Janet Kaiser on fri 24 mar 00
------------------
I believe it is true to say, that crazing on old and well used pottery, =
crockery
and domestic pots is usually the result of years of use and abuse. It is
naturally perfectly safe to eat and drink out and from. It has been in the
family for years and something we do not even think about, although we tend =
not
to serve dinner to guests on it=21
However, I would personally not want a new plate, cup or any other item I am
going to eat or drink out of or from to be crazed. I would certainly not buy
ware that has crazed, or sell it either.
=22Why not?=22 some of you would ask? Because there is no way of telling if =
this is
=22cosmetic=22 or somewhat more serious crazing. Cosmetic would be a glaze =
which has
crazed but is stable in that it is still well and truly fused to the body. =
Sort
of crazed, but not terminally so=21
=22Serious=22 crazing is where little to no fusion has taken place or has =
been
severed by the crazing process. Like most people, I would not enjoy slivers =
of
glaze ending up in my food and drink=21 It does not seem unreasonable to say=
so.
I have seen what started as very slight (almost invisible) crazing continue =
to
such an extent, that one year later the item had lost most of the glaze and =
the
stained / coloured slip underneath. Being a lidded box, it was never washed =
up
or used to eat from. No knives and forks scraping across and no dish-washer
subjecting it to hot and cold temperature changes, including steaming.
Call me a cynic, but I would never trust a potter who claims their crazing =
is
intentional and perfectly safe on domestic ware. I would still be pretty
doubtful if anything low-fired showed signs of crazing. The only exception =
to
this being raku, where crazing is often a highly desirable part of the pot.
Is this all prejudice? Well, no I don't think so. I support makers pushing
boundaries in many ways, but some of the basic truths and traditions will =
never
be proved untrue or disappear.
Janet Kaiser - Back to wind and rain after a whole week of spring sunshine =
and
warm days. Ideal weather for woodworm hunts.
The Chapel of Art, Criccieth LL52 0EA, GB-Wales
Home of The International Potters Path
TEL: (01766) 523570
WEB: http://www.the-coa.org.uk
EMAIL: postbox=40the-coa.org.uk
Sheron Roberts on sat 25 mar 00
------------------
It has been a while since I visited
Pier I. I went Tuesday with
my sister and much of the new
dinnerware, (cups, mugs, plates,etc.)
were crazed, big crazies.
I looked on the back of a plate,
it just read, dishwasher safe, made
in china, might have read stoneware too,
can't remember, but nothing was said
about food safety.
I picked up a nearby vase, it read
on the bottom, do not use as a food
container, may poison food.
So I supposed that those buying the
dinnerware would see it as food safe.
I agree with Janet, that not knowing
the glaze particulars, I would not
purchase any of the dinnerware. But
I would make my own before I paid
that much for =22store bought=22 ware,
anyway.
But someone at Pier I thinks its OK,
or they would not leave themselves
wide open for a law suit. Makes
me wonder if their purchasing
agent checks into these kind of things.
I did find out this week after opening my
kiln, that it is not firing to temperature.
So the bisque is not reaching the
temperature I want it to. May be the
problem alltogether. I added a
one hour soak to the glaze firing and
the glazes that have been bubbling
are simply beautiful, smooth and even.
No trips, no runs, no errors. (just kidding).
I tried the crazing glaze on a different
clay body, a buff as opposed to a white,
and no crazing=21 This doesn't mean I
will change clays. I will still work with
the crazing glazes a little to see if I
can work out the bugs, or er the cracks.
Sheron in NC
-----------------------------------------------------
Click here for Free Video=21=21
http://www.gohip.com/freevideo/
Ray Aldridge on tue 28 mar 00
Janet, I think you may be confusing the differences between crazing and
shivering, which are opposites. The latter is a much more severe defect--
a pot that shivers would never be sold by any ethical potter, because it's
actively dangerous. Another colloquial term for shivering is
"edge-chipping" so-called because the glaze pops off the edges first. In
extreme cases, shivering can cause a pot to shatter.
Crazing, on the other hand, is very unlikely, at least on high-fired pots,
to cause the glaze to come off. It's a cosmetic defect, though some would
argue that it's unhygienic. It's a different matter with low-fired work,
and here you are absolutely correct that it is a fault that should be
rejected by buyers, because a crazed glaze will seep moisture into the
permeable body of the low-fired pot.
Crazing has indeed been used as an intentional decorative motif by some
porcelain and stoneware potters. Certain classic glazes are by their
nature going to craze-- the feldspathic "mutton fat" glazes beloved of some
traditionalists will almost always craze on a normal body. If you refuse
to buy crazed glazes, you would be rejecting some of Bernard Leach's best
pots.
More modern potters have also used crazing to good effect. One well-known
technique is to allow a pot to craze and then wipe fine pigment into the
craze lines, and refire the pot. The pigment marks the craze lines
permanently, but new ones will appear, which can be wiped with another
color, and so forth. Very rich effects are possible. Your countryman,
Geoffrey Swindell, used a variant of this technique to brilliant effect.
More conventional crazing is often enhanced by soaking the pot in strong
tea. The Chinese, so I understand, would enhance the craze lines of their
pots by submerging them in cesspools for several months. I would prefer
the modern approach.
Minor cases of shivering, it's true, will look much like crazing, but a
potter who understands glaze calculation to any extent will know which one
he's got, because the calculated expansion for a shivering glaze will be
much below his other more normal glazes. If you have any doubt as to the
origin of the "crackle" you see on a pot offered to you as a gallery owner,
you could request the glaze formula and look to see if it has an unusually
low expansion.
Anyway, just a few thoughts on this subject. I hope the glaze gurus will
comment further about this, because it would be a shame if a bias against
crazing became general. It's one of those things that have to be judged in
context-- is it intentional, for effect? Is it an irreducible adjunct to a
certain kind of glaze surface? To give another example of this, who among
us would reject a Lucie Rie crater-glazed bottle, because it was blistered?
Ray
At 04:18 PM 3/24/00 EST, you wrote:
>----------------------------Original message----------------------------
>------------------
>I believe it is true to say, that crazing on old and well used pottery,
crockery
>and domestic pots is usually the result of years of use and abuse. It is
>naturally perfectly safe to eat and drink out and from. It has been in the
>family for years and something we do not even think about, although we
tend not
>to serve dinner to guests on it!
>
>However, I would personally not want a new plate, cup or any other item I am
>going to eat or drink out of or from to be crazed. I would certainly not buy
>ware that has crazed, or sell it either.
>
>"Why not?" some of you would ask? Because there is no way of telling if
this is
>"cosmetic" or somewhat more serious crazing. Cosmetic would be a glaze
which has
>crazed but is stable in that it is still well and truly fused to the body.
Sort
>of crazed, but not terminally so!
>
>"Serious" crazing is where little to no fusion has taken place or has been
>severed by the crazing process. Like most people, I would not enjoy
slivers of
>glaze ending up in my food and drink! It does not seem unreasonable to say
so.
>
>I have seen what started as very slight (almost invisible) crazing
continue to
>such an extent, that one year later the item had lost most of the glaze
and the
>stained / coloured slip underneath. Being a lidded box, it was never
washed up
>or used to eat from. No knives and forks scraping across and no dish-washer
>subjecting it to hot and cold temperature changes, including steaming.
>
>Call me a cynic, but I would never trust a potter who claims their crazing is
>intentional and perfectly safe on domestic ware. I would still be pretty
>doubtful if anything low-fired showed signs of crazing. The only exception to
>this being raku, where crazing is often a highly desirable part of the pot.
>
>Is this all prejudice? Well, no I don't think so. I support makers pushing
>boundaries in many ways, but some of the basic truths and traditions will
never
>be proved untrue or disappear.
>
>
>
>Janet Kaiser - Back to wind and rain after a whole week of spring sunshine
and
>warm days. Ideal weather for woodworm hunts.
>The Chapel of Art, Criccieth LL52 0EA, GB-Wales
>Home of The International Potters Path
>TEL: (01766) 523570
>WEB: http://www.the-coa.org.uk
>EMAIL: postbox@the-coa.org.uk
>
Aldridge Porcelain and Stoneware
http://www.goodpots.com
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