[Clayart] Sea shells in the kiln?
claywork at flying-snail.com
Tue Jan 3 15:57:35 EST 2017
> On Jan 3, 2017, at 7:56 AM, Ken Chase <kchase235 at gmail.com> wrote:
> I really like the idea of a glazed foot ring.
If you glaze the footring, you’ve gotta have some other way
to hold the piece up in the kiln. (Sometimes I fire things (not pots)
on pedestals that sit inside or up from the lowest point of the art,
so that the low points can be glazed. For my sculptural things, it
makes sense for some forms and not others. If you don’t leave
unglazed spot(s) for such supports, then you have to work stilt
scars into your design instead. You will see the classic standard
stilt scars on a lot of commercial stoneware dinnerware that has
glazed footrings - little dents or tick marks in the glaze, three or four
of them evenly spaced around the underside. The shells mentioned
previously are an example of making a virtue of necessity, by using
the ornamental shells in place of some merely functional stilts, and
planning for the esulting marks as part of the design.
It can be tricky to position the work in the kiln on top of the stilts (no
matter what kind), so a little dab of Elmer’s or white craft glue can
hold them in place on the clay object as you load.
If you have a very runny glaze, be aware that it may run down the
stilt and stick it in place, preventing it from breaking off cleanly. It may
also drip unevenly from the footring, leaving it un-level and requiring
grinding to level it anyway, substantially eliminating the appeal of
having a glazed foot.
Some people have made a virtue of this, using the drips of the glaze
as ‘feet’, lifting the whole piece up off its nominal bottom by the thickness
of the drips. When it works well, it can be quite ornamental, but since
drips - even planned ones - aren’t always equal in depth, these end up
(ideally) sitting on their three deepest drips like a tripod, but may require
at least enough grinding to make three relatively coplanar points to level
the piece. Plenty of water is needed when grinding glaze drips, since if
they overheat, they can shatter and break off entirely.
A nice aesthetic compromise might involve an outer ‘false foot’ that
the glaze is allowed to drip off of, and a deeper inner foot that actually
supports the piece but is somewhat hidden underneath, behind the
drips. Obviously, a catch slab or some such would be needed under the
drip zone. With practice, you can predict the amount of dripping with fair
accuracy, but never perfectly.
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