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delayed crazing?

updated sat 5 apr 08

 

Lili Krakowski on wed 9 jan 08


I know that crazing comes from a poor fit between the glaze and the body.
And that in some cases the glaze and body just do not melt together enough
at their "interface." And that a body that absorbs water--which a great
many will do over time--will eventually pry the glaze apart and craze it.

BUT this business of the dishwasher and micro raises some questions:

Could the materials in the dishwasher "soap" weaken the glaze in some way so
that it will craze? Can it make the glaze leach and will leaching lead to
crazing?

Were these glazes that crazed on those bodies tested with the good old
fashioned boiling test?

What was the absorption on those bodies?

Has this happened with fully vitrified porcelain?






Lili Krakowski
Be of good courage

Lois Ruben Aronow on wed 9 jan 08


In my case, I did do a boil test, but honestly, I did not do one every day
for 6 years. That's how my in-laws use their mugs. I think they are the
only 2 mugs they use, and they boil water in them in the microwave several
times a day to make their tea.

I have run my stuff through the dishwasher on a regular (oftentimes daily)
basis for years with no problem, as have my friends. This "test" works
fine.

I still consider my work to be functional. It is my feeling that the way my
in-laws use the work is unusual - above and beyond the way ANYONE would use
ANY mug. I'm not making restaurant grade dinnerware, which is made for
heavy duty use.

I liken it to wearing your good lingerie on a daily basis instead of your
everyday stuff. I have no analogy for the dudes.

Your mileage may vary.

...lo

**********
Lois Aronow Porcelain

Brooklyn, NY


www.loisaronow.com





> -----Original Message-----
> From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of
> Lili Krakowski
> Sent: Wednesday, January 09, 2008 11:52 AM
> To: CLAYART@LSV.CERAMICS.ORG
> Subject: Delayed crazing?
>
> I know that crazing comes from a poor fit between the glaze
> and the body.
> And that in some cases the glaze and body just do not melt
> together enough at their "interface." And that a body that
> absorbs water--which a great many will do over time--will
> eventually pry the glaze apart and craze it.
>
> BUT this business of the dishwasher and micro raises some questions:
>
> Could the materials in the dishwasher "soap" weaken the glaze
> in some way so that it will craze? Can it make the glaze
> leach and will leaching lead to crazing?
>
> Were these glazes that crazed on those bodies tested with the
> good old fashioned boiling test?
>
> What was the absorption on those bodies?
>
> Has this happened with fully vitrified porcelain?
>
>
>
>
>
>
> Lili Krakowski
> Be of good courage
>
> ______________________________________________________________
> ________________
> Clayart members may send postings to: clayart@lsv.ceramics.org
>
> You may look at the archives for the list, post messages, or
> change your subscription settings here:
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> Moderator of the list is Mel Jacobson who may be reached at
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Ron Roy on thu 10 jan 08


An interesting question from Lili,

Glazes that are short of alumina are more subject to degradation from
alkalies (soap) - particularly in dish washers. The interesting part is -
if that was so - the soap attacking the glazes - could that alter the
expansion of a glaze enough to cause crazing - or the opposite shivering.

I have never read anything about this - has anyone seen anything that could
shed some light?

RR


>Could the materials in the dishwasher "soap" weaken the glaze in some way so
>that it will craze? Can it make the glaze leach and will leaching lead to
>crazing?

Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0

James O'Brien on fri 4 apr 08


I dont know whats happened to this thread, I'm a little late to the party.
I make bathroom sinks. When I started 25 years ago I made a lot of stuff
that was not vitreous. I have a sink in my house that I made 20 years ago
that has just started to craze. Thats really delayed. I know that its
because I didn't fire hot enough to get to vitreous. Now I test for
vitreous every month.

Mike

On Thu, Jan 10, 2008 at 5:03 PM, Ron Roy wrote:

> An interesting question from Lili,
>
> Glazes that are short of alumina are more subject to degradation from
> alkalies (soap) - particularly in dish washers. The interesting part is -
> if that was so - the soap attacking the glazes - could that alter the
> expansion of a glaze enough to cause crazing - or the opposite shivering.
>
> I have never read anything about this - has anyone seen anything that
> could
> shed some light?
>
> RR
>
>
> >Could the materials in the dishwasher "soap" weaken the glaze in some way
> so
> >that it will craze? Can it make the glaze leach and will leaching lead
> to
> >crazing?
>
> Ron Roy
> RR#4
> 15084 Little Lake Road
> Brighton, Ontario
> Canada
> K0K 1H0
>
>
> ______________________________________________________________________________
> Clayart members may send postings to: clayart@lsv.ceramics.org
>
> You may look at the archives for the list, post messages, or change your
> subscription settings here: http://www.acers.org/cic/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
> melpots2@visi.com
>