KarenY31 on wed 6 may 98
My Mason stains are exploding (?) off the ware during firing, either fast
(11hrs) or slow (17hrs) to cone 5, oxidation. While the painted design is
intact, though not totally solid color, stain dusts coat the inside bottom of
bowls. It looks like fine colored speckles. It is noticable with any of the
strong colors. I'm am handling the ware carefully so as not to touch the
painted surface. Whether dipped in glaze recently or a few days prior, it
makes no difference.... While the effect could be employed nicely on plates,
it's not great on bowls. And, I'd like a little control.
I've tested many ratios of Frit 3124 to stain and it makes no difference.
The problem is solved by mixing the stain into the base glaze but I prefer the
simplicity and 'feel' of simply Frit/stain/water.
I've added Acrylic floor polish and liquid starch to the mix without
sucess. The Gerstley Borate (substituted for Frit) was not as attractive,
washed out color.
The Mason stain technical advisor suggested Vee gum T, not Vee gum S or C
or whatever. Of course, I have gum arabic, not Vee gum T, and decided to try
it prior to ordering the new product. No luck. SO, the next question is
"What is the difference between Vee gum T & Gum arabic?" Can I expect
improvement?
Any suggestions where to go from here? If I must mix the stain into the
base glaze is their a good & simple recommended method? When the stain is
mixed in the base glaze can you still get a 'watercolor look' and wash stains
over each other so different colors are created at the overlap?
The Mason stain person did not think that my white glaze presented
problems but here it is for scrutiny.
% MAJOLICA ^ 5
25 Gerstley Borate
38.5 Feldspar Kona F4
8.5 Kaolin EPK
8.5 Whiting
19.5 Flint
15 Zircopax
Karen in Colorado Springs
gambaru on thu 7 may 98
Because your receipe contains gerts and zir, which will affect colours, why
not use/test Tony Hansen's base cone 5-7 clear as your carrier for stains.
http://digitalfire.com Might just be a good starting point. MB
-----Original Message-----
From: KarenY31
To: Multiple recipients of list CLAYART
Date: Wednesday, May 06, 1998 7:48 AM
Subject: Mason stains exploding powder & Gums
>----------------------------Original message----------------------------
> My Mason stains are exploding (?) off the ware during firing, either
fast
>(11hrs) or slow (17hrs) to cone 5, oxidation. While the painted design is
>intact, though not totally solid color, stain dusts coat the inside bottom
of
>bowls. It looks like fine colored speckles. It is noticable with any of
the
>strong colors. I'm am handling the ware carefully so as not to touch the
>painted surface. Whether dipped in glaze recently or a few days prior, it
>makes no difference.... While the effect could be employed nicely on
plates,
>it's not great on bowls. And, I'd like a little control.
> I've tested many ratios of Frit 3124 to stain and it makes no
difference.
>The problem is solved by mixing the stain into the base glaze but I prefer
the
>simplicity and 'feel' of simply Frit/stain/water.
> I've added Acrylic floor polish and liquid starch to the mix without
>sucess. The Gerstley Borate (substituted for Frit) was not as attractive,
>washed out color.
> The Mason stain technical advisor suggested Vee gum T, not Vee gum S
or C
>or whatever. Of course, I have gum arabic, not Vee gum T, and decided to
try
>it prior to ordering the new product. No luck. SO, the next question is
>"What is the difference between Vee gum T & Gum arabic?" Can I expect
>improvement?
> Any suggestions where to go from here? If I must mix the stain into
the
>base glaze is their a good & simple recommended method? When the stain is
>mixed in the base glaze can you still get a 'watercolor look' and wash
stains
>over each other so different colors are created at the overlap?
> The Mason stain person did not think that my white glaze presented
>problems but here it is for scrutiny.
>% MAJOLICA ^ 5
>25 Gerstley Borate
>38.5 Feldspar Kona F4
>8.5 Kaolin EPK
>8.5 Whiting
>19.5 Flint
>15 Zircopax
>Karen in Colorado Springs
>
Anne W. Bracker on thu 7 may 98
Dear Karen,
Gum arabic, or Tragacanth, is a vegetable gum that can be added to glazes
to give a harder coating when dry. Since it is organic, it can decay and
smell after awhile, as well as ruin a glaze. Veegum T(as per the MSDS)
is hydrated magnesium aluminum silicate, synomyn = smectite clay. It is
also a surface hardener as well as a suspension agent.
Here is a possiblity for you to try with your current clay and glaze.
I have a customer who works in cone 5/6 porcelain and Mason stains. This
is how she glazes.
She dip or pours her glazes (in order to acheive a certain thickness
necessary for the Mason Stains to not exhibit their refractory nature.).
Let the piece dry. She then sprays the piece with the least expensive
laundry spray starch that she can find. Let the piece dry. She then
decorates using Mason Stains and water in an "inky" solution. Fire in
your electric kiln. You should try this method on a test piece.
P.S. As per Pete Pinnell, the frit/gerstley/stain formula is typically
used for low fire decoration. Maybe there's a problem with too much flux
material for your glaze.
Good luck,
Anne
Bracker's Good Earth Clays, Inc.
1831 E 1450 Road
Lawrence, KS 66044
1 785 841-4750 OFFICE
1 785 841-8142 FAX
1 888 822-1982 ORDER LINE
bracker@midusa.net E-MAIL
"Clay Ain't Dirt"
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