Gail Dapogny on wed 31 jul 02
I'm fooling around with a cone 04 firing of some earthenware and need
help. The pieces are not functional and would not be used in any way with
food. I would like to use some stains and am wondering about the following.
1) If I'm staining the bisqued ware and don't plan to use a clear glaze
over the stains,
should I combine the stain with something like ball clay and gerstley
borate as I do with stoneware? Or would a frit be better? Any particular
recipes for this sort of thing?
2) I read in the Rhodes book that I could lightly seal the stains by
spraying with a very thin matt glaze. However, someone mentioned to me
that this might whiten the body (which is terra cotta), and of course I
don't want that. So is there any way of slightly sealing the body by using
something before the firing, either in the stain itself or over it, or
both? I want to keep the rich color. But a very slight sheen would be
welcome.
I've looked around in the archives and in various books, but haven't really
found any answers. Any help would be much appreciated.
----Gail
Gail Dapogny
1154 Olden Road
Ann Arbor, MI 48103-3005
(734) 665-9816
gdapogny@umich.edu
http://www.silverhawk.com/ex99/dapogny (single historical photo - no longer
registered with Silverhawk)
Martin Howard on wed 31 jul 02
Stains can be used just as they are, with a little water.
Or, if you have a white version of the earthenware clay, add stain at about
the rate of 10-15% be weight of dry clay. Then dip or paint it on.
Depends whether you want to let the red earthenware be visible or not.
Of course, glaze it later, if you want a surface different from the natural
clay.
Some stains from Germany can be used at virtually every stage of decorating
pots from green through bisqe to glaze fire.
Martin Howard
Webbs Cottage Pottery
Woolpits Road, Great Saling
BRAINTREE, Essex CM7 5DZ
01371 850 423
martin@webbscottage.co.uk
http://www.webbscottage.co.uk
Updated 6th July 2002
Valice Raffi on thu 1 aug 02
>I'm fooling around with a cone 04 firing of some earthenware and need
help... So is there any way of slightly sealing the body by using
>something before the firing, either in the stain itself or over it, or
>both? I want to keep the rich color. But a very slight sheen would be
>welcome.
Gail;
you mentioned that you were looking for a fired finish, but since the
pieces are not functional, you might want to try wax.
I've been using a product called Crystal Clear Paste Wax, which a
woodworking supply company sold me when I asked for bowling alley wax (a
suggestion from ClayArt). It has a soft sheen and feels great! Plus it
gives me a chance to use my Grandmother's Bakelite shoe brush when I buff
out the wax.
Valice
in Sacramento
Jeanie on wed 7 aug 02
Dear Gail,
What you want can be achieved without subsequently spraying a glaze over
it. If you're thinking about adding the ball clay for fit or
opacity,its not needed for fit and probebly will not lend opacity. But
you can get colors bonded to the surface and with a sheen at o4 by
using a frit-3124 is useful. Mix the stain with the frit in a 1-2
ratio-one unit of frit to two units of stain. More refractory colors
will require more frit. Remember the colors you get will be strongly
affected by the terracotta underneath. If what you want is opaque
colors, try a white slip over the terracotta body,followed by mason
stains in the white slip-I'd start with i cup slip and two T of stain.
Rebisque or apply to greenware and bisque. You canthen use a Gerstley
or frit wash over the colors for sheen. If you need a slip recipe for
that temp. range, just let me know. Good luck
Jeanie in Pa on a day too beautiful to speak its name
Ron Roy on thu 8 aug 02
When I check out Frit 3134 on my glaze calculator I see just enough silica
to start getting durability at cone 6 - if I add 10 silica (90 3124+10
silica) I get a much more durable glaze - at cone 6 and the expansion is
right in the ball park for many cone 6 bodies. If I add another 10% silica
(80 Frit +20 silica ) I get an even better situation - good enough to over
come twice as much stain? Somehow I doubt that but it depends on the stain
I suppose.
If I use 80 F3124, 10 ball clay and 10 silica I have what might test out to
be a durable glaze - if it is well melted and not overloaded with stain.
All this does not help with absorbency of course - if the foot is not
glazed - and even if it is it only takes a pinhole or two to let the
moisture in - or crazing - or a chip.
My usual advice is - go to cone 6 - clays can be vitrified - lots of glazes
available - and some are even durable - chipping is not the problem it is
at lower cones and glaze materials are much cheaper cause you don't have to
use so much Frit.
RR
>Dear Gail,
>What you want can be achieved without subsequently spraying a glaze over
>it. If you're thinking about adding the ball clay for fit or
>opacity,its not needed for fit and probebly will not lend opacity. But
>you can get colors bonded to the surface and with a sheen at o4 by
>using a frit-3124 is useful. Mix the stain with the frit in a 1-2
>ratio-one unit of frit to two units of stain. More refractory colors
>will require more frit. Remember the colors you get will be strongly
>affected by the terracotta underneath.
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
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