercial underglaze, when for far less
> > money you can mix up slips colored with oxides or mason stains?
>
> 1. Because you're at a school where you only have so long to complete X
> number of projects that meet Y number of criteria, and mixing stuff slows
> you down
Michelle -
Not an adequate reason. It is very simple to mix up slips, and you can save
a great deal of money. The materials for the slip are cheap.
> 2. Because you don't have all the ingredients and may never have them
They are easy to get from any ceramic supplier, and as I said, they are
cheap, except for some of the coloring oxides and mason stains, and still
the total cost will be far less than commercial underglazes.
> 3. Because you don't know what you're doing when you try to mix up all
this
> stuff that is foreign to beginners in the art of ceramics
So find out.
> 4. Because you have NO idea what kind of result you're going to get
without
> testing first and our society has not been cultured on patience or
anything
> like it
So do some tests. This all hinges on whether you are committed to exploring
new territory and saving the school some money.
> 5. Because commercial products at least come with a color chart and you
can
> say, "Oh, there, I like that one."
That's baloney and you know it. Do some tests and you will be able to
predict your results as much as with any commercial underglaze.
> 6. Because naively you think commercial products are going to come out
just
> like the little ol' color chart (that the printer's color filter printed
out
> all wrong!)
You already said it. It's an illusion.
> 7. Because you've never done it and truth be told, you're kind of scared
> you'll make a mistake (like you'd die from an underglaze mistake)
It is really a simple matter. Pardon the self-promotion, but buy my book.
> 8. Because you are lazier than egg whites and won't stand up alone
without
> a beating, never mind take initiative
Okay, I can understand that it is a LOT of work teaching K-12 classes. But
like most situations, it is what you make of it. Either you will make a
difference or you won't. There are a lot of ways to do that. One way is to
make the most of the available funds, even if it means a little more work
for you. Mel is a good example of that. Throughout his high school
teaching career, he went WAY beyond the call of duty, and he got a lot of
kids fired up about art along the way.
> 9. Because it's there
Hmmmm. I do not have an answer to that, other than that easy slip recipes
and cheap ingredients are there as well.
> Did I miss anything?
I don't think so. Did I?
Best wishes -
- Vince
Vince Pitelka
Appalachian Center for Crafts
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
Home - vpitelka@dtccom.net
615/597-5376
Work - wpitelka@tntech.edu
615/597-6801 ext. 111, fax 615/597-6803
http://www.craftcenter.tntech.edu/
____________________________________________________________________________
__
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.
vince pitelka on mon 15 apr 02
> colors. I knew it would take too long to test all those colors so I just
> went commercial. I ended up just making the pieces and not coloring them,
> but I learned to appreciate the convenience of the commercial stuff.
Jeff -
I never indicated that I have anything against commercial underglazes.
There are MANY times when commercial underglazes are the only thing that
makes sense, and certainly well worth the price. My point was that in most
cases the professional high-fire potter is better off mixing slips and
engobes from raw materials, because it is so much cheaper.
Best wishes -
- Vince
Vince Pitelka
Appalachian Center for Crafts
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
Home - vpitelka@dtccom.net
615/597-5376
Work - wpitelka@tntech.edu
615/597-6801 ext. 111, fax 615/597-6803
http://www.craftcenter.tntech.edu/
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