Keba M Hitzeman on mon 21 jan 08
I've been experimenting with glaze combinations recently, and doing the
vinegar test (3 day soak in vinegar) to see if anything goes wonky with the
glaze.
One glaze combo failed miserably, and my question is: is it supposed to
craze with white lines? None of the other glazes crazed in the vinegar, so
I don't have anything to compare it to.
Thanks!
Keba
====================================
Keba Hitzeman
Dayton OH
Spanish - http://keba.hitzeman.com
Clay -
http://yellowroomarts.blogspot.com,
http://yellowroomarts.etsy.com
Coffee - coffee@enigma22.com
People sleep peaceably in their beds at night only because rough men stand
ready to do violence on their behalf.
George Orwell
Ron Roy on mon 28 jan 08
Hi Keba,
Vinegar leaves a white residue after the water gas evaporated - sounds like
your clay may not be vitrified and the vinegar is evaporating through the
craze lines.
How else did that glaze fail?
RR
>I've been experimenting with glaze combinations recently, and doing the
>vinegar test (3 day soak in vinegar) to see if anything goes wonky with the
>glaze.
>
>
>
>One glaze combo failed miserably, and my question is: is it supposed to
>craze with white lines? None of the other glazes crazed in the vinegar, so
>I don't have anything to compare it to.
>Thanks!
>Keba
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Taylor Hendrix on mon 28 jan 08
Keba,
It sounds like you believe the vinegar test to be a test specifically
for crazing. Is this the case, or am I misreading you?
I heard a ^6 glossy red glaze pinging on some fired raku clay the
other day, but I could never see the crazing. A few drops of dirty
rinse water from my day of glazing, once dry, revealed a nice, tight
network of craze lines. They showed up as lighter lines within the
powdery residue left when the rinse water evaporated.
I know there are better ways to test for crazing, but I don't believe
that the vinegar test is one of them.
Keep up the good work,
--
Taylor, in Rockport TX
http://wirerabbit.blogspot.com
http://wirerabbitpots.blogspot.com
http://www.flickr.com/photos/wirerabbit/
Keba M Hitzeman on mon 28 jan 08
Ron,
I am low firing (cone 04 bisque, cone 05 glaze), and wanted to be extra
careful about crazing with the combinations I am experimenting with. The
only other experience I had with crazing was a different glaze that "pinged"
when I rinsed the vessel with water. I did not try the vinegar test on that
glaze, since I already found out that there was a problem.
Other than that, the glaze color was beautiful - I now know just to use it
on decorative items.
Would it be unheard of for two glazes that craze when combined to NOT craze
when used seperately? I have other vinegar-tested items that have not
crazed that are glazed with the same two glazes, but not combined, if that
makes sense.
Keba
====================================
Keba Hitzeman
Dayton OH
Spanish - http://keba.hitzeman.com
Clay - http://yellowroomarts.blogspot.com, http://yellowroomarts.etsy.com
Coffee - coffee@enigma22.com
People sleep peaceably in their beds at night only because rough men stand
ready to do violence on their behalf.
George Orwell
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of Ron Roy
Sent: Monday, January 28, 2008 02:23
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: The color of crazing lines
Hi Keba,
Vinegar leaves a white residue after the water gas evaporated - sounds like
your clay may not be vitrified and the vinegar is evaporating through the
craze lines.
How else did that glaze fail?
RR
>I've been experimenting with glaze combinations recently, and doing the
>vinegar test (3 day soak in vinegar) to see if anything goes wonky with the
>glaze.
>
>
>
>One glaze combo failed miserably, and my question is: is it supposed to
>craze with white lines? None of the other glazes crazed in the vinegar, so
>I don't have anything to compare it to.
>Thanks!
>Keba
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
____________________________________________________________________________
__
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You may look at the archives for the list, post messages, change your
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Keba M Hitzeman on tue 29 jan 08
Well, it had been mentioned (from what I read in the archives) as one of the
ways to check for crazing/leaching/unstable glaze-clay combo, so I thought
I'd try it. Did I misread something?
On my caramel glaze that was pinging, I could not see the craze lines (like
your glossy red), but received several suggestions about using india ink to
check...and there it was. The glaze combo that crazed with the vinegar
never pinged.
The white crazing lines actually look pretty sweet (at least to me), and
since it's no longer functional, I may just douse the whole thing in
vinegar...hopefully it won't explode or anything!
And now I have another question...one of the archived post mentioned that
Ron & John's Mastering Cone 6 Glazes deals with suitability testing. Would
their information also work for low-fire (04-05)?
Keba
====================================
Keba Hitzeman
Dayton OH
Spanish - http://keba.hitzeman.com
Clay - http://yellowroomarts.blogspot.com, http://yellowroomarts.etsy.com
Coffee - coffee@enigma22.com
People sleep peaceably in their beds at night only because rough men stand
ready to do violence on their behalf.
George Orwell
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of Taylor Hendrix
Sent: Monday, January 28, 2008 19:25
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: The color of crazing lines
Keba,
It sounds like you believe the vinegar test to be a test specifically
for crazing. Is this the case, or am I misreading you?
I heard a ^6 glossy red glaze pinging on some fired raku clay the
other day, but I could never see the crazing. A few drops of dirty
rinse water from my day of glazing, once dry, revealed a nice, tight
network of craze lines. They showed up as lighter lines within the
powdery residue left when the rinse water evaporated.
I know there are better ways to test for crazing, but I don't believe
that the vinegar test is one of them.
Keep up the good work,
--
Taylor, in Rockport TX
http://wirerabbit.blogspot.com
http://wirerabbitpots.blogspot.com
http://www.flickr.com/photos/wirerabbit/
____________________________________________________________________________
__
Clayart members may send postings to: clayart@lsv.ceramics.org
You may look at the archives for the list, post messages, change your
subscription settings or unsubscribe/leave the list here:
http://www.acers.org/cic/clayart/
Moderator of the list is Mel Jacobson who may be reached at
melpots2@visi.com
Ron Roy on wed 30 jan 08
Hi Keba,
Vinegar is one way of testing a glaze to see how durable it is in the
presence of acidic food. It only shows grossly unstable glazes by the way.
A lab test is the correct way to find out exactly how much a glaze will
leach.
Some glazes come out of the kiln crazed - they will sometime "ping" simply
because they are still crazing. Some glazes can take longer to craze -
sometime years - depending on the expansion/contraction of the clay and
glaze. The longer it takes to craze the easier it will be to fix.
If you care to send me the recipe of your glaze I may be able to fix it.
Just send to ronroy@ca.inter.net
If you mix two crazing glazes the result will graze. If one does not and
the other does - it may or may not craze depending on the resulting
expansion/contraction. If you mix two glazes that don't craze the result
will not craze.
RR
>Ron,
>
>I am low firing (cone 04 bisque, cone 05 glaze), and wanted to be extra
>careful about crazing with the combinations I am experimenting with. The
>only other experience I had with crazing was a different glaze that "pinged"
>when I rinsed the vessel with water. I did not try the vinegar test on that
>glaze, since I already found out that there was a problem.
>
>Other than that, the glaze color was beautiful - I now know just to use it
>on decorative items.
>
>Would it be unheard of for two glazes that craze when combined to NOT craze
>when used seperately? I have other vinegar-tested items that have not
>crazed that are glazed with the same two glazes, but not combined, if that
>makes sense.
>
>Keba
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
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