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help! unfired glazes cracking off bisqueware.

updated sat 1 sep 01

 

Shari Smith on thu 30 aug 01


Hello all!

This is my first posting to this list. I happened upon the ClayArt archives
a few weeks ago and was so ever grateful to find such a resource of
knowledge and information. Now I have a dilemma of my own:

I've acquired all the equipment, materials, bits and pieces of another
potter's studio, including glazes which she had already mixed, their age
unknown. I'm just getting started on setting it all in moption as my own
studio. I've done two cone 06 bisque firings already and now I'm starting in
on glazing. But something is definitely wrong. Both glazes (cone 6) I have
applied to the ware are cracking and flaking off the pieces.

Any ideas on what might be causing this and what I can do to make it stop?
Is the clay repelling the glaze? Or does the glaze need some sort of
addition to make it more cohesive? I am stumped. Any advise would be greatly
appreciated.

Many thanks,

Shari Smith
Corvallis, Oregon, Cascadia

Patrick Logue on thu 30 aug 01


Hi Shari
welcome to the show.never a dull moment i've found.
I use veegum-t in my glaze, makes it less powdery and
seems to bond better to the clay.
Pat
--- Shari Smith wrote:
> Hello all!
>
> This is my first posting to this list. I happened
> upon the ClayArt archives
> a few weeks ago and was so ever grateful to find
> such a resource of
> knowledge and information. Now I have a dilemma of
> my own:
>
> I've acquired all the equipment, materials, bits and
> pieces of another
> potter's studio, including glazes which she had
> already mixed, their age
> unknown. I'm just getting started on setting it all
> in moption as my own
> studio. I've done two cone 06 bisque firings already
> and now I'm starting in
> on glazing. But something is definitely wrong. Both
> glazes (cone 6) I have
> applied to the ware are cracking and flaking off the
> pieces.
>
> Any ideas on what might be causing this and what I
> can do to make it stop?
> Is the clay repelling the glaze? Or does the glaze
> need some sort of
> addition to make it more cohesive? I am stumped. Any
> advise would be greatly
> appreciated.
>
> Many thanks,
>
> Shari Smith
> Corvallis, Oregon, Cascadia
>
>
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Paul Lewing on thu 30 aug 01


on 8/30/01 6:33 PM, Shari Smith at sharilynsmith@YAHOO.COM wrote:

> Any ideas on what might be causing this and what I can do to make it stop?
> Is the clay repelling the glaze? Or does the glaze need some sort of
> addition to make it more cohesive? I am stumped. Any advise would be greatly
> appreciated.

Shari, we can't give you any advise, but maybe we can come up with some
advice. (Sorry, can't help myself, and please let's not have that debate
again.)
Basically, we need more information. Probably your raw glaze is being put
on too thick, and probably it has too much raw clay in it or too much
magnesium carbonate, or too much of something that shrinks too much when it
dries. Give us the recipe and we'll take a crack at it.
Paul Lewing, Seattle

WHC228@AOL.COM on fri 31 aug 01


Try a little starch from the grocery store. The kind that is used when
ironing starched shirts.
It makes a pretty good binder and is cheap.
Bill

Paul Brinkmann on fri 31 aug 01


Shari, Sounds like your glaze if to thick. If you are dipping, add a little
water; if you are brushing, thin down the glaze, or brush on only 2 coats.
PG Brinkmann