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slipping bisqued ware/slip on earthenware

updated thu 15 aug 02


Ann Brink on wed 14 aug 02

Antoinette wrote: (snip)" My suggestion will be that if you really want to
get all problems out of the way, you will have to add some glaze components
to your slip and change it to
an englobe. The very first time that there is a slight change in your
surcumstansas,your slip will start peeling or flaking."

I just learned a lesson this week about something similiar: I used a
porcelain slip on an earthenware plate, applied when leather hard. I used
the slip because I planned to use a yellow glaze and knew it would brighten
up the yellow. (The part of my brain in charge of hoisting warning flags was
not working apparently) Anyway, after the glaze firing it looked good. I
always let my local earthenware stuff sit out in the air for about a week,
just in case there are incipient lime-pops, I want them to happen before the
customer gets the piece. Usually there aren't any.

So the other day I looked at the plate again, saw a tiny bulge on the
surface, pressed it with my fingernail, and DAMN, it was like peeling an
egg. Dry surface of the earthenware, the slip had not melded with the clay
at all. When I've done this before, I guess the clay has been much wetter,
like right on the wheel, and the slip became an integral part of the

And my first thought was, I better get some flux into that slip. And use
some low-fire white slip to begin with. I have enough knowledge to diagnose
after the fact....I guess it's like Mel says, "Think!".

Ann Brink in CA...who gleaned at least 2 things from yesterdays CLAYART:
Try Shellac as a resist (Bill Campbell), get some wallpaper paste for
refiring glazes (Charles Moore)...Thanks!