How dose one "fill in" the cracks on a crackle glaze?

I searched the site for answers, but not even sure I pose the question
right.
I accidently was send a very nice white crackle glaze from Laguna Clay,
Something I probably would never consider, but I got it just the same,
and it's very nice. What I might like to do with it is the technique
that I believe is rubbing something over the glazed piece, after it has
been glaze fired to get that black & white pronounced crackle look.

I heard that once upon a time people just rubbed black liquid pen ink
over it, and then just wiped off.

I'm sure somebody out there will know the answers.
Thanks
Sa

i've heard of this too, but never wanted to do any myself. i think tea
is used sometimes. as with an old tea cup. the cracks start to show
up in time.

see ya

steve



On Nov 18, 5:29*pm, wrote:
I searched the site for answers, but not even sure I pose the question
right.
I accidently was send a very nice white crackle glaze from Laguna Clay,
Something I probably would never consider, but I got it just the same,
and it's very nice. What I might like to do with it is the technique
that I believe is rubbing something over the glazed piece, after it has
been glaze fired to get that black & white pronounced crackle look.

I heard that once upon a time people just rubbed black liquid pen ink
over it, and then just wiped off.

I'm sure somebody out there will know the answers.
Thanks
Sa

The usual way is to rub in Indian ink (from any local stationary shop). The work
can then be heated in and oven to 200deg C to seal the ink in...This does not
make it waterproof. For waterproof, use a low temp glaze with 8% black
stain and fire the piece in your next bisque firing.
Hope this helps.
Mike.


wrote:
I searched the site for answers, but not even sure I pose the question
right.
I accidently was send a very nice white crackle glaze from Laguna Clay,
Something I probably would never consider, but I got it just the same,
and it's very nice. What I might like to do with it is the technique
that I believe is rubbing something over the glazed piece, after it has
been glaze fired to get that black & white pronounced crackle look.

I heard that once upon a time people just rubbed black liquid pen ink
over it, and then just wiped off.

I'm sure somebody out there will know the answers.
Thanks
Sa

On 18 Nov 2006 17:29:19 -0800, wrote:

I searched the site for answers, but not even sure I pose the question
right.
I accidently was send a very nice white crackle glaze from Laguna Clay,
Something I probably would never consider, but I got it just the same,
and it's very nice. What I might like to do with it is the technique
that I believe is rubbing something over the glazed piece, after it has
been glaze fired to get that black & white pronounced crackle look.

I heard that once upon a time people just rubbed black liquid pen ink
over it, and then just wiped off.

I'm sure somebody out there will know the answers.
Thanks
Sa


I've also heard India ink recommended. When I wanted to try this
technique, I didn't have any India ink so I used what I had, which
was ink for a stamp pad. Seemed to work OK. Also tried black
artist's acrylic paint, suitably thinned with water, and it worked
also. Indelible flet-tip ("Sharpie", etc) works as well.

I was trying this on Egyptian paste beads, so you may get different
results on stoneware, etc. But I suspect that just about anything
that is dark and relatively permanent will work.

Best regards,


Bob Masta
dqatechATdaqartaDOTcom

D A Q A R T A
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Home of DaqGen, the FREEWARE signal generator

There's a technique I've read about, but never tried, that is a more
permanent way of retaining the crackle lines but still ending up with a
watertight glaze surface. It involves firing the object to a temperature
lower than the final maturation point of the clay body, at which point there
is a mismatch in the coefficient of expansion of the clay versus the glaze,
causing a crackle pattern. Oxide is rubbed into the cracks, then the piece
is refired to a higher temperature. At that point, the COEs match, so the
glaze reflows but doesn't crack - but the oxide is still there, as color
only. Needless to say, there's probably a lot of experimentation required to
get this to actually work...

Andrew Werby
www.unitedartworks.com


----- Original Message -----
From:
Newsgroups: rec.crafts.pottery
Sent: Saturday, November 18, 2006 5:29 PM
Subject: How dose one "fill in" the cracks on a crackle glaze?


I searched the site for answers, but not even sure I pose the question
right.
I accidently was send a very nice white crackle glaze from Laguna Clay,
Something I probably would never consider, but I got it just the same,
and it's very nice. What I might like to do with it is the technique
that I believe is rubbing something over the glazed piece, after it has
been glaze fired to get that black & white pronounced crackle look.

I heard that once upon a time people just rubbed black liquid pen ink
over it, and then just wiped off.

I'm sure somebody out there will know the answers.
Thanks
Sa

On Sun, 19 Nov 2006 13:58:34 -0800, "Andrew Werby"
wrote:

There's a technique I've read about, but never tried, that is a more
permanent way of retaining the crackle lines but still ending up with a
watertight glaze surface. It involves firing the object to a temperature
lower than the final maturation point of the clay body, at which point there
is a mismatch in the coefficient of expansion of the clay versus the glaze,
causing a crackle pattern. Oxide is rubbed into the cracks, then the piece
is refired to a higher temperature. At that point, the COEs match, so the
glaze reflows but doesn't crack - but the oxide is still there, as color
only. Needless to say, there's probably a lot of experimentation required to
get this to actually work...

Andrew Werby
www.unitedartworks.com


I'd love to find an all-ceramic method like you mention,
but I don't understand the theroy behind this. The cracks
appear on cooling, so what prevents new cracks from
forming after the final firing? I think you'd get the effect
you wanted on the cracks you filled with oxide, but then
there would always be other unfilled cracks as well, from
the final cool-down.

Or am I missing something?

Best regards,


Bob Masta
dqatechATdaqartaDOTcom

D A Q A R T A
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Home of DaqGen, the FREEWARE signal generator

"Bob Masta" wrote in message
...
On Sun, 19 Nov 2006 13:58:34 -0800, "Andrew Werby"
wrote:

There's a technique I've read about, but never tried, that is a more
permanent way of retaining the crackle lines but still ending up with a
watertight glaze surface. It involves firing the object to a temperature
lower than the final maturation point of the clay body, at which point
there
is a mismatch in the coefficient of expansion of the clay versus the
glaze,
causing a crackle pattern. Oxide is rubbed into the cracks, then the piece
is refired to a higher temperature. At that point, the COEs match, so the
glaze reflows but doesn't crack - but the oxide is still there, as color
only. Needless to say, there's probably a lot of experimentation required
to
get this to actually work...

Andrew Werby
www.unitedartworks.com


I'd love to find an all-ceramic method like you mention,
but I don't understand the theroy behind this. The cracks
appear on cooling, so what prevents new cracks from
forming after the final firing? I think you'd get the effect
you wanted on the cracks you filled with oxide, but then
there would always be other unfilled cracks as well, from
the final cool-down.

Or am I missing something?

Best regards,


Bob Masta
dqatechATdaqartaDOTcom

D A Q A R T A
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Home of DaqGen, the FREEWARE signal generator

So if the pot has been fired and done all the shrinking it is going to do,
and the glass (glaze) remelts and spreads out.... it seems to me that now
there is not an issue of fit because there is no shrinkage of the body....
but then I'm not clear on what is going on in crazing. For instance, why
does the crazing happen after the pot has already cooled down?

[Look guys, I never said I'd made this work; I'm just reporting about an
approach I'd heard about. The idea is that a glaze that doesn't fit (and
cracks) when underfired, due to mismatched coefficients of expansion, does
fit (and doesn't crack) when it reaches maturity. I've never seen it happen,
and it could be a potters' legend, for all I know. Is there anything about
it on Clayart?]

Andrew




"DKat" wrote in message
...

"Bob Masta" wrote in message
...
On Sun, 19 Nov 2006 13:58:34 -0800, "Andrew Werby"
wrote:

There's a technique I've read about, but never tried, that is a more
permanent way of retaining the crackle lines but still ending up with a
watertight glaze surface. It involves firing the object to a temperature
lower than the final maturation point of the clay body, at which point
there
is a mismatch in the coefficient of expansion of the clay versus the
glaze,
causing a crackle pattern. Oxide is rubbed into the cracks, then the
piece
is refired to a higher temperature. At that point, the COEs match, so the
glaze reflows but doesn't crack - but the oxide is still there, as color
only. Needless to say, there's probably a lot of experimentation required
to
get this to actually work...

Andrew Werby
www.unitedartworks.com


I'd love to find an all-ceramic method like you mention,
but I don't understand the theroy behind this. The cracks
appear on cooling, so what prevents new cracks from
forming after the final firing? I think you'd get the effect
you wanted on the cracks you filled with oxide, but then
there would always be other unfilled cracks as well, from
the final cool-down.

Or am I missing something?

Best regards,


Bob Masta
dqatechATdaqartaDOTcom

D A Q A R T A
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Home of DaqGen, the FREEWARE signal generator

So if the pot has been fired and done all the shrinking it is going to do,
and the glass (glaze) remelts and spreads out.... it seems to me that now
there is not an issue of fit because there is no shrinkage of the body....
but then I'm not clear on what is going on in crazing. For instance, why
does the crazing happen after the pot has already cooled down?

Andrew Werby wrote:
[Look guys, I never said I'd made this work; I'm just reporting about an
approach I'd heard about. The idea is that a glaze that doesn't fit (and
cracks) when underfired, due to mismatched coefficients of expansion, does
fit (and doesn't crack) when it reaches maturity. I've never seen it happen,
and it could be a potters' legend, for all I know. Is there anything about
it on Clayart?]

Andrew




"DKat" wrote in message
...
"Bob Masta" wrote in message
...
On Sun, 19 Nov 2006 13:58:34 -0800, "Andrew Werby"
wrote:

There's a technique I've read about, but never tried, that is a more
permanent way of retaining the crackle lines but still ending up with a
watertight glaze surface. It involves firing the object to a temperature
lower than the final maturation point of the clay body, at which point
there
is a mismatch in the coefficient of expansion of the clay versus the
glaze,
causing a crackle pattern. Oxide is rubbed into the cracks, then the
piece
is refired to a higher temperature. At that point, the COEs match, so the
glaze reflows but doesn't crack - but the oxide is still there, as color
only. Needless to say, there's probably a lot of experimentation required
to
get this to actually work...

Andrew Werby
www.unitedartworks.com

I'd love to find an all-ceramic method like you mention,
but I don't understand the theroy behind this. The cracks
appear on cooling, so what prevents new cracks from
forming after the final firing? I think you'd get the effect
you wanted on the cracks you filled with oxide, but then
there would always be other unfilled cracks as well, from
the final cool-down.

Or am I missing something?

Best regards,


Bob Masta
dqatechATdaqartaDOTcom

D A Q A R T A
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Home of DaqGen, the FREEWARE signal generator
So if the pot has been fired and done all the shrinking it is going to do,
and the glass (glaze) remelts and spreads out.... it seems to me that now
there is not an issue of fit because there is no shrinkage of the body....
but then I'm not clear on what is going on in crazing. For instance, why
does the crazing happen after the pot has already cooled down?




There be a man in this area caaleed Rupert Andrews and he makes the most
incredible crackle glazed pots.... Don't know how he does it but it
seems to entail firing below matureing temp and then using another glaze
and going all the way....
Hope this helps
look him up on Google...
Hugs
Eddie

On Tue, 21 Nov 2006 16:07:08 +0000, Eddie Daughton
wrote:

There be a man in this area caaleed Rupert Andrews and he makes the most
incredible crackle glazed pots.... Don't know how he does it but it
seems to entail firing below matureing temp and then using another glaze
and going all the way....
Hope this helps
look him up on Google...
Hugs
Eddie

Wow! I especially liked this pot:
http://www.themousehole.com/images/andrews01.jpg

This concept of being able to refire after filling the craze lines
with oxide (if that is in fact what Rupert Andrews is doing)
seems to call for some serious experimenting.
First of all, we should note that this has nothing to do with
the shrinkage that the body goes through at maturation, as such
Crazing happens on cool-down due to a difference in
coefficients of expansion between body and glaze.
However, the question is whether maturation causes a change
in body COE. I suggested this on Clayart a couple of years ago,
based on some crazing issues I had that were cured by moving
up to a higher cone, and Ron Roy pointed out that the more
likely explanation was that the changes I had made to the glaze
to get it to not run off the pot were also changing the COE. I
never followed up on that at the time... maybe now is the time!

The other thing is that if we fire at a low temperature and get
crazing, then fill in the lines with oxides and refire to a higher
temperature, that means the original glaze had to be able to
melt at the low temp, so that it could craze on the
initial cooling. Then the *same glaze* has to stay on the pot
when fired to a higher temp that matures the body. Seems
like a delicate balancing act. Actually, if there is any merit to
the idea of the body COE changing so that the second firing
doesn't craze, then maybe the oxide-filled craze lines will
run a bit... could be a nice effect on its own.

What I have heard of is simply using a normal crazing glaze,
filling the lines with oxide, and refiring the same way. Of
course, on the second firing you will get additional craze lines,
but they won't have the oxide accent.

How about instead of filling with a pure oxide, we find some
mix that melts easily at a much lower temperature than the
original glaze? That way the colors could melt into the pot before
the original glaze softened enough to move, and hence to re-craze
on cool-down. I suspect that this may be tricky, since I think that
it will take very little temperature to soften the original glaze
enough to re-craze.

Just some thoughts...




Bob Masta
dqatechATdaqartaDOTcom

D A Q A R T A
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Home of DaqGen, the FREEWARE signal generator