Tony Ferguson on fri 13 jun 08
Folks: diamond disk or masonry surface diamond disk on a 4.5 inch or similar grinder. It will remove anything, including the shelf if you are not careful.
Tony Ferguson
Lili Krakowski wrote: Ok. It's like this. It's like getting beet stains off the white
tablecloth. It is like getting grease off your blue suede shoes. (It also
is like "getting that man out of your hair"--but that is for a girls' night
out.)
Sure it can be done. But at a high cost.
The idea of sand or of kiln wash is to provide an interfacing between the
glaze that runs and the shelf. Think of the kiln wash as a coater, a mat.
So there are stages of stain vs removal "price". Under the best
circumstances the glaze that runs sticks only to the kiln wash, and the
whole pot, with a layer of kiln wash stuck on, is pulled of the shelf, and
all the grinding advice already given applies.And by the way I not only wear
safety goggles when doing this, but also a mask, as the bitseys of glaze can
cut the skin.
Second stage is that the glaze turned very fluid indeed, not only ran onto
the kiln wash, but soaked through it. As the kiln wash is refractory, the
glaze just kinda, and only "kinda" fuses it. The kiln wash becomes hard and
brittle (also sharp at the edges) and can be chipped off the shelves with
minimal damage to the shelves. Again the advice given has been excellent.
Between us my favorite all time glaze cleaning chisel has been an old wood
cutting chisel--about 2" wide--whose previous owner already had removed the
wooden handle and hammered the metal socket into a mushroom.
The third stage is the worst--where the glaze had entered and permeated the
shelf. This is as though your beet juice had gone through the tablecloth,
through the table top finish, and into the wood itself.
At this point one has to make cruel decisions. Some people turn the shelf
over and trust that the shelf will not drip its glaze content on what is
below. Some people put more wash atop the shelf and fire it bare a couple
of times in the hope the new coating of wash will sop up whatever comes out
of the shelf. If it does, they chip that off, and re-wash, etc. As
glaze content weakens the shelf, I am suspicious, and think this can lead to
a horrid enforcement of Murphy's Law and the shelf will give up at the worst
possible time.
My own personal use for those shelves is to use them for bisque only. In
all my years I have produced maybe three such shelves,
because I really belong to the belt and suspender school of thought when it
comes to studio equipment.
So:
ALWAYS test your glazes a couple of times, and test them on flat as well as
vertical test tiles. Have test tiles tall enough so that
it is not half an inch of glaze running down, if it does, but a good two
inches. ALWAYS check out your application method on test tile FIRST. That
means double application, heavy application, two different glazes on top of
one another, colorant painted on the glaze. Try to keep an old shelf, or a
damaged one, just for tests. So if there is more damage no big deal. Keep
your shelf washing up to date. Do not stint. It's a silly job, but only
one of many around the studio.
Make yourself "biscuits" of well grogged high fire clay. These are flat
cookies of clay, maybe 1/8 of an inch thick, that you coat with kiln wash.
Put them under pots that might drip.
Lili Krakowski
Be of good courage
Tony Ferguson
315 N. Lake Ave. Apt 312
Duluth, MN 55806
...where the sky meets the lake...
Artist, Educator, Photographer, Film Maker, Web Meister
fergyart@yahoo.com
(218) 727-6339
http://www.tonyferguson.net
Lili Krakowski on fri 13 jun 08
Ok. It's like this. It's like getting beet stains off the white
tablecloth. It is like getting grease off your blue suede shoes. (It also
is like "getting that man out of your hair"--but that is for a girls' night
out.)
Sure it can be done. But at a high cost.
The idea of sand or of kiln wash is to provide an interfacing between the
glaze that runs and the shelf. Think of the kiln wash as a coater, a mat.
So there are stages of stain vs removal "price". Under the best
circumstances the glaze that runs sticks only to the kiln wash, and the
whole pot, with a layer of kiln wash stuck on, is pulled of the shelf, and
all the grinding advice already given applies.And by the way I not only wear
safety goggles when doing this, but also a mask, as the bitseys of glaze can
cut the skin.
Second stage is that the glaze turned very fluid indeed, not only ran onto
the kiln wash, but soaked through it. As the kiln wash is refractory, the
glaze just kinda, and only "kinda" fuses it. The kiln wash becomes hard and
brittle (also sharp at the edges) and can be chipped off the shelves with
minimal damage to the shelves. Again the advice given has been excellent.
Between us my favorite all time glaze cleaning chisel has been an old wood
cutting chisel--about 2" wide--whose previous owner already had removed the
wooden handle and hammered the metal socket into a mushroom.
The third stage is the worst--where the glaze had entered and permeated the
shelf. This is as though your beet juice had gone through the tablecloth,
through the table top finish, and into the wood itself.
At this point one has to make cruel decisions. Some people turn the shelf
over and trust that the shelf will not drip its glaze content on what is
below. Some people put more wash atop the shelf and fire it bare a couple
of times in the hope the new coating of wash will sop up whatever comes out
of the shelf. If it does, they chip that off, and re-wash, etc. As
glaze content weakens the shelf, I am suspicious, and think this can lead to
a horrid enforcement of Murphy's Law and the shelf will give up at the worst
possible time.
My own personal use for those shelves is to use them for bisque only. In
all my years I have produced maybe three such shelves,
because I really belong to the belt and suspender school of thought when it
comes to studio equipment.
So:
ALWAYS test your glazes a couple of times, and test them on flat as well as
vertical test tiles. Have test tiles tall enough so that
it is not half an inch of glaze running down, if it does, but a good two
inches. ALWAYS check out your application method on test tile FIRST. That
means double application, heavy application, two different glazes on top of
one another, colorant painted on the glaze. Try to keep an old shelf, or a
damaged one, just for tests. So if there is more damage no big deal. Keep
your shelf washing up to date. Do not stint. It's a silly job, but only
one of many around the studio.
Make yourself "biscuits" of well grogged high fire clay. These are flat
cookies of clay, maybe 1/8 of an inch thick, that you coat with kiln wash.
Put them under pots that might drip.
Lili Krakowski
Be of good courage
Kim Hohlmayer on tue 17 jun 08
Hi Lily,
I see that you are indeed wise. I am currently in an art center where anything can go wrong and usually does. This also means that we have no money to replace expensive items like shelves unless we beg, pray and wait a year until the next grant comes through(many blessings upon the head of the boss lady who writes our grants or we would have nothing at all).
All this said, I too go for prevention. When I load a glaze kiln full of student work I put broken pieces of kiln shelf under any piece that is even remotely suspect. I have also rescued any reasonably flat piece of discarded, clean bisque and kiln washed them so I have thinner, less costly (energy wise) glaze run catchers. For test tiles I use discarded pinch pots under them.
The art center where I first cut my teeth on clay and kilns had as its head potter a wonderful man and still good friend who carried kiln care to the next level. You talked of bisque tiles for under your test tiles but this guy rolled slabs by hand (no roller there) and with a variety of circle cookie cutters cut out enough circles to put under every pot the center fired. And that was a lot of pots! He also threw test cups off the hump and ran his tests on the inside so they only could run down into the little cup and never on to the shelf. Needless to say, I never remember either of us cleaning a shelf the entire time I was there.
--Kim H.
--- On Fri, 6/13/08, Lili Krakowski wrote:
> From: Lili Krakowski
> Subject: Getting Glaze Off Shelves!!!
> To: CLAYART@LSV.CERAMICS.ORG
> Date: Friday, June 13, 2008, 12:08 PM
> Ok. It's like this. It's like getting beet stains
> off the white
> tablecloth. It is like getting grease off your blue suede
> shoes. (It also
> is like "getting that man out of your hair"--but
> that is for a girls' night
> out.)
>
> Sure it can be done. But at a high cost.
>
> The idea of sand or of kiln wash is to provide an
> interfacing between the
> glaze that runs and the shelf. Think of the kiln wash as
> a coater, a mat.
>
> So there are stages of stain vs removal "price".
> Under the best
> circumstances the glaze that runs sticks only to the kiln
> wash, and the
> whole pot, with a layer of kiln wash stuck on, is pulled of
> the shelf, and
> all the grinding advice already given applies.And by the
> way I not only wear
> safety goggles when doing this, but also a mask, as the
> bitseys of glaze can
> cut the skin.
>
> Second stage is that the glaze turned very fluid indeed,
> not only ran onto
> the kiln wash, but soaked through it. As the kiln wash is
> refractory, the
> glaze just kinda, and only "kinda" fuses it. The
> kiln wash becomes hard and
> brittle (also sharp at the edges) and can be chipped off
> the shelves with
> minimal damage to the shelves. Again the advice given has
> been excellent.
> Between us my favorite all time glaze cleaning chisel has
> been an old wood
> cutting chisel--about 2" wide--whose previous owner
> already had removed the
> wooden handle and hammered the metal socket into a
> mushroom.
>
> The third stage is the worst--where the glaze had entered
> and permeated the
> shelf. This is as though your beet juice had gone through
> the tablecloth,
> through the table top finish, and into the wood itself.
>
> At this point one has to make cruel decisions. Some people
> turn the shelf
> over and trust that the shelf will not drip its glaze
> content on what is
> below. Some people put more wash atop the shelf and fire
> it bare a couple
> of times in the hope the new coating of wash will sop up
> whatever comes out
> of the shelf. If it does, they chip that off, and
> re-wash, etc. As
> glaze content weakens the shelf, I am suspicious, and think
> this can lead to
> a horrid enforcement of Murphy's Law and the shelf will
> give up at the worst
> possible time.
>
> My own personal use for those shelves is to use them for
> bisque only. In
> all my years I have produced maybe three such shelves,
> because I really belong to the belt and suspender school of
> thought when it
> comes to studio equipment.
>
> So:
>
> ALWAYS test your glazes a couple of times, and test them on
> flat as well as
> vertical test tiles. Have test tiles tall enough so that
> it is not half an inch of glaze running down, if it does,
> but a good two
> inches. ALWAYS check out your application method on test
> tile FIRST. That
> means double application, heavy application, two different
> glazes on top of
> one another, colorant painted on the glaze. Try to keep an
> old shelf, or a
> damaged one, just for tests. So if there is more damage no
> big deal. Keep
> your shelf washing up to date. Do not stint. It's a
> silly job, but only
> one of many around the studio.
>
> Make yourself "biscuits" of well grogged high
> fire clay. These are flat
> cookies of clay, maybe 1/8 of an inch thick, that you coat
> with kiln wash.
> Put them under pots that might drip.
>
> Lili Krakowski
>
> Be of good courage
Steve Mills on tue 17 jun 08
Kim
That rings a bell;
at Farnham College (UK) where I learnt, the same technique applied, only we made small balls of clay and rolled them wafer thin on fine sand (today I use Alumina), both sides. After the firing they got gathered up and re-used if they were pristine.
We didn't clean shelves either!
Steve
Bath
UK
--- On Tue, 6/17/08, Kim Hohlmayer wrote:
From: Kim Hohlmayer
Subject: Re: Getting Glaze Off Shelves!!!
To: CLAYART@LSV.CERAMICS.ORG
Date: Tuesday, June 17, 2008, 4:23 PM
The art center where I first cut my teeth on clay and kilns had as its
head potter a wonderful man and still good friend who carried kiln care to the
next level. You talked of bisque tiles for under your test tiles but this guy
rolled slabs by hand (no roller there) and with a variety of circle cookie
cutters cut out enough circles to put under every pot the center fired. And
that was a lot of pots!
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