Megan Ratchford on sat 19 oct 02
Chris,
Burnt Umber plus a smidge of Manganese. Don't really know the
percentages. Laguna has a clay called Dark Brown, cone 10, black/brown,
lovely to work with. Clay Art Center in Tacoma has a black body too.
Megan
In sunny and cool Denver, Colorado fresh from an INCREDIBLE workshop by
Allegheny Meadows.
----- Original Message -----
From: "Chris Clyburn"
To:
Sent: Saturday, October 19, 2002 11:41 AM
Subject: Black Clay body
> Does anyone have any suggestions on how to get a truly black clay body
> using oxides or can suggest a stain? I've tried mangane oxide but all I
> get is a charcoal gray or a true black that bloats so bad it sticks to the
> shelf above it and all the nearby pots. I almost always fire ^10 reduction
> in a gas kiln with the occassional ^10 oxidation in the electric. I know I
> can do a black firing to get a good black, but I want to do a balck and
> white agate ware piece so that technique will not work. Any suggestions
> would be great.
>
> Chris Clyburn
> Back in the saddle again with a _flood_ of ideas :-)
>
>
____________________________________________________________________________
__
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
melpots@pclink.com.
Chris Clyburn on sat 19 oct 02
Does anyone have any suggestions on how to get a truly black clay body
using oxides or can suggest a stain? I've tried mangane oxide but all I
get is a charcoal gray or a true black that bloats so bad it sticks to the
shelf above it and all the nearby pots. I almost always fire ^10 reduction
in a gas kiln with the occassional ^10 oxidation in the electric. I know I
can do a black firing to get a good black, but I want to do a balck and
white agate ware piece so that technique will not work. Any suggestions
would be great.
Chris Clyburn
Back in the saddle again with a _flood_ of ideas :-)
Catherine White on sat 19 oct 02
Would you consider buying the black clay? Aardvark carries a Black
Mountain ^10 that is black. It comes with or without heavy grog. I found at
least three clay places that carried it or would order it for me. I used
the heavily grogged one. Here at AZ University, one of the ceramics courses
used the regular one. They threw and trimmed/finished it. Lovely ware.
Black. And this was only at the bisqued stage. The prof teaching the course
said he and the students love it.
Catherine in Yuma, AZ
Two ancient electric kilns. Both outside.
It never rains here at the Mexican border.
One partner, one kid, three cats. All inside.
----- Original Message -----
Subject: Black Clay body
> Does anyone have any suggestions on how to get a truly black clay body
> using oxides or can suggest a stain?
chris clarke on sat 19 oct 02
chris,
I used a black stoneware from kickwheel pottery in georgia. However it's
cone6. But it was a kickin' clay and they have a match white clay to do
just what you're talking about. It was called black raven. Loved it.
chris
temecula, california
chris@ccpots.com
http://www.ccpots.com
Ababi on sun 20 oct 02
I add to Laguna's calico as dried 5% black iron oxide and 0.2 manganese dioxide, You
can see it in the last pmi or longer in my site:
http://members4.clubphoto.com/ababi306910/912566/
One JPG
http://members4.clubphoto.com/_cgi-bin/getImage.pl?imgID=10580271-53da&trans=
Second JPG]
http://members4.clubphoto.com/_cgi-bin/getImage.pl?imgID=12514163-772e&trans=
It takes long time to download because of the many pictures
By the way, I try these day to change the recipes into easier to reach materials.
Ababi
---------- Original Message ----------
>Does anyone have any suggestions on how to get a truly black clay body
>using oxides or can suggest a stain? I've tried mangane oxide but all I
>get is a charcoal gray or a true black that bloats so bad it sticks to the
>shelf above it and all the nearby pots. I almost always fire ^10 reduction
>in a gas kiln with the occassional ^10 oxidation in the electric. I know I
>can do a black firing to get a good black, but I want to do a balck and
>white agate ware piece so that technique will not work. Any suggestions
>would be great.
>Chris Clyburn
>Back in the saddle again with a _flood_ of ideas :-)
>______________________________________________________________________________
>Send postings to clayart@lsv.ceramics.org
>You may look at the archives for the list or change your subscription
>settings from http://www.ceramics.org/clayart/
>Moderator of the list is Mel Jacobson who may be reached at melpots@pclink.com.
Chris Clyburn on sun 20 oct 02
On Sat, 19 Oct 2002 14:16:00 -0700, Catherine White
wrote:
> Would you consider buying the black clay? Aardvark carries a Black
>Mountain ^10 that is black. It comes with or without heavy grog. I found
at
>least three clay places that carried it or would order it for me.
I am not adverse to buying it. I had heard of Black Mountain before, but I
cannot find a supplier I can order from. Advark has no distributors in
Oklahoma that I can find, and I can't find a web source I can order from.
Any suggestions?
Chris Clyburn
Who is about to try and make a breaking glaze using rare earth
oxides...should be purty LOL
Snail Scott on sun 20 oct 02
At 01:41 PM 10/19/02 -0400, you wrote:
>Does anyone have any suggestions on how to get a truly black clay body
>using oxides or can suggest a stain? I've tried mangane oxide but all I
>get is a charcoal gray...
I've never seen a really black clay
body that didn't involve cobalt in
addition to (usually) manganese &/or
iron. The cobalt seems necessary to
push it that last bit past brown into
true black. It gets expensive as a
body stain, though! Is a black surface
coating (slip/engobe) not an option?
-Snail
Ellie Blair on wed 9 apr 08
I have been trying to get a good black clay body. I do crystalline glazes =
and want to have a black background against my crystals. I have tried the =
mason stains, one with cobalt and one without. I want to apply this stain=
before it is bisque fired. If anyone has an idea it would be great.Ellie =
BlairBlair PotteryLawrence, Kansas 66047=
miriam on wed 9 apr 08
Are you doing ^10 or????
miriam
----- Original Message -----
From: "Ellie Blair"
To:
Sent: Wednesday, April 09, 2008 4:08 PM
Subject: black clay body
I have been trying to get a good black clay body. I do crystalline glazes
and want to have a black background against my crystals. I have tried the
mason stains, one with cobalt and one without. I want to apply this stain
before it is bisque fired. If anyone has an idea it would be great.Ellie
BlairBlair PotteryLawrence, Kansas 66047
______________________________________________________________________________
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You may look at the archives for the list, post messages, change your
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Ellie Blair on wed 9 apr 08
I am doing cone 9 & 10.Ellie BlairBlair PotteryLawrence, Kansas 66047> Date=
: Wed, 9 Apr 2008 18:22:40 -0400> From: mshelomith@TAMPABAY.RR.COM> Subject=
: Re: black clay body> To: CLAYART@LSV.CERAMICS.ORG> > Are you doing ^10 or=
????> > miriam> ----- Original Message -----> From: "Ellie Blair" 3@MSN.COM>> To: > Sent: Wednesday, April 09, 2008=
4:08 PM> Subject: black clay body> > > I have been trying to get a good bl=
ack clay body. I do crystalline glazes> and want to have a black background=
against my crystals. I have tried the> mason stains, one with cobalt and o=
ne without. I want to apply this stain> before it is bisque fired. If anyon=
e has an idea it would be great.Ellie> BlairBlair PotteryLawrence, Kansas 6=
6047> _____________________________________________________________________=
_________> Clayart members may send postings to: clayart@lsv.ceramics.org> =
> You may look at the archives for the list, post messages, change your> su=
bscription settings or unsubscribe/leave the list here:> http://www.acers.o=
rg/cic/clayart/> > Moderator of the list is Mel Jacobson who may be reached=
at> melpots2@visi.com> > _________________________________________________=
_____________________________> Clayart members may send postings to: clayar=
t@lsv.ceramics.org> > You may look at the archives for the list, post messa=
ges, change your> subscription settings or unsubscribe/leave the list here:=
http://www.acers.org/cic/clayart/> > Moderator of the list is Mel Jacobson=
who may be reached at melpots2@visi.com=
Melissa Schooley on wed 9 apr 08
Hi Ellie;
Seattle Pottery Supply has a black claybody that's actually black, not a dark chocolate brown like some others I have tried. It is called Midnight Black, cone 04 - cone 5 and it get's darker the higher you fire it.
Melissa Schooley
Raging Bowl Pottery
www.ragingbowlpottery.com
Handmade Porcelain Celebrating the Art of Fine Craft
-------- Original Message --------
Subject: black clay body
From: Ellie Blair <blairea53@MSN.COM>
Date: Wed, April 09, 2008 1:08 pm
To: CLAYART@LSV.CERAMICS.ORG
I have been trying to get a good black clay body. I do crystalline glazes and want to have a black background against my crystals. I have tried the mason stains, one with cobalt and one without. I want to apply this stain before it is bisque fired. If anyone has an idea it would be great.Ellie BlairBlair PotteryLawrence, Kansas 66047
______________________________________________________________________________
Clayart members may send postings to: clayart@lsv.ceramics.org
You may look at the archives for the list, post messages, change your
subscription settings or unsubscribe/leave the list here: http://www.acers.org/cic/clayart/
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Steve Mills on thu 10 apr 08
Dear Ellie,
I recommend you apply a black slip in the leather hard stage; this would give you a strong even coating without brush or sponge marks.
Steve
Bath
UK
Ellie Blair wrote:
I have been trying to get a good black clay body. I do crystalline glazes and want to have a black background against my crystals. I have tried the mason stains, one with cobalt and one without. I want to apply this stain before it is bisque fired. If anyone has an idea it would be great.Ellie BlairBlair PotteryLawrence, Kansas 66047
______________________________________________________________________________
Clayart members may send postings to: clayart@lsv.ceramics.org
You may look at the archives for the list, post messages, change your
subscription settings or unsubscribe/leave the list here: http://www.acers.org/cic/clayart/
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miriam on thu 10 apr 08
Do not know of a black body that goes up to ^10... The addition of oxide
needed to turn the clay black lowers the temp of vitrification... If you
think that the crystalline glazes run at ^9-10... Your black clay body
would be a puddle in the kiln! miriam
----- Original Message -----
From: "Ellie Blair"
To:
Sent: Wednesday, April 09, 2008 7:54 PM
Subject: Re: black clay body
I am doing cone 9 & 10.Ellie BlairBlair PotteryLawrence, Kansas 66047> Date:
Wed, 9 Apr 2008 18:22:40 -0400> From: mshelomith@TAMPABAY.RR.COM> Subject:
Re: black clay body> To: CLAYART@LSV.CERAMICS.ORG> > Are you doing ^10
or????> > miriam> ----- Original Message -----> From: "Ellie Blair"
> To: > Sent: Wednesday, April
09, 2008 4:08 PM> Subject: black clay body> > > I have been trying to get a
good black clay body. I do crystalline glazes> and want to have a black
background against my crystals. I have tried the> mason stains, one with
cobalt and one without. I want to apply this stain> before it is bisque
fired. If anyone has an idea it would be great.Ellie> BlairBlair
PotteryLawrence, Kansas 66047>
______________________________________________________________________________>
Clayart members may send postings to: clayart@lsv.ceramics.org> > You may
look at the archives for the list, post messages, change your> subscription
settings or unsubscribe/leave the list here:>
http://www.acers.org/cic/clayart/> > Moderator of the list is Mel Jacobson
who may be reached at> melpots2@visi.com> >
______________________________________________________________________________>
Clayart members may send postings to: clayart@lsv.ceramics.org> > You may
look at the archives for the list, post messages, change your> subscription
settings or unsubscribe/leave the list here:
http://www.acers.org/cic/clayart/> > Moderator of the list is Mel Jacobson
who may be reached at melpots2@visi.com
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Lee on thu 10 apr 08
On Thu, Apr 10, 2008 at 3:42 AM, Steve Mills
wrote:
> Dear Ellie,
>
> I recommend you apply a black slip in the leather hard stage; this would give you a strong even
>coating without brush or sponge marks.
Steve,
The first yunomi I made during my apprenticeship were with
Mashiko light colored nami clay, dipped in ocher slip at leather hard.
It made a nice smooth surface. We also dipped white slip for the
aka (red) clay yunomi that had white circles in the jomon, so that it
made a smooth medallion.
One of the great things about the ocher slipping, was
that if you trimmed any with the bottom too thin, they would collapse.
That would always crack the shokunin up but it taught you about
proper trimming.
--
Lee, a Mashiko potter in Minneapolis
http://mashikopots.blogspot.com/
"All that is necessary for evil to succeed is that good men do
nothing." --Edmund Burke
William & Susan Schran User on thu 10 apr 08
On 4/9/08 4:08 PM, "Ellie Blair" wrote:
> I have been trying to get a good black clay body. I do crystalline glazes and
> want to have a black background against my crystals. I have tried the mason
> stains, one with cobalt and one without. I want to apply this stain before
> it is bisque fired. If anyone has an idea it would be great.Ellie BlairBlair
Ellie,
Search on the crystalline forum, I posted test results/images quite some
time back, last fall.
Did some tests of different black Mason stains mixed with slip made from my
clay body.
You'll get blue crystals from those containing cobalt.
Stay away from stains containing chromium.
Bill
--
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com
Fred Parker on thu 10 apr 08
Hi Ellie:
I wasn't sure from your post if you wanted to find a commercial black body
or mix your own -- or what cone. For what it's worth I've tried something
called "Cassius Basaltic" which is a very black body. Aside from its pun-
soaked name, it fires nicely as long as you don't overfire. Overfired,
it's loaded with blisters and blebs. You have to do some experimenting
with glazes for it. This is one case where the body has a HUGE effect on
the glaze. Let me know if you want more info.
Fred Parker
On Wed, 9 Apr 2008 15:08:20 -0500, Ellie Blair wrote:
>I have been trying to get a good black clay body. I do crystalline
glazes and want to have a black background against my crystals. I have
tried the mason stains, one with cobalt and one without. I want to apply
this stain before it is bisque fired. If anyone has an idea it would be
great.Ellie BlairBlair PotteryLawrence, Kansas 66047
>__________________________________________________________________________
____
>Clayart members may send postings to: clayart@lsv.ceramics.org
>
>You may look at the archives for the list, post messages, change your
>subscription settings or unsubscribe/leave the list here:
http://www.acers.org/cic/clayart/
>
>Moderator of the list is Mel Jacobson who may be reached at
melpots2@visi.com
Dale Neese on thu 10 apr 08
I've been satisified using Aardvark Clay's "Black Mountain" cone 10 clay.
Aardvark also makes "Jamaica Blend" that is a blackish brown, smoother
claybody than Black Mountain. I would caution a user of Black Mountain not
to start body reduction earlier than 09 because of possible bloating
problems and fire past cone 10 since the body tends to slump some.
Dale Tex
"across the alley from the Alamo"
San Antonio, Texas USA
http://www.daleneese.com
Steve Slatin on thu 10 apr 08
Fred --
Yes, Cassius is a wonderful clay ... it stains every surface
it touches, it requires a heavy studio clean-up (or change-out
of work surfaces) before returning to any other clay, and it
doesn't mix well with some other clays.
OTOH, if you put John and Ron's Raspberry red glaze
over it, it comes out sparkly and wonderful.
AFAIK, it doesn't fire well over ^6 or maybe 7.
Best -- Steve Slatin
Fred Parker wrote:
Hi Ellie:
I wasn't sure from your post if you wanted to find a commercial black body
or mix your own -- or what cone. For what it's worth I've tried something
called "Cassius Basaltic" which is a very black body. Aside from its pun-
soaked name, it fires nicely as long as you don't overfire. Overfired,
it's loaded with blisters and blebs. You have to do some experimenting
with glazes for it. This is one case where the body has a HUGE effect on
the glaze. Let me know if you want more info.
Fred Parker
__________________________________________________
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William & Susan Schran User on thu 10 apr 08
On 4/10/08 10:48 AM, "Fred Parker" wrote:
> For what it's worth I've tried something
> called "Cassius Basaltic" which is a very black body. Aside from its pun-
> soaked name, it fires nicely as long as you don't overfire. Overfired,
> it's loaded with blisters and blebs. You have to do some experimenting
> with glazes for it. This is one case where the body has a HUGE effect on
> the glaze. Let me know if you want more info.
Fred,
I'd be interested in learning more about this "Cassius Basaltic" clay...
Bill
--
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com
Lili Krakowski on thu 10 apr 08
DON'T!
There still are black clay recipes around. Ignore them. They are full of
manganese dioxide, whose fumes (from firing) probably are responsible for
several deaths in the clay community. David Shaner is a well known case
(though I do not know
if he used manganese in his clay, or "just" his glazes).
Leaving aside that, as Miriam said, at c.10 black body probably would melt
into a puddle, there is something else to consider when dying a body. That
is a lot more colorant is needed in tinting a body than tinting a slip or
glaze.
So it is a costly thing, very costly.
Heed the advice to use a slip.
As to sources: Prof Schran had a great article on Cone 6 crystal glazes
Pottery Making Illustrated Sept/Oct 2007p 31-34
With all good wishes
The Gorilla who does Lili's typing
Bill Merrill on thu 10 apr 08
Dave Shaner died from Lou Gerhigs disease. He was tested for manganese
poisoning and was found to have 3-4 times the manganese in his system as
you or I. He was treated by chelation and much of the manganese was
removed from his system. He used the "Maria" glaze on hand built pots
only and he was careful about handling all his materials. Edouard
Bastarache can tell you more about manganese poisoning...Edouard lets
hear from you about manganese again!!! Dave did not use manganese in
his clay Bodies. You really don't need manganese in a body to make it
black, but you do need metallic oxides to make it black. Ken Ferguson
used an extremely dark clay body, nearly black. Pete Pinnell formulated
that body for Ken. Maybe Pete can offer some suggestions anout "black".
If too much metallic oxide is used in the body, that can cause problems.
I have used manganese for 40 years and used it in saturated manganese
glazes. I have always been careful with all ceramics materials and have
no health issues from ceramic materials.=20
=20
Bill Merrill
=20
=20
=20
=20
Edouard Bastarache Inc. [edouardb@SOREL-TRACY.QC.CA]
=20
=20
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of Lili
Krakowski
Sent: Thursday, April 10, 2008 1:17 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Black clay body
=20
DON'T!
=20
There still are black clay recipes around. Ignore them. They are full
of
manganese dioxide, whose fumes (from firing) probably are responsible
for
several deaths in the clay community. David Shaner is a well known case
(though I do not know
if he used manganese in his clay, or "just" his glazes).
=20
Leaving aside that, as Miriam said, at c.10 black body probably would
melt
into a puddle, there is something else to consider when dying a body.
That
is a lot more colorant is needed in tinting a body than tinting a slip
or
glaze.
So it is a costly thing, very costly.
=20
Heed the advice to use a slip.
=20
As to sources: Prof Schran had a great article on Cone 6 crystal glazes
Pottery Making Illustrated Sept/Oct 2007p 31-34
=20
With all good wishes
=20
The Gorilla who does Lili's typing
=20
________________________________________________________________________
______
Clayart members may send postings to: clayart@lsv.ceramics.org
=20
You may look at the archives for the list, post messages, change your
subscription settings or unsubscribe/leave the list here:
http://www.acers.org/cic/clayart/
=20
Moderator of the list is Mel Jacobson who may be reached at
melpots2@visi.com
steve graber on thu 10 apr 08
around here i don't think i've seen that clay, but a Black Mountain is a very dark black basalt claybody.
i love it! it has an extremely great feel, throws well, hand builds well, fires very black-brown at cone 10 reduction.
i often fire these pieces naked, no glaze, just shape and my texture.
laguna's cone 10 glaze turquoize matt works well on this black mountain claybody.
and i like some where the glaze is applied and slightly rubbed off to get further contrast.
tenmoku's come out VERY rich in deep black, from the claybody being so black.
see ya
Steve Graber, Graber's Pottery, Inc
Claremont, California USA
The Steve Tool - for awesum texture on pots!
www.graberspottery.com steve@graberspottery.com
----- Original Message ----
From: William & Susan Schran User
To: CLAYART@LSV.CERAMICS.ORG
Sent: Thursday, April 10, 2008 9:28:33 AM
Subject: Re: black clay body
On 4/10/08 10:48 AM, "Fred Parker" wrote:
> For what it's worth I've tried something
> called "Cassius Basaltic" which is a very black body. Aside from its pun-
> soaked name, it fires nicely as long as you don't overfire. Overfired,
> it's loaded with blisters and blebs. You have to do some experimenting
> with glazes for it. This is one case where the body has a HUGE effect on
> the glaze. Let me know if you want more info.
Fred,
I'd be interested in learning more about this "Cassius Basaltic" clay...
Bill
--
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com
______________________________________________________________________________
Clayart members may send postings to: clayart@lsv.ceramics.org
You may look at the archives for the list, post messages, change your
subscription settings or unsubscribe/leave the list here: http://www.acers.org/cic/clayart/
Moderator of the list is Mel Jacobson who may be reached at melpots2@visi.com
__________________________________________________
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Edouard Bastarache Inc. on fri 11 apr 08
Bill,
I will make a few comments :
1-Blood manganese is not a Biological Esposure
Index (B.E.I.)
A B.E.I. relates directly to the severity of
exposure of the
patient. It means if you do no have the means to
measure the
exposure, the B.E.I. is sufficient. This the case
for lead not
manganese.
2-Parkinson-like disease is the only clinical
entity generally
accepted and caused by over-exposure to manganese.
3-In Parkinson's, tremors appear at rest while in
Parkinson-
like they are intentional.
4-Often times the only clue to diagnosis is a
history of exposure
to manganese.
5-Manganese fumes appear 5 times more toxic than
the dust.
Fumes = 1 mg/m³
Dust and Compounds = 5 mg/m³
Gis revido,
(A la revoyure)
Edouard Bastarache
Spertesperantisto
Sorel-Tracy
Quebec
http://www.pshcanada.com/Toxicology.htm
http://www.flickr.com/photos/30058682@N00/
http://www.flickr.com/photos/potier/20321056/
http://perso.orange.fr/smart2000/livres.htm
http://myblogsmesblogs.blogspot.com/
----- Original Message -----
From: "Bill Merrill"
To:
Sent: Thursday, April 10, 2008 7:04 PM
Subject: Re: Black clay body
Dave Shaner died from Lou Gerhigs disease. He was
tested for manganese
poisoning and was found to have 3-4 times the
manganese in his system as
you or I. He was treated by chelation and much of
the manganese was
removed from his system. He used the "Maria" glaze
on hand built pots
only and he was careful about handling all his
materials. Edouard
Bastarache can tell you more about manganese
poisoning...Edouard lets
hear from you about manganese again!!! Dave did
not use manganese in
his clay Bodies. You really don't need manganese
in a body to make it
black, but you do need metallic oxides to make it
black. Ken Ferguson
used an extremely dark clay body, nearly black.
Pete Pinnell formulated
that body for Ken. Maybe Pete can offer some
suggestions anout "black".
If too much metallic oxide is used in the body,
that can cause problems.
I have used manganese for 40 years and used it in
saturated manganese
glazes. I have always been careful with all
ceramics materials and have
no health issues from ceramic materials.
Bill Merrill
Edouard Bastarache Inc.
[edouardb@SOREL-TRACY.QC.CA]
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On
Behalf Of Lili
Krakowski
Sent: Thursday, April 10, 2008 1:17 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Black clay body
DON'T!
There still are black clay recipes around. Ignore
them. They are full
of
manganese dioxide, whose fumes (from firing)
probably are responsible
for
several deaths in the clay community. David
Shaner is a well known case
(though I do not know
if he used manganese in his clay, or "just" his
glazes).
Leaving aside that, as Miriam said, at c.10 black
body probably would
melt
into a puddle, there is something else to consider
when dying a body.
That
is a lot more colorant is needed in tinting a body
than tinting a slip
or
glaze.
So it is a costly thing, very costly.
Heed the advice to use a slip.
As to sources: Prof Schran had a great article on
Cone 6 crystal glazes
Pottery Making Illustrated Sept/Oct 2007p 31-34
With all good wishes
The Gorilla who does Lili's typing
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Kristina Pell on fri 11 apr 08
I've used Cassius Black a lot and I'm pretty sure there's manganese in it but have never been able to get a positive answer about that. Our local ceramic supply store doesn't seem to know and it would seem to me that there should be some sort of warning if there is. It seems I tried getting that info from Aardvark years ago and had no luck or maybe I just forgot. It's been a while. In any case, I use gloves when I work with it and try to keep the dust down. Some of my students were working with Aardvark's Black Mountain clay and I suggested they use gloves until I could find out if it has manganese in it. Anyone know about that one?
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Peter Cunicelli on fri 11 apr 08
Hi Kristina,
I know for a fact that Cassius Basalt does have manganese in it. I stopped
using it because my kiln is in a public area of my studio building. I
didn't realize that the fumes were poisonous as well.
I have a lot for reclaim right now and if I use it, I will wear gloves.
That kind of kills it for me. Part of my joy of working with clay is
actually touching it.
I don't know about the other black clay bodies others have mentioned.
P
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www.petercunicelli.com
-----Original Message-----
From: owner-clayart@LSV.CERAMICS.ORG [mailto:owner-clayart@LSV.CERAMICS.ORG]
On Behalf Of Kristina Pell
Sent: Friday, April 11, 2008 9:58 AM
To: Clayart
Subject: Re: black clay body
I've used Cassius Black a lot and I'm pretty sure there's manganese in it
but have never been able to get a positive answer about that. Our local
ceramic supply store doesn't seem to know and it would seem to me that there
should be some sort of warning if there is. It seems I tried getting that
info from Aardvark years ago and had no luck or maybe I just forgot. It's
been a while. In any case, I use gloves when I work with it and try to keep
the dust down. Some of my students were working with Aardvark's Black
Mountain clay and I suggested they use gloves until I could find out if it
has manganese in it. Anyone know about that one?
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Fredrick Paget on fri 11 apr 08
Ask them for the MSDS (Material Saftey Data Sheet). They have to give
you that if you ask. It's the law.
I've used Cassius Black a lot and I'm pretty sure there's manganese
in it but have never been able to get a positive answer about that.
--
Fred Paget
Twin Dragon Studio
Mill Valley, CA, USA
fredrick@well.com
Charter Member Potters Council
jonathan byler on fri 11 apr 08
you should be able to get an MSDS sheet from the manufacturer. they
are required by law to have them and provide them if they use
anything even remotely toxic. I'm not sure, but they may even be
required by law to have them even if there is nothing toxic, just to
prove that to the end user. Just because we are a bunch of silly
"artists" doesn't mean we shouldn't have access to all the most up
to date info about the materials we use. We are technically very
small scale industrial units, some larger than others, and if you do
this stuff every day, or even every week, would be wise to take all
the precautions that industry is required to do. I know dealing with
health and safety and environmental isssues can be a pain, but
chronic illnesses and cleaning up toxic waste from your property are
even more of a pain. Get those MSDS sheets!!!
jon
jon byler
3-D Building Coordinator
Art Department
Auburn University, AL 36849
On Apr 11, 2008, at 8:58 AM, Kristina Pell wrote:
> I've used Cassius Black a lot and I'm pretty sure there's
> manganese in it but have never been able to get a positive answer
> about that. Our local ceramic supply store doesn't seem to know and
> it would seem to me that there should be some sort of warning if
> there is. It seems I tried getting that info from Aardvark years
> ago and had no luck or maybe I just forgot. It's been a while. In
> any case, I use gloves when I work with it and try to keep the dust
> down. Some of my students were working with Aardvark's Black
> Mountain clay and I suggested they use gloves until I could find
> out if it has manganese in it. Anyone know about that one?
>
> __________________________________________________
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>
> You may look at the archives for the list, post messages, change your
> subscription settings or unsubscribe/leave the list here: http://
> www.acers.org/cic/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
> melpots2@visi.com
Fred Parker on fri 11 apr 08
Hey Steve:
Thanks for the comments re Cassius. SO far I seem to overfired much of
it, and in overfiring every glaze I have used (including around a dozen
tests) came out burned to a cinder. I do have one yunomi (my personal
favorite) that came out good. It is partially glazed in a weird white
that picked up some strange brown patterning. Damn nearly has made a tea
drinker of me...
Fred
On Thu, 10 Apr 2008 09:27:49 -0700, Steve Slatin
wrote:
>Fred --
>
> Yes, Cassius is a wonderful clay ... it stains every surface
> it touches, it requires a heavy studio clean-up (or change-out
> of work surfaces) before returning to any other clay, and it
> doesn't mix well with some other clays.
>
> OTOH, if you put John and Ron's Raspberry red glaze
> over it, it comes out sparkly and wonderful.
>
> AFAIK, it doesn't fire well over ^6 or maybe 7.
>
> Best -- Steve Slatin
>
>Fred Parker wrote:
> Hi Ellie:
>
>I wasn't sure from your post if you wanted to find a commercial black body
>or mix your own -- or what cone. For what it's worth I've tried something
>called "Cassius Basaltic" which is a very black body. Aside from its pun-
>soaked name, it fires nicely as long as you don't overfire. Overfired,
>it's loaded with blisters and blebs. You have to do some experimenting
>with glazes for it. This is one case where the body has a HUGE effect on
>the glaze. Let me know if you want more info.
>
>Fred Parker
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Snail Scott on sat 12 apr 08
>
> Date: Fri, 11 Apr 2008 06:58:15 -0700
> From: Kristina Pell > I've used Cassius Black a lot...I suggested they use gloves until I
> could find out if it has manganese in it...
It seems pretty clear at this point that there is no
significant hazard from manganese contact with
the skin. It's inhaling the firing fumes that is bad,
so just stay away while the kiln is firing, and for
as long as any residual firing fumes may remain
in the space. Ventilation is a good idea, anyway.
A material that's very toxic through one route
can be quite innocuous through another.
(Case in point: water...fatal when inhaled!)
-Snail
jonathan byler on sun 13 apr 08
I would like to add, that clay dust in general, is something worth
keeping out of the studio as much as possible. I personally know at
least one person who is not so old (late 30's) who, through imprudent
judgement in his youth, did not take precaution against air-borne
dust in the ceramics studio. Said person is still with us, but finds
it, for health reasons, imprudent to continue further working with
clay. Very sad, he was *extremely* talented.
Silicosis is usually such a stealthy, quiet, and slow killer, that
too many people just say, "poo-poo" and ignore all good industrial
hygiene when it comes to clay. It seems very hard to get the
seriousness of healthy work practices into peoples heads, yet at the
same time, you have the others who see anything that is slightly
toxic, and want to ban everything immediately. Knowledge, balance,
and good sense, appear to be the keys to using all of these, things,
including the manganese bearing clay safely.
jon byler
3-D Building Coordinator
Art Department
Auburn University, AL 36849
On Apr 13, 2008, at 10:30 AM, Vince Pitelka wrote:
> Snail wrote:
> "It seems pretty clear at this point that there is no
> significant hazard from manganese contact with
> the skin. It's inhaling the firing fumes that is bad,
> so just stay away while the kiln is firing, and for
> as long as any residual firing fumes may remain
> in the space. Ventilation is a good idea, anyway.
> A material that's very toxic through one route
> can be quite innocuous through another."
>
> Snail is right. The standard coloring oxides we use in the studio
> (iron
> oxides, copper carbonate and oxides, chrome oxide, rutile, titanium
> dioxide,
> cobalt carbonate and oxide, and manganese dioxide) are insoluble
> and of no
> danger in skin contact. Our resident Clayart toxicologist Edouard
> Bastarache has confirmed this. Some people experience skin
> irritation from
> fine particles in the pores, and in those cases gloves would
> certainly be in
> order, especially if there are any open sores. Otherwise, there is no
> danger in manipulating clays and slips colored with these standard
> oxides.
>
> It should go without saying that you should always protect yourself
> from the
> dust of these oxides by wearing a respirator when handling the dry
> oxides,
> and none of these oxides should come in contact with the mucous
> membranes.
> As Snail says, a primary danger is in the fumes produced during
> firing, and
> thus proper kiln ventilation is essential.
> - Vince
>
> Vince Pitelka
> Appalachian Center for Craft
> Tennessee Tech University
> vpitelka@dtccom.net; wpitelka@tntech.edu
> http://iweb.tntech.edu/wpitelka
>
> ______________________________________________________________________
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> Clayart members may send postings to: clayart@lsv.ceramics.org
>
> You may look at the archives for the list, post messages, change your
> subscription settings or unsubscribe/leave the list here: http://
> www.acers.org/cic/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
> melpots2@visi.com
Kristina Pell on sun 13 apr 08
>It seems pretty clear at this point that there is no
>significant hazard from manganese contact with
>the skin.
Well, maybe I guess I assume everyone has the same nervous habit of gnawing
on cuticles. That's why I wear gloves, sometimes my cuticles get kinda raw.
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Vince Pitelka on sun 13 apr 08
Snail wrote:
"It seems pretty clear at this point that there is no
significant hazard from manganese contact with
the skin. It's inhaling the firing fumes that is bad,
so just stay away while the kiln is firing, and for
as long as any residual firing fumes may remain
in the space. Ventilation is a good idea, anyway.
A material that's very toxic through one route
can be quite innocuous through another."
Snail is right. The standard coloring oxides we use in the studio (iron
oxides, copper carbonate and oxides, chrome oxide, rutile, titanium dioxide,
cobalt carbonate and oxide, and manganese dioxide) are insoluble and of no
danger in skin contact. Our resident Clayart toxicologist Edouard
Bastarache has confirmed this. Some people experience skin irritation from
fine particles in the pores, and in those cases gloves would certainly be in
order, especially if there are any open sores. Otherwise, there is no
danger in manipulating clays and slips colored with these standard oxides.
It should go without saying that you should always protect yourself from the
dust of these oxides by wearing a respirator when handling the dry oxides,
and none of these oxides should come in contact with the mucous membranes.
As Snail says, a primary danger is in the fumes produced during firing, and
thus proper kiln ventilation is essential.
- Vince
Vince Pitelka
Appalachian Center for Craft
Tennessee Tech University
vpitelka@dtccom.net; wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka
Ron Roy on thu 17 apr 08
Just in case it is not clear Ellie,
If a clay body has Manganese in it - manganese is toxic - don't breath it
in dust form or fumes from firing it - both can lead to irreversible nerve
damage.
If manganese is in clay the dust from that clay in your studio can become
airborne many ways and can hang in the air for long periods. The fumes from
firing will condense on all surfaces and can become air borne along with
dust.
Many clay companies do not use manganese in clays anymore - just not worth
the risk.
Find out - and get your answer in writing - if there is any powdered
manganese in any dark or black clays from the companies that make them.
RR
>I have been trying to get a good black clay body. I do crystalline glazes
>and want to have a black background against my crystals. I have tried the
>mason stains, one with cobalt and one without. I want to apply this
>stain before it is bisque fired. If anyone has an idea it would be
>great.Ellie BlairBlair PotteryLawrence, Kansas 66047
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>Clayart members may send postings to: clayart@lsv.ceramics.org
>
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Ron Roy
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
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