lili krakowski on sun 30 aug 09
As I know nothing about porcelain I am kinda pressing my nose against =3D
the shop window, trying to look in. Chutzpah slip trailed large...
The first problem was that little lumps appeared in the clay, and the =3D
given answer was that bits of hard clay had fallen into the body as it =3D
was being pugged. As this went on even after the pugmill had had a good =
=3D
amount of clay run through it, which should have cleaned it out, it was =3D
thought there was a chemical reaction between clay and aluminium tube. =3D
This turned out not to be the problem. Or if a problem one that made no =
=3D
never mind...
It then was posited that the lumps came from reclaimed clay. Theory =3D
being that the reclaim was
partly totally dry, partly damp, partly wet, and that the three did not =3D
combine well. Brilliant arguments as to why this was unlikely.
Then we got to Epsom Salts. More, less, only here, never there....It =3D
migrates, it does not migrate, migration does not matter, turn the ware =3D
upside down to dry...
At this point I am totally confused.
Why is no one questioning whether Melissa's clay body is any good? Why =3D
has no one suggested (yet) that she get a few pounds of kaolin and ball =3D
clay, and whatever and make a test? Or get a hold of 25 lbs of other =3D
bodies and try them? I know David Henley slapped my wrist the other =3D
day for suggesting everyone have three clay bodies of every type they =3D
use in their studio--so as to have two "control" ones for when things go =
=3D
wrong with one body. And David is right...but few of us are David, know =
=3D
as much as he does, etc....For the average potter it is a quick and easy =
=3D
"testing method."
My question right now is" WHY does this blipping, blistering happen only =
=3D
on the thrown forms?" Surely Epsom salts will travel--if they do--on =3D
any piece or surface...No?
I think 'twas NeonCat suggested that a higher bisque might be an =3D
idea....It well might--a higher, slow bisque....
I would like to suggest that Melissa smash (yes, smash--wearing goggles, =
=3D
a face mask, and gloves) a really thick fired BISQUE piece, and a thick =3D
glaze fired one--because what is beginning to bug me is that there well =3D
may be blisters INSIDE a thick piece--(been there, done that) that do =3D
not appear on the surface.
I also ("She has SOME nerve!!! No knowledge of porcelain, yet a =3D
suggestion!) think Melissa might consider drying 25 lbs of her clay in a =
=3D
VERY THIN layer--as on a sheet stretched on the grass. Let it dry =3D
completely and then put part of it in a pail of water--with lots of =3D
water, I mean LOTS and disperse it, mix it well--and then sieve that =3D
slop through a VERY fine sieve...
What I am suspecting is that something tiny and soft--something jelly =3D
like, like half a grain of tapioca, is in that clay....goes through a =3D
regular sieve, because it IS soft and jelly like,that it makes blips and =
=3D
blisters as above--but manifests itself ONLY where the clay is thin. =3D20
In fact Melissa might want to fire a piece of that very thin dried out =3D
clay...
=3D20
Lili Krakowski
Be of good courage
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