Sue Hintz on wed 19 feb 97
Has anyone had success with the maroon colored mason
staines and slips? I was told to add whiting to
my slip to keep it from burning out. I haven't fired
the test yet. Any suggestions? I fire ox. at cone 5.
Jonathan Blitz on wed 19 feb 97
Mason reccomends that you use at least 15% whiting or some other calcium
compound and use absolutely NO ZINC.
Jonathan Blitz
President
Applied Aluminosilicates, Ltd.
aal@inlink.com
http://www.iwc.com/krueger/aalhome.html
8153 Big Bend
St. Louis, MO 63119
314.963.0180
Craig Martell on thu 20 feb 97
At 10:43 AM 2/19/97 EST, you wrote:
>----------------------------Original message----------------------------
>Has anyone had success with the maroon colored mason
>staines and slips? I was told to add whiting to
>my slip to keep it from burning out. I haven't fired
>the test yet. Any suggestions? I fire ox. at cone 5.
Hi Sue:
If the maroon stain you refer to is chrome-tin based, I would say that you
will probably have some difficulty getting a good color, or any at all. The
addition of Calcium (whiting) to the slip will help because chrome-tins are
reliant on Calcium in GLAZES to develop color. Mason recommends 15% Calcium
in glazes for the chrome-tin colors, i.e. pinks, reds, mauve, maroon. I
don't think that the colorants actually burn out especially at cone 5. They
just don't develop in the presence of all that alumina, which is said to be
a color inhibitor, and need the calcium, usually not present in most slips.
You might want to run some tests though and lower the alumina content of the
slip base, which will increase the flux percentage in relation to the
Al/Si02, and better the chances of getting the color you want. The first
thing I would try is jut the addition of whiting. I hope that you can prove
me wrong on this and get the color that you are looking for. Mason has a
chart that gives information on which stains can be used as body colorants
and the chrome-tin stains are not recommended, this would mean slips too I
guess.
I hope you break some new ground, Craig Martell-Oregon
Carl Ross on thu 20 feb 97
Sue,
I suggest you order a mason stain color chart,
On mine I see no mention of maroon, but for the crimsons they suggest a
maximum Firing temp of 2300 degrees F, not to use zinc, and it says :
Calcium oxide content as calcium carbonate should be between 12 - 15% for
best color development. Adding the molecular equivalent of calcium oxide with
wollastonite, a natural calcium silicate, often gives better uniformity. The
increased silica from the wollastonite must be subtracted or the glaze will
have poor surface.
Glaze must contain 6.7 to 8.4% CaO (12 - 15% CaCO3)
I hope that helps,
Carl in Phillips
sam wainford on fri 21 feb 97
Sue Hintz wrote:
>
> ----------------------------Original message----------------------------
> Has anyone had success with the maroon colored mason
> staines and slips? I was told to add whiting to
> my slip to keep it from burning out. I haven't fired
> the test yet. Any suggestions? I fire ox. at cone 5.
Sue,
I did some tests using Mason stain 6381 which held its color up to cone
9 fired in my L&L electric kiln(oxidation). Nice maroon/burgungy. Sam
Julia M. Townsend on fri 21 feb 97
At 07:07 AM 2/20/97 EST, you wrote:
>----------------------------Original message----------------------------
>Sue,
>
>I suggest you order a mason stain color chart,
>
>Carl in Phillips
>
Ordering this color chart should be real easy as they have a website:
www.ceramics.com/mason/
Kathryn & Stuart Fields on sat 31 jan 04
>Also, keep in mind how stuff is leached. In fact, look at the home test. A
>fairly strong acid, like vinegar, sits in the thing for three days. The
>likelihood of any one ingesting any amount of harmful stuff off a platter
is
>miniscule.
>Paul Lewing, Seattle
Would you complete the explanation of the "home test", please?
Also, according to one long time potter, lead will be burnt out of anything
fired to ^10. What is your opinion or is there a factual answer to this?
Kathy Fields, Inyokern
Earl Brunner on sat 31 jan 04
The assumption I think that lead "burns out" at cone 10 I think comes
from a hazy understanding (or misunderstanding) of the volatilization
point of lead and the variables involved. To blindly base studio
behavior on this assumption could be harmful.
What Frank Hamer says in "The Potter's Dictionary" is that lead oxide in
some forms is "stable" (and that is the key word) up to 2192F. That's
cone 6 and only about 170F below cone 10. We could infer then that
AFTER 2192 it becomes unstable. I would like to see the documentation
that shows lead being totally gone by cone 10. All of those dispersed
molecules have to be able to migrate to the surface of the glaze and
enter the atmosphere of the kiln. Which of coarse then brings up the
added question of where do they go? They are not annihilated, they go
somewhere.
Too many variables, I wouldn't stake my life and health on it.
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of Kathryn &
Stuart Fields
Sent: Saturday, January 31, 2004 7:38 AM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: Mason stains and slips
>Also, keep in mind how stuff is leached. In fact, look at the home
test. A
>fairly strong acid, like vinegar, sits in the thing for three days. The
>likelihood of any one ingesting any amount of harmful stuff off a
platter
is
>miniscule.
>Paul Lewing, Seattle
Would you complete the explanation of the "home test", please?
Also, according to one long time potter, lead will be burnt out of
anything
fired to ^10. What is your opinion or is there a factual answer to
this?
Kathy Fields, Inyokern
Ron Roy on mon 2 feb 04
Lead starts to volitize well before cone 6 - especially if there is any
reduction - the reason it is not used in glazes above cone 6 is that so
much is lost it becomes ineffectual as a flux.
Kiln shelves, pots, kiln furniture and brickes are coated as the lead
condences out during cooling.
RR
>The assumption I think that lead "burns out" at cone 10 I think comes
>from a hazy understanding (or misunderstanding) of the volatilization
>point of lead and the variables involved. To blindly base studio
>behavior on this assumption could be harmful.
>
>What Frank Hamer says in "The Potter's Dictionary" is that lead oxide in
>some forms is "stable" (and that is the key word) up to 2192F. That's
>cone 6 and only about 170F below cone 10. We could infer then that
>AFTER 2192 it becomes unstable. I would like to see the documentation
>that shows lead being totally gone by cone 10. All of those dispersed
>molecules have to be able to migrate to the surface of the glaze and
>enter the atmosphere of the kiln. Which of coarse then brings up the
>added question of where do they go? They are not annihilated, they go
>somewhere.
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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