Kathy on sat 23 nov 02
Hi Dawn,
As long as the slip is designed for bisqueware, it
should work. It really helps to test your slip as much
as you can before commiting to it.
IMHO, thick applications of slips on bisqued pots pop
off more often than thick slips for wetware on wet
pots. Though I must admit, I abandoned the bisqueware
slips after I had just a few losses.
Sometimes I think the composition of my slips
changes slightly as I use up a five gallon bucket.
Some collect little sharp granules, have become less
opaque, or lost some of their borax. Has this ever
happened to you?
Yours,
Kathy Maves
dawn isaacs on sat 23 nov 02
If I am painting slip onto bisque-ware.
1. Will it work as well as if I had done it on leather-hard.
2. Do I put the transparent glaze on straight after and then fire a =
second time or =20
3. Only put the transparent glaze on after the 2nd firing and then =
refire.
Thanks for your advice.
Jerry Coleman on sat 23 nov 02
When I slip on bisuit ware I use a very thin slip, 50 ball clay, 50 kaolin
with oxide additions. I let it dry for about ten minutes and then glaze with
the transparent glaze on top. I've never had any problems with this slip
falling off and the glaze adheres without any problem. I hope this helps.
Jerry
vince pitelka on sat 23 nov 02
Dawn Isaacs wrote"
"If I am painting slip onto bisque-ware.
1. Will it work as well as if I had done it on leather-hard.
2. Do I put the transparent glaze on straight after and then fire a
second time or
3. Only put the transparent glaze on after the 2nd firing and then
refire.
Dawn -
If it is an ordinary clay slip intended for application to damp greenware,
then it will not work at all on bisque ware. In order to paint such a
compound on bisque ware, it must be an engobe, which is a slip formulated
with a lower percentage of plastic ingredients, usually accomplished by
substituting calcined kaolin for some of the regular clays. It also helps
to add a little more flux, especially 5% borax, which helps adhesion through
the early part of the firing.
With a properly formulated engobe (which is essentially an underglaze) you
should be able to apply the glaze right over it.
Good luck -
- Vince
Vince Pitelka
Appalachian Center for Crafts
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
Home - vpitelka@dtccom.net
615/597-5376
Work - wpitelka@tntech.edu
615/597-6801 ext. 111, fax 615/597-6803
http://iweb.tntech.edu/wpitelka/
Lesley Alexander on sun 24 nov 02
Jerry, what clay do you use, what temperature?
Jerry Coleman wrote:
> When I slip on bisuit ware I use a very thin slip, 50 ball clay, 50 kaolin
> with oxide additions. I let it dry for about ten minutes and then glaze with
> the transparent glaze on top. I've never had any problems with this slip
> falling off and the glaze adheres without any problem. I hope this helps.
> Jerry
>
>
Snail Scott on mon 25 nov 02
At 01:08 PM 11/23/02 -0000, you wrote:
>If I am painting slip onto bisque-ware.
>
>1. Will it work as well as if I had done it on leather-hard.
No. It might work, but you will need an engobe to
do this reliably.
>2. Do I put the transparent glaze on straight after and then fire a
second time or
>3. Only put the transparent glaze on after the 2nd firing and then refire.
Depends on the glaze. Unfired engobe will absorb
differently than bare bisque, but so will a fired
engobe, so be aware of thickness. Also, a glaze
applied to an unfired surface over bisque can
sometimes cause a thick engobe layer to reabsorb
water and come off the bisque. Again, though, this
depends on the engobe and the glaze, and on the
clay surface. Go ahead and try you usual glaze
over the unfired engobe, but just test one at a
time, not a whole kilnload at once.
-Snail
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