Roxanne Hunnicutt on wed 13 apr 11
a paper clay question
here is what happened to a friend: She was making a pot and made some
incisions for a design then decided some were too deep and wanted to replac=
e
them. She put in layers of paper clay to fill the cuts. Then she used her
favorite high calcium glaze that NEVER RUNS.
Over just the paper clay the glaze barely but perceptibly ran.
COULD IT BE that the paper clay makes enough ash to flux a glaze?
Or could it be that the paper clay area soaked up more glaze due to
porosity?
HAS ANYONE EVER SEEN an area of paper clay change a glaze? Anyone ever
suspected the ash of being a factor ...ever?
Thought it was interesting to ponder.
I LOVE MY PAPER CLAY but am not the careful potter that my friend is. She
really is methodical. I might not even have noticed the flow in the glaze
over the paper clay area!
Rox in OR
Pottery by John on thu 14 apr 11
Well that is an interesting question.
My first thought is what kind of paper is your friend using? I bought a
bale of cellulose insulation to use for making paper clay (haven't made any
yet), or paper slip (make that and use it for joins and repairs), after
reading an article from a well known paperclay proponent. The cellulose is
ground up newspaper from all appearances and it treated with a borax
solution as a fire retardant by the manufacturer. The paperclay proponent
stated that the fire retardant also suppressed the bacterial growth that
makes stinky paperclay, which was my reason for going this route. I can't
tell you how much borax is in the paper, but it might be enough to locally
flux the glaze.
My second thought is what do I have in a state that I can dig out some clay
and stuff in some of my paperclay to test this out?! I have a few pots
between thrown and bone dry that are candidates and will select one, try it
out, and report back.
John Lowes
Sandy Springs, Georgia
http://wynhillpottery.weebly.com/
Stephani Stephenson on thu 14 apr 11
Roxanne
in my particular cases I have not
differences in the absorption between the pclay and the other clay might=
=3D
account for some variation, because the glaze would absorb differently. w=
=3D
ho
knows, maybe some soluble materials in the clay or the water came to the
surface more readily and interacted with the glaze. i could see that
happening, but who knows if it really did!
i glazed similar tiles, in similar ways, some paperclay and others not. i=
=3D
n
fact the pclay tests were of varying thicknesses too. There was no
detectable difference in the appearance of the final product.
of course, my tests only, so ....hard to extrapolate.
William & Susan Schran User on thu 14 apr 11
On 4/13/11 11:45 PM, "Roxanne Hunnicutt" wrote:
> Over just the paper clay the glaze barely but perceptibly ran.
>
> COULD IT BE that the paper clay makes enough ash to flux a glaze?
>
> Or could it be that the paper clay area soaked up more glaze due to
> porosity?
>
> HAS ANYONE EVER SEEN an area of paper clay change a glaze? Anyone ever
> suspected the ash of being a factor ...ever?
You don't mention whether the work was raw glazed or bisque fired then
glazed, but from what you ask, I assume bisqued.
I would guess that the area of paperclay was a bit more porous and could
lead to thicker application of glaze.
Bill
--
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com
Snail Scott on fri 15 apr 11
On Apr 13, 2011, at 10:45 PM, Roxanne Hunnicutt wrote:
> COULD IT BE that the paper clay makes enough ash to flux a glaze?
Very definitely, depending on the amount of paper in the formulation.
> Or could it be that the paper clay area soaked up more glaze due to
> porosity?
Quite possible, if the paperclay was bisque-fired before
glazing.If glazed green, I doubt you'd see much difference.
However, I doubt that the modest extra absorbency would
cause greater visible running unless the patch of paperclay
was fairly large and thick.
>
> HAS ANYONE EVER SEEN an area of paper clay change a glaze? Anyone ever
> suspected the ash of being a factor ...ever?
Yes, absolutely. However, my own paperclay efforts used
quite a lot of paper. It was enough, in the highest-paper-
content experiments, to turn a ^4 body into a ^1 body
even without glaze. Glazes are also visibly runnier with
high paper concentrations. As I mainly use vitreous
engobes in my own work, I don't have a very broad-based
range of glaze/paperclay experiments, but ash is clearly
a player in the result.
-Snail
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