Kristin on mon 27 jan 03
Hello, helpful folks -
Two quick questions, the first of which I think I know
the answer:
1. One of my glazes didn't adhere well to my
^04-bisqued pieces, 2 different clay bodies. When it
tried to crack and fall off the day after dipping, I
just went back and smoothed it back down. Where I only
half-arsed this "smoothing down," it did fall off in
little spots during the firing. The glaze was really
thick, which I previously thought just meant I should
only hold the pieces in the bucket for a shorter
period of time. However, my guess is this caused this
problem. Am I right -- add more water, and I'll be
fine? (I've seen other folks suffer this misfortune.
But those times were blamed on dust on the pot prior
to dipping, which mine did not have.)
2. Another glaze suffered the
bubbles-that-will-turn-into-pinholes-if-you-don't-smooth-them-down-before-firing
syndrome. I've always been in the habit to go back and
fix this after the glaze dries, no big deal. But now
that I'm going through hundreds of pounds of clay
pretty regularly, this seems a pretty silly,
time-consuming step. Is there a way to make these tiny
bubbles not show up when dipping in the first place?
The particular glaze doing this is RR/JH's Bone, if
that is a factor.
As always, thanks for your help. I can't wait for the
day _I_ can actually answer someone's query, instead
of always asking.
- Kristin, in frigid but glorious central Illinois.
Planning a roadrip to my first-ever workshop next
weekend, given by a wonderful potter I happened to
meet at a festival for our other shared passion. Life
is good.
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claybair on mon 27 jan 03
Hi Kristin,
Yes I think your glaze is too thick. You will get other
postings with tips on dealing with it or just search archives.
My main reason for posting is that I have noticed 2 other
causes.
1. Adding too much air when stirring glaze.
Try to stir your glaze gently & not foam the top like a latte as the bubbles
will show up on the glaze surface. If using some mechanical means (paint
mixer on a drill, hand blender etc) use a slow speed & keep the mixer near
the bottom of the bucket so you do not incorporate air into the glaze.
2. Air bubbles on pots that have undercuts.
A lot of my works is heavily carved. I have resorted to brushing thin washes
of glaze which works for my current style. Now I haven't tried this but it
makes sense to me! You might try a rather thin initial glaze dip. The glaze
will have to work less hard to get around the undercut. If it fills in the
undercut the next dipping in the thicker glaze may not cause a bubble. If
you try this and it works do let me know.
A few months ago when I glazed a pot too thickly I tried something new.
Instead of washing it all off I gently brushed water onto the cracks until
they blended and were no longer visible. Now on a pot that would have
crazed horribly there were only 2 spots that actually crazed and that was
because I didn't brush those areas until the crack disappeared. If you get
too vigorous and brush down to the bisque fill it in. It was a lazy way to
deal with it but it actually worked.
However I did have to sell it as a second and should have just washed it
off.
Good luck,
Gayle Bair
Bainbridge Island, WA
http://claybair.com
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG]On Behalf Of Kristin
Sent: Monday, January 27, 2003 8:07 AM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Elementary glaze questions
Hello, helpful folks -
Two quick questions, the first of which I think I know
the answer:
1. One of my glazes didn't adhere well to my
^04-bisqued pieces, 2 different clay bodies. When it
tried to crack and fall off the day after dipping, I
just went back and smoothed it back down. Where I only
half-arsed this "smoothing down," it did fall off in
little spots during the firing. The glaze was really
thick, which I previously thought just meant I should
only hold the pieces in the bucket for a shorter
period of time. However, my guess is this caused this
problem. Am I right -- add more water, and I'll be
fine? (I've seen other folks suffer this misfortune.
But those times were blamed on dust on the pot prior
to dipping, which mine did not have.)
2. Another glaze suffered the
bubbles-that-will-turn-into-pinholes-if-you-don't-smooth-them-down-before-fi
ring
syndrome. I've always been in the habit to go back and
fix this after the glaze dries, no big deal. But now
that I'm going through hundreds of pounds of clay
pretty regularly, this seems a pretty silly,
time-consuming step. Is there a way to make these tiny
bubbles not show up when dipping in the first place?
The particular glaze doing this is RR/JH's Bone, if
that is a factor.
As always, thanks for your help. I can't wait for the
day _I_ can actually answer someone's query, instead
of always asking.
- Kristin, in frigid but glorious central Illinois.
Planning a roadrip to my first-ever workshop next
weekend, given by a wonderful potter I happened to
meet at a festival for our other shared passion. Life
is good.
__________________________________________________
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Yahoo! Mail Plus - Powerful. Affordable. Sign up now.
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__
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Moderator of the list is Mel Jacobson who may be reached at
melpots@pclink.com.
Snail Scott on mon 27 jan 03
At 08:06 AM 1/27/03 -0800, you wrote:
>1. One of my glazes didn't adhere well to my
>^04-bisqued pieces...The glaze was really
>thick, which I previously thought just meant I should
>only hold the pieces in the bucket for a shorter
>period of time. However, my guess is this caused this
>problem. Am I right -- add more water, and I'll be
>fine? (I've seen other folks suffer this misfortune.
>But those times were blamed on dust on the pot prior
>to dipping, which mine did not have.)
Nope, your symptoms sound like 'too thick'.
Water it down; you'll be fine. (Cracking and
falling off is the key symptom. Dusty bisque
usually doesn't cause cracking; it mainly just
'peels back' during firing.)
>2. Another glaze suffered the
>bubbles-that-will-turn-into-pinholes-if-you-don't-smooth-them-down-before-f
iring
>syndrome.
I find that dampening the bisque helps with
this. (You'll need to make sure it goes on
thick enough, though, since the damp bisque
will absorb less glaze in the same length
of dip.)
-Snail
Lily Krakowski on tue 28 jan 03
Something is wrong here. Either your glazes are weird--unlikely, really as
I assume you got the recipes from someone who tested them--or your
application is off.
It sounds to me like your bisque is too dry and sucking up the glaze water
too fast; or that you are applying your glaze too thickly; or that it needs
some bentonite or similar. Or, contrary wise, if you glaze the inside first
you are not allowing the bisque to dry enough for the outside glaze to
adhere.
Do me a favor: Take some glaze --about a quart-- and put it on one "side"of
a big piece of bisque. Then thin the glaze (about 1/4 c. water) and put it
on another side. The thin again and test on a third side.
(I know round objects have no sides....but give me a break here.) See if
any of that works.
As to all this rubbing and patting of once-applied glazes. I say forget it.
Caresses help smooth over human relationships. Sometimes. I have never seen
them smooth over glazes properly. I believe in rinsing and drying and
starting over.
Kristin writes:
> Hello, helpful folks -
>
> Two quick questions, the first of which I think I know
> the answer:
>
> 1. One of my glazes didn't adhere well to my
> ^04-bisqued pieces, 2 different clay bodies. When it
> tried to crack and fall off the day after dipping, I
> just went back and smoothed it back down. Where I only
> half-arsed this "smoothing down," it did fall off in
> little spots during the firing. The glaze was really
> thick, which I previously thought just meant I should
> only hold the pieces in the bucket for a shorter
> period of time. However, my guess is this caused this
> problem. Am I right -- add more water, and I'll be
> fine? (I've seen other folks suffer this misfortune.
> But those times were blamed on dust on the pot prior
> to dipping, which mine did not have.)
>
> 2. Another glaze suffered the
> bubbles-that-will-turn-into-pinholes-if-you-don't-smooth-them-down-before-firing
> syndrome. I've always been in the habit to go back and
> fix this after the glaze dries, no big deal. But now
> that I'm going through hundreds of pounds of clay
> pretty regularly, this seems a pretty silly,
> time-consuming step. Is there a way to make these tiny
> bubbles not show up when dipping in the first place?
> The particular glaze doing this is RR/JH's Bone, if
> that is a factor.
>
> As always, thanks for your help. I can't wait for the
> day _I_ can actually answer someone's query, instead
> of always asking.
>
> - Kristin, in frigid but glorious central Illinois.
> Planning a roadrip to my first-ever workshop next
> weekend, given by a wonderful potter I happened to
> meet at a festival for our other shared passion. Life
> is good.
>
> __________________________________________________
> Do you Yahoo!?
> Yahoo! Mail Plus - Powerful. Affordable. Sign up now.
> http://mailplus.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.
Lili Krakowski
P.O. Box #1
Constableville, N.Y.
(315) 942-5916/ 397-2389
Be of good courage....
Ababi on tue 28 jan 03
Recently new comers are asking for medicine without giving us the recipe that make
them sick!
It might come from Ron and Johns request to keep their book out of the "clayart
game".
John and Ron are right as they worked a lot and spent a lot. Yet the "common" potter
must give a recipe, if not to all of us at least to his favorite glaze guru or glaze addict.
One of the times I was chosen to analyze a secret recipe that the sender was not
willing to share with the least I found out it had been one of these recipes we all knew.
By knowing from what the cake was made: I might tell you why you are sick!
Ababi Sharon
Glaze addict
Kibbutz Shoval Israel
ababisha@shoval.org.il
http://members4.clubphoto.com/ababi306910/
http://www.milkywayceramics.com/cgallery/asharon.htm
and also
http://www.israel-ceramics.org/membersGallery/personalpage.asp?MID=507
---------- Original Message ----------
>Something is wrong here. Either your glazes are weird--unlikely, really as
>I assume you got the recipes from someone who tested them--or your
>application is off.
.
Kristin on tue 28 jan 03
True, Ababi, true.
Although I of course cannot spill my guts on the
actual recipes I used, I am in addition guilty of not
giving enough detail, in general, to any of my
questions. I can sort of expand:
The glaze that didn't stick to the bisqueware was
RR/JH's Cranberry. But in test runs, I didn't have
this problem at all. So I assumed it had to do with
the specific batch or with my ware prep, etc. Most
people who have written back agree it was probably
just the thickness of it (it was a very, very thick
mix I knew I shouldn't be using, just one of those
stupid crunch-time decisions . . .). It did turn out
fine, where it stuck.
The glaze with bubbles all over it was RR/JH's Bone.
After thinking about it, reading folks' suggestions, I
figure it was a super-bubbly batch because this one
was actually too thin. So it more easily splashed
around, creating bubbles, when I stirred it.
Simple, simple problems, both of them. I just hadn't
experienced the first one before (someone else was
always adding water to glazes before I got to them),
and had always learned to live with the second one
when it happened. Trying to be more efficient with my
time in the studio, though, so it just won't do from
here on out.
I'm going to go try this the right way next time . . .
Thanks again - Kristin
--- Ababi wrote:
> Recently new comers are asking for medicine without
> giving us the recipe that make
> them sick!
> It might come from Ron and Johns request to keep
> their book out of the "clayart
> game".
> John and Ron are right as they worked a lot and
> spent a lot. Yet the "common" potter
> must give a recipe, if not to all of us at least to
> his favorite glaze guru or glaze addict.
> One of the times I was chosen to analyze a secret
> recipe that the sender was not
> willing to share with the least I found out it had
> been one of these recipes we all knew.
>
> By knowing from what the cake was made: I might tell
> you why you are sick!
> Ababi Sharon
> Glaze addict
> Kibbutz Shoval Israel
> ababisha@shoval.org.il
> http://members4.clubphoto.com/ababi306910/
> http://www.milkywayceramics.com/cgallery/asharon.htm
> and also
>
http://www.israel-ceramics.org/membersGallery/personalpage.asp?MID=507
> ---------- Original Message ----------
>
> >Something is wrong here. Either your glazes are
> weird--unlikely, really as
> >I assume you got the recipes from someone who
> tested them--or your
> >application is off.
__________________________________________________
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Ron Roy on wed 29 jan 03
Hi Krisin,
Yes - add water till the application is right - thick glazes often crack up
as they dry. Another way to get glazes to crawl is to fire them while they
are still wet. Some glazes are more likely to crawl as well - subbing ball
clay for kaolins (use calculation soft ware to make sure Al2O3 and SiO2 are
the same) or adding a binder are ways to make the surface tougher and
prevent the kind of cracking that leads to crawling.
The bubbles you find on the surface of glaze are not the cause of pin holes
- well designed glazes will smooth out at the end of the firing. Pin holes
are the result of gases escaping from glaze at the end of the firings -
bubbles that have not had a chance to heal over. The gases can come from
the glaze itself or the clay underneath - fire bisque slow and clean to
eliminate body produced gases. If the pin holes are still a problem soak
longer, or make you glaze flux a bit more - usually removing clay is the
answer. Slow heating towards the end - soaking and even slow cooling a bit
are all good ways to help give the bubbles time to smooth over.
Thick glazes are more likely to pin hole - thicker glaze needs to have more
time for the gases to escape at the end.
RR
>Two quick questions, the first of which I think I know
>the answer:
>
>1. One of my glazes didn't adhere well to my
>^04-bisqued pieces, 2 different clay bodies. When it
>tried to crack and fall off the day after dipping, I
>just went back and smoothed it back down. Where I only
>half-arsed this "smoothing down," it did fall off in
>little spots during the firing. The glaze was really
>thick, which I previously thought just meant I should
>only hold the pieces in the bucket for a shorter
>period of time. However, my guess is this caused this
>problem. Am I right -- add more water, and I'll be
>fine? (I've seen other folks suffer this misfortune.
>But those times were blamed on dust on the pot prior
>to dipping, which mine did not have.)
>
>2. Another glaze suffered the
>bubbles-that-will-turn-into-pinholes-if-you-don't-smooth-them-down-before-f
>iring
>syndrome. I've always been in the habit to go back and
>fix this after the glaze dries, no big deal. But now
>that I'm going through hundreds of pounds of clay
>pretty regularly, this seems a pretty silly,
>time-consuming step. Is there a way to make these tiny
>bubbles not show up when dipping in the first place?
>The particular glaze doing this is RR/JH's Bone, if
>that is a factor.
>
>As always, thanks for your help. I can't wait for the
>day _I_ can actually answer someone's query, instead
>of always asking.
>
>- Kristin, in frigid but glorious central Illinois.
>Planning a roadrip to my first-ever workshop next
>weekend, given by a wonderful potter I happened to
>meet at a festival for our other shared passion. Life
>is good.
>
>__________________________________________________
>Do you Yahoo!?
>Yahoo! Mail Plus - Powerful. Affordable. Sign up now.
>http://mailplus.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.
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
Ababi on wed 29 jan 03
Hello Kristin
I have learnt a lot from R&J's book but I suit them to my needs:
The "book" is right behind me but I will not check these recipes because there are a
few elementary things:
The writers offer us to bisque to ^04. I did it once and found it was bad for me.
European claybodies? may be but I use two of Laguna. I bisque at 1000C as this is
the bisque temperature of paperclay
When I make a glaze to 100 grams of glaze: If it is has low clay I add 80-90 grams ,
milliliter - CC - water.
If it has 15-20 clay 100CC water
30 clay 120CC water
If I added too much I live the jar slightly opened for a few days
Except the high magnesia glaze that must be very thick, I might add 150CC to be able
to mix them and than let the, be thicker.
Ababi Sharon
Glaze addict
Kibbutz Shoval Israel
ababisha@shoval.org.il
http://members4.clubphoto.com/ababi306910/
---------- Original Message ----------
>True, Ababi, true.
>Although I of course cannot spill my guts on the
>actual recipes I used, I am in addition guilty of not
>giving enough detail, in general, to any of my
>questions. I can sort of expand:
>The glaze that didn't stick to the bisqueware was
>RR/JH's Cranberry. But in test runs, I didn't have
>this problem at all. So I assumed it had to do with
>the specific batch or with my ware prep, etc. Most
>people who have written back agree it was probably
>just the thickness of it (it was a very, very thick
>mix I knew I shouldn't be using, just one of those
>stupid crunch-time decisions . . .). It did turn out
>fine, where it stuck.
>The glaze with bubbles all over it was RR/JH's Bone.
>After thinking about it, reading folks' suggestions, I
>figure it was a super-bubbly batch because this one
>was actually too thin. So it more easily splashed
>around, creating bubbles, when I stirred it.
>Simple, simple problems, both of them. I just hadn't
>experienced the first one before (someone else was
>always adding water to glazes before I got to them),
>and had always learned to live with the second one
>when it happened. Trying to be more efficient with my
>time in the studio, though, so it just won't do from
>here on out.
>I'm going to go try this the right way next time . . .
>Thanks again - Kristin
>--- Ababi wrote:
>> Recently new comers are asking for medicine without
>> giving us the recipe that make
>> them sick!
>> It might come from Ron and Johns request to keep
>> their book out of the "clayart
>> game".
>> John and Ron are right as they worked a lot and
>> spent a lot. Yet the "common" potter
>> must give a recipe, if not to all of us at least to
>> his favorite glaze guru or glaze addict.
>> One of the times I was chosen to analyze a secret
>> recipe that the sender was not
>> willing to share with the least I found out it had
>> been one of these recipes we all knew.
>>
>> By knowing from what the cake was made: I might tell
>> you why you are sick!
>> Ababi Sharon
>> Glaze addict
>> Kibbutz Shoval Israel
>> ababisha@shoval.org.il
>> http://members4.clubphoto.com/ababi306910/
>> http://www.milkywayceramics.com/cgallery/asharon.htm
>> and also
>>
>http://www.israel-ceramics.org/membersGallery/personalpage.asp?MID=507
>> ---------- Original Message ----------
>>
>> >Something is wrong here. Either your glazes are
>> weird--unlikely, really as
>> >I assume you got the recipes from someone who
>> tested them--or your
>> >application is off.
>
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