[Clayart] discussion topics

mel jacobson melpots at mail.com
Wed Jan 8 17:35:52 EST 2020

my new adult student has been working on cone 6, mel6 and our glazes.
she had a firing and a commercial rutile blue glaze ran right off
the pot onto her kiln shelf.  obviously she was puzzled, she also
has some crazy pin holing in that glaze.

in discussing the problem she mentioned to me that she has
programmed a hold at cone 6 for something over 30 minutes.
i told her not to hold at temp.  no need.  that is old wives tales
and in a program kiln who knows if the temp does not rise during the hold.
hit the mark, turn off the kiln.  down fire should be at 1900F.  and, who
knows if you need down firing?  (we all know what carol is doing with
high iron glazes...and most of you know that i fired hare's fur at cone 12
with a down fire. in many cases i turned pots into bright metallic gold.)
but, i was firing all my hare's fur, partridge feather and oil spot glazes
in oxy atmosphere, or only slightly neutral. no reduction.  high iron clay, and
high iron glazes. they look like they come from a fuel, reduction kiln...as in
look like..but not.  that is the key to hare's fur. fired in saggers in a wood
fired, very hot kiln.  no kiln shelves at all.  400 pots fired in a chamber.
the pots were snug in a neutral atmosphere, in a really wild wood fired reduction
kiln.  i have never seen puke green in my firings. clean atmosphere in the kiln.
(many of us saw puke green in that old temmoku recipe of the late 60's. and remember
folks turned the world full of smoke from over reduction..we all did it. not now.
over reduction is a scourge.)

i am convinced that there is a reaction with that high rutile content
glaze sort of boiling at the clay surface.  high iron clay, high iron
glaze. (and i think some titanium) they may not be compatible, or make the bubbles and pin holes part
of the aesthetic. make the so called flaw a new signature glaze.
we did that with colleen and the boiling shino.  now we do not get the
boil...it is back to lovely orange and black basic shino.   it may be as
simple as a dead mouse rotten in the shino.  who knew?  i think it was too
much table salt.

i would love to have others join in on this topic...especially about holding
at temp...i would like to ban it.  only bad things happen.
that is one reason i always fire a new glaze to one cone hotter.  i want to see
what happens.

i fired two bowls with mel6 and our five equal amounts of glaze materials to cone
12 last month.  they looked great...they still had a ring...but, man, that is pushin
to the limit.  how does one know, unless you try to test to limit?

(thanks paul, you know how to push limits too...and we appreciate it. and,  if we
can make our dear woofey jump...that is fun. by the way folks, i have known david
woof since he was a baby wolf. you cannot find a kinder better person to sit and have
a beer with. like paul, he loves controversy like air itself. they make clayart rich.)

website: www.melpots.com

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