Paul Taylor on wed 28 nov 01
Dear Brian and all .
As I wrote to Tony. The biggest argument against raw glazing is that the
establishment is set against it and people have forgotten how to do it.
There is one last experiment I would encourage you to try with one of them
porcelain cups. If any body else is interested it is a very successful way
of raw glazing,
The handle on the cup will dry out quicker so waite until the handle is
the same hardness as the cup - just off leather hard - just showing a
little dryness - (as hard as you would turn a pot but curse that you did
not get to the pot sooner). If you live in Arizona you will need a damp
cupboard to dry the pot off evenly.
Then dip the pot upside down in the glaze. If you are careful you will not
glaze the bottom of the pot and keep the glaze out of the inside . You need
lots of glaze and a steady hand . You will notice that many chinese pots
that were rawglazed the foot ring could be got hold of and was not glazed -
or some trick was used like the one you saw . Other wise it is a bit tricky
with the rim. you can hold the pot inside (no glaze) and out (no glaze).
You will get some glaze on the inside (round the rim). this you can thin
down or wipe off with a finger or sponge --- all this takes practice.
When the pot is as dry as you first glazed it you can pore the inside
and rotate the glaze out as you pore it out --- if you get any glaze on the
outside you are in a real muddle - so don't. you can see how some designs
may mitigate against raw glazing.
It is very important to glaze the inside of the pot in the same state of
dryness as you first glazed the outside . Why ? if the pot had become over
dry before you glazed it you will probably get away with it but you have to
let the outside (Whole pot) dry completely before you can glaze the inside
otherwise you will get the body bubbling . It is strange that if you keep a
certain amount of water in the cay and do out side then the inside this
bubbling will not occur but the rule still applies let the pot dry out to
the same consistency before glazing the inside or the body will slump or
crack or bubble. It is this under standing that is the secret to rawglazing
and becomes instinctive after a while. The reason you do the outside first
is so the handle does not dry out completely on the outside while you waite
for the inside to dry otherwise the handle absorbs too much glaze and
bubbles and cracks - If the pot has no handles you can do the inside first.
but I prefer the other way because you do not get a double layer of glaze on
the inside top.
I used to glaze the inside first and then dry the pot if It didn't matter
about a double layer of glaze on the inside rim . I used to glaze the
inside as soon as the handles had set.
There are other ways but it depends on your glaze and clay. my glaze only
has 10- 15 % ball clay so the pots are better on the dry side.
To conclude if you are going to raw glaze then the pots have to be designed
to accommodate it . This sounds a bigger deal than it is. and your equipment
and or attention is going to have to be there as well. But that's habit -
give it a go and tell me if it works for you.
--
Regards from Paul Taylor
There is no such fury as self interest posing as moral principle.
http://www.anu.ie/westportpottery
> From: Brian Molanphy
> Reply-To: Ceramic Arts Discussion List
> Date: Tue, 27 Nov 2001 14:16:09 -0700
> To: CLAYART@LSV.CERAMICS.ORG
> Subject: single firing (paul taylor)
>
> paul wrote:
>
> According to Nigel Woods the glazes were built up on some guan (kuan)
> wares in layers managed by repeat low firings. Does that suggest a biscuit
> as we know it . I suspect Chinese kilns took a long time to fire due to
> their thermal mass so there was no need to biscuit. The shape of the pots
> and all other factors allowed raw glazing .
>
> Like every thing raw glazing is easy if you do it properly... One
> has to looked at specific pots and glazes to plan how to raw glaze them and
> some shapes and glazes are self evidently not worth raw glazing. While
> others it would be short sighted not to.
>
> thanks, paul. that makes sense. if, as i recall, the kuan pots were for
> royal table, such elaborate measures were probably practiced. (i'll pass.)
> your advice on glazing according to shape, etc is well-taken. so far my
> efforts to raw glaze, for example, thin porcelain teacups, have not
> succeeded. they slump while drying. fodder for the biscuit kiln maybe.
> still... i remember with awe a video of jingdezen (?) at the denver nceca.
> it showed potters trimming porcelain bowls after they had been glazed,
> leaving a nice even glaze edge at the bottom.
>
> best, brian
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