Lili Krakowski on wed 14 nov 07
Barnard Clay, a.k.a. Blackbird can be replaced by this mixture Ron Roy
posted some time ago.
(My computer crashed taking my recipes with it...but notebooks remain
faithful )
Red Art Clay 56.5
OM4 18
Silica 25.5
Fe2O3 23.5
MnO2 5.5
Lili Krakowski
Be of good courage
Edouard Bastarache Inc. on wed 14 nov 07
Lilli,
don't tell me Ron uses manganese (hehehehe).
Gis la revido,
Edouard Bastarache
Spertesperantisto
Sorel-Tracy
Quebec
http://www.sorel-tracy.qc.ca/~edouardb/Welcome.html
http://perso.orange.fr/smart2000/livres.htm
http://www.pshcanada.com/Toxicology.htm
http://www.ceramique.com/librairie/
http://www.flickr.com/photos/30058682@N00/
http://myblogsmesblogs.blogspot.com/
----- Original Message -----
From: "Lili Krakowski"
To:
Sent: Wednesday, November 14, 2007 4:21 PM
Subject: Barnard Clay substitute
> Barnard Clay, a.k.a. Blackbird can be replaced
> by this mixture Ron Roy
> posted some time ago.
>
> (My computer crashed taking my recipes with
> it...but notebooks remain
> faithful )
>
> Red Art Clay 56.5
> OM4 18
> Silica 25.5
> Fe2O3 23.5
> MnO2 5.5
>
>
> Lili Krakowski
> Be of good courage
>
> ______________________________________________________________________________
> Clayart members may send postings to:
> clayart@lsv.ceramics.org
>
> You may look at the archives for the list, post
> messages, or change your
> subscription settings here:
> http://www.acers.org/cic/clayart/
>
> Moderator of the list is Mel Jacobson who may be
> reached at melpots2@visi.com
>
>
>
> --
> No virus found in this incoming message.
> Checked by AVG Free Edition. Version: 7.5.503 /
> Virus Database: 269.15.31/1130 - Release Date:
> 2007-11-14 09:27
>
>
Jon Pacini on fri 16 nov 07
Greetings All ---Hi Edouard--- you wrote ---don't tell me Ron uses manganese
(hehehehe).
Didn't you know his full name is Ron "devil may care" Roy ?? :-)
Best regards
Jon Pacini
Clay Manager
Laguna Clay Co
Edouard Bastarache Inc. on sat 17 nov 07
Ron,
"What do you tell people about manganese?
RR"
I tell them to read my article posted on the Net.
Gis la revido,
Edouard Bastarache
Spertesperantisto
Sorel-Tracy
Quebec
http://www.sorel-tracy.qc.ca/~edouardb/Welcome.html
http://perso.orange.fr/smart2000/livres.htm
http://www.pshcanada.com/Toxicology.htm
http://www.ceramique.com/librairie/
http://www.flickr.com/photos/30058682@N00/
http://myblogsmesblogs.blogspot.com/
Ron Roy on sat 17 nov 07
Hi Ed,
Used to before I knew better - used a Barnard slip glaze - there is lots of
Manganese in Barnard - thats why it's necessary in a substitute.
I would advise anyone to be very careful about breathing any dust with
manganese in it - or - worse - kiln fumes. There is no doubt about the
toxicity of the material - even by ingestion.
What do you tell people about manganese?
RR
>Lilli,
>
>don't tell me Ron uses manganese (hehehehe).
>
>
>Gis la revido,
>
>Edouard Bastarache
>Spertesperantisto
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Bill Merrill on sun 18 nov 07
Barnard or Blackbird clay has a little manganese in it. The iron
content is about 5 times higher than the manganese. People are being
paranoid about some of these materials. I do not hesitate to use barnard
clay as a stain and will continue to do so. I have used it for 40 years
and as with all finely ground ceramic materials I use them with good
sense. I wear a mask and I do not make cumulus clouds of dust when
mixing glazes. I pour the dry materials into water and mix with an
electric drill with a Jiffy mixer attached. High concentrates of any
metallic oxide may be absorbed into through the skin. If high manganese
glazes are to be used, don't put it an the inside of a functional bowl.
Use tongs to dip, wear gloves. If you use a high manganese glaze, make
sure your kiln is outside or well ventilated.=20
=20
59.74 % SiO2 Barnard clay
10.87 % Al2O3
2.05 % K2O=20
0.12 % Na2O=20
0.75 % MgO=20
0.27 % CaO=20
14.65 % Fe2O3
3.40 % MnO=20
0.67 % TiO2=20
=20
Dave Shaner was said to have died due to manganese poisoning. He had
chelation treatments and found his levels of manganese were higher than
normal. In reality Dave was unfortunate to have Lou Grerigs disease.
In all reality, if one uses materials safely most will be OK to use.
Some of the best glazes that produce beautiful colors are made with
small amounts of manganese. Lucy Rie use a copper/manganese and clay
mix to produce the Faux gold banding on many of her pots. She live a
long productive life.
=20
People have been talking about using iron chloride. In solution or just
touching iron chloride will absorb it into system and breathing the
fumes when fuming pots may even be worse on your health.
=20
Everyone has to make up their own mind about the use of our ceramics
materials from clays to the minerals and oxides we use in the production
of our art. The nice thing is that we can make up our own mind and
listen to science when we are in jeopardy when it comes to our health.
=20
I am not saying you can handle oxides in a haphazard way and be OK with
that. Take precautions with all ceramic materials, but not to the point
of paralyzing your growth in the development of glazes etc. Be Safe!!!
=20
Bill
=20
billm@pcadmin.ctc.edu
=20
=20
=20
=20
=20
=20
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of Ron Roy
Sent: Saturday, November 17, 2007 1:37 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: Barnard Clay substitute
=20
Hi Ed,
=20
Used to before I knew better - used a Barnard slip glaze - there is lots
of
Manganese in Barnard - thats why it's necessary in a substitute.
=20
I would advise anyone to be very careful about breathing any dust with
manganese in it - or - worse - kiln fumes. There is no doubt about the
toxicity of the material - even by ingestion.
=20
What do you tell people about manganese?
=20
RR
=20
=20
=20
>Lilli,
>=20
>don't tell me Ron uses manganese (hehehehe).
>=20
>=20
>Gis la revido,
>=20
>Edouard Bastarache
>Spertesperantisto
=20
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
=20
________________________________________________________________________
______
Clayart members may send postings to: clayart@lsv.ceramics.org
=20
You may look at the archives for the list, post messages, or change your
subscription settings here: http://www.acers.org/cic/clayart/
=20
Moderator of the list is Mel Jacobson who may be reached at
melpots2@visi.com
Dan Semler on sun 18 nov 07
Hi Edouard,
I had a quick poke about in your URLs below but could not find it.
Could you lob us a link to it ?
> Ron,
>
> "What do you tell people about manganese?
> RR"
>
> I tell them to read my article posted on the Net.
Many thanx
D
Edouard Bastarache Inc. on mon 19 nov 07
In French and English on Smarts site :
Gis la revido,
Edouard Bastarache
Spertesperantisto
Sorel-Tracy
Quebec
http://www.sorel-tracy.qc.ca/~edouardb/Welcome.html
http://perso.orange.fr/smart2000/livres.htm
http://www.pshcanada.com/Toxicology.htm
http://www.ceramique.com/librairie/
http://www.flickr.com/photos/30058682@N00/
http://myblogsmesblogs.blogspot.com/
http://pagesperso-orange.fr/smart2000/Manganese.htm
----- Original Message -----
From: "Dan Semler"
To:
Sent: Sunday, November 18, 2007 12:26 PM
Subject: Re: Barnard Clay substitute
> Hi Edouard,
>
> I had a quick poke about in your URLs below
> but could not find it.
> Could you lob us a link to it ?
>
>> Ron,
>>
>> "What do you tell people about manganese?
>> RR"
>>
>> I tell them to read my article posted on the
>> Net.
>
> Many thanx
> D
>
> ______________________________________________________________________________
> Clayart members may send postings to:
> clayart@lsv.ceramics.org
>
> You may look at the archives for the list, post
> messages, or change your
> subscription settings here:
> http://www.acers.org/cic/clayart/
>
> Moderator of the list is Mel Jacobson who may be
> reached at melpots2@visi.com
>
>
>
> --
> No virus found in this incoming message.
> Checked by AVG Free Edition. Version: 7.5.503 /
> Virus Database: 269.16.0/1139 - Release Date:
> 2007-11-19 12:35
>
>
Ron Roy on tue 20 nov 07
Hi Ed,
If the one you are talking about is on the digital fire site - I think it
needs updating.
RR
>Ron,
>
> "What do you tell people about manganese?
> RR"
>
>I tell them to read my article posted on the Net.
>Edouard Bastarache
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Edouard Bastarache Inc. on tue 20 nov 07
Here is the URL.
http://pagesperso-orange.fr/smart2000/Manganese.htm
Gis la revido,
Edouard Bastarache
Spertesperantisto
Sorel-Tracy
Quebec
http://www.sorel-tracy.qc.ca/~edouardb/Welcome.html
http://perso.orange.fr/smart2000/livres.htm
http://www.pshcanada.com/Toxicology.htm
http://www.ceramique.com/librairie/
http://www.flickr.com/photos/30058682@N00/
http://myblogsmesblogs.blogspot.com/
----- Original Message -----
From: "Edouard Bastarache Inc."
To:
Sent: Monday, November 19, 2007 4:49 PM
Subject: Re: Barnard Clay substitute
> In French and English on Smarts site :
> Gis la revido,
>
> Edouard Bastarache
> Spertesperantisto
>
> Sorel-Tracy
> Quebec
> http://www.sorel-tracy.qc.ca/~edouardb/Welcome.html
> http://perso.orange.fr/smart2000/livres.htm
> http://www.pshcanada.com/Toxicology.htm
> http://www.ceramique.com/librairie/
> http://www.flickr.com/photos/30058682@N00/
> http://myblogsmesblogs.blogspot.com/
>
>
>
> http://pagesperso-orange.fr/smart2000/Manganese.htm
>
>
>
> ----- Original Message -----
> From: "Dan Semler"
> To:
> Sent: Sunday, November 18, 2007 12:26 PM
> Subject: Re: Barnard Clay substitute
>
>
>> Hi Edouard,
>>
>> I had a quick poke about in your URLs below
>> but could not find it.
>> Could you lob us a link to it ?
>>
>>> Ron,
>>>
>>> "What do you tell people about manganese?
>>> RR"
>>>
>>> I tell them to read my article posted on the
>>> Net.
>>
>> Many thanx
>> D
>>
>> ______________________________________________________________________________
>> Clayart members may send postings to:
>> clayart@lsv.ceramics.org
>>
>> You may look at the archives for the list, post
>> messages, or change your
>> subscription settings here:
>> http://www.acers.org/cic/clayart/
>>
>> Moderator of the list is Mel Jacobson who may
>> be
>> reached at melpots2@visi.com
>>
>>
>>
>> --
>> No virus found in this incoming message.
>> Checked by AVG Free Edition. Version: 7.5.503 /
>> Virus Database: 269.16.0/1139 - Release Date:
>> 2007-11-19 12:35
>>
>>
>
> ______________________________________________________________________________
> Clayart members may send postings to:
> clayart@lsv.ceramics.org
>
> You may look at the archives for the list, post
> messages, or change your
> subscription settings here:
> http://www.acers.org/cic/clayart/
>
> Moderator of the list is Mel Jacobson who may be
> reached at melpots2@visi.com
>
>
>
> --
> No virus found in this incoming message.
> Checked by AVG Free Edition. Version: 7.5.503 /
> Virus Database: 269.16.0/1139 - Release Date:
> 2007-11-19 12:35
>
>
Edouard Bastarache Inc. on tue 20 nov 07
Ron,
Don't worry about that.
Only 5 % of ingested manganese is absorbed by the gut,
so forget about this route of entry.
Manganese is not regulated for utilitarian wares.
You have to worry about inhaled dusts and fumes,
if you use some sort of ventilation the problem
is not so important, fumes are 5 times more noxious
than dusts; 1 mg/m3 for the fumes and 5 mg/m3 for=20
dusts.
=20
Ventilation is a very important factor.
Read the following text from experts :
"AUTHOR: Bob Hirtle; Kay Teschke; Chris van Netten; Michael Brauer
TITLE: Kiln Emissions and Potters' Exposures
SOURCE: American Industrial Hygiene Association Journal v59 no10 p706-14 =
O '98
The magazine publisher is the copyright holder of this article and it is =
reproduced with
permission. Further reproduction of this article in violation of the =
copyright is prohibited.
ABSTRACT
Some ten thousand British Columbia potters work in small private =
studios, cooperative
facilities, educational institutions, or recreation centers. There has =
been considerable
concern that this diffuse, largely unregulated activity may involve =
exposures to
unacceptable levels of kiln emissions. Pottery kiln emissions were =
measured at 50
sites-10 from each of 5 categories: professional studios, recreation =
centers,
elementary schools, secondary schools, and colleges. Area monitoring was =
done 76 cm
from firing kilns and 1.6 m above the floor to assess breathing zone =
concentrations of
nitrogen dioxide, carbon monoxide, sulfur dioxide, fluorides, aldehydes, =
aluminum,
antimony, arsenic, barium, beryllium, boron, cadmium, chromium, cobalt, =
copper, gold,
iron, lead, lithium, magnesium, manganese, mercury, nickel, selenium, =
silver, vanadium,
and zinc. Personal exposures to the same metals were measured at 24 =
sites. Almost
all measured values were well below permissible concentrations for =
British Columbia
work sites and American Conference of Governmental Industrial Hygienists =
(ACGIH)
threshold limit values (TLVs) with the following two exceptions. A =
single firing duration
(495 minute) acrolein measurement adjacent to an electric kiln (0.109 =
ppm) exceeded
these guidelines. One 15-minute sulfur dioxide measurement collected =
adjacent to a
gas kiln (5.7 ppm) exceeded the ACGIH short-term exposure limit. The =
fact that
concentrations in small, ventilated kiln rooms ranked among the highest =
measured
gives rise to concern that unacceptable levels of contamination may =
exist where small
kiln rooms remain unventilated. Custom designed exhaust hoods and =
industrial heating,
ventilating, and air-conditioning systems were the most effective =
ventilation strategies.
Passive diffusion and wall/window fans were least effective."
Who made the diagnosis on Shaner, we do not know....
Gis la revido,
Edouard Bastarache
Spertesperantisto
Sorel-Tracy
Quebec
http://www.sorel-tracy.qc.ca/~edouardb/Welcome.html
http://perso.orange.fr/smart2000/livres.htm
http://www.pshcanada.com/Toxicology.htm
http://www.ceramique.com/librairie/
http://www.flickr.com/photos/30058682@N00/
http://myblogsmesblogs.blogspot.com/
----- Original Message -----=20
From: "Ron Roy"
To:
Sent: Tuesday, November 20, 2007 2:06 AM
Subject: Re: Barnard Clay substitute
> Hi Ed,
>=20
> If the one you are talking about is on the digital fire site - I think =
it
> needs updating.
>=20
> RR
>=20
>>Ron,
>>
>> "What do you tell people about manganese?
>> RR"
>>
>>I tell them to read my article posted on the Net.
>=20
>>Edouard Bastarache
>=20
> Ron Roy
> RR#4
> 15084 Little Lake Road
> Brighton, Ontario
> Canada
> K0K 1H0
>=20
> =
_________________________________________________________________________=
_____
> Clayart members may send postings to: clayart@lsv.ceramics.org
>=20
> You may look at the archives for the list, post messages, or change =
your
> subscription settings here: http://www.acers.org/cic/clayart/
>=20
> Moderator of the list is Mel Jacobson who may be reached at =
melpots2@visi.com
>=20
>=20
>=20
> --=20
> No virus found in this incoming message.
> Checked by AVG Free Edition.=20
> Version: 7.5.503 / Virus Database: 269.16.0/1139 - Release Date: =
2007-11-19 12:35
>=20
>
Ron Roy on thu 22 nov 07
Hi Bill - I agree with most of what you are saying but there are still
plenty of potters who are unaware of many toxicity issues.
Potters will always choose to use whatever materials they want to use - I
just want them to know which to be careful with.
I think David Shaner was one of the best potters ever - I can't help
thinking that he would still be with us if he had know the dangers of using
a saturated manganese glaze.
RR
>Barnard or Blackbird clay has a little manganese in it. The iron
>content is about 5 times higher than the manganese. People are being
>paranoid about some of these materials. I do not hesitate to use barnard
>clay as a stain and will continue to do so. I have used it for 40 years
>and as with all finely ground ceramic materials I use them with good
>sense. I wear a mask and I do not make cumulus clouds of dust when
>mixing glazes. I pour the dry materials into water and mix with an
>electric drill with a Jiffy mixer attached. High concentrates of any
>metallic oxide may be absorbed into through the skin. If high manganese
>glazes are to be used, don't put it an the inside of a functional bowl.
>Use tongs to dip, wear gloves. If you use a high manganese glaze, make
>sure your kiln is outside or well ventilated.
>
>
>
>59.74 % SiO2 Barnard clay
>10.87 % Al2O3
>2.05 % K2O
>0.12 % Na2O
>0.75 % MgO
>0.27 % CaO
>14.65 % Fe2O3
>3.40 % MnO
>0.67 % TiO2
>
>
>
>Dave Shaner was said to have died due to manganese poisoning. He had
>chelation treatments and found his levels of manganese were higher than
>normal. In reality Dave was unfortunate to have Lou Grerigs disease.
>In all reality, if one uses materials safely most will be OK to use.
>Some of the best glazes that produce beautiful colors are made with
>small amounts of manganese. Lucy Rie use a copper/manganese and clay
>mix to produce the Faux gold banding on many of her pots. She live a
>long productive life.
>
>
>
>People have been talking about using iron chloride. In solution or just
>touching iron chloride will absorb it into system and breathing the
>fumes when fuming pots may even be worse on your health.
>
>
>
>Everyone has to make up their own mind about the use of our ceramics
>materials from clays to the minerals and oxides we use in the production
>of our art. The nice thing is that we can make up our own mind and
>listen to science when we are in jeopardy when it comes to our health.
>
>
>
>I am not saying you can handle oxides in a haphazard way and be OK with
>that. Take precautions with all ceramic materials, but not to the point
>of paralyzing your growth in the development of glazes etc. Be Safe!!!
>
>
>
>Bill
>
>
>
>billm@pcadmin.ctc.edu
>
>
>
>
>
>
>
>
>
>
>
>
>
>-----Original Message-----
>From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of Ron Roy
>Sent: Saturday, November 17, 2007 1:37 PM
>To: CLAYART@LSV.CERAMICS.ORG
>Subject: Re: Barnard Clay substitute
>
>
>
>Hi Ed,
>
>
>
>Used to before I knew better - used a Barnard slip glaze - there is lots
>of
>
>Manganese in Barnard - thats why it's necessary in a substitute.
>
>
>
>I would advise anyone to be very careful about breathing any dust with
>
>manganese in it - or - worse - kiln fumes. There is no doubt about the
>
>toxicity of the material - even by ingestion.
>
>
>
>What do you tell people about manganese?
>
>
>
>RR
>
>
>
>
>
>
>
>>Lilli,
>
>>
>
>>don't tell me Ron uses manganese (hehehehe).
>
>>
>
>>
>
>>Gis la revido,
>
>>
>
>>Edouard Bastarache
>
>>Spertesperantisto
>
>
>
>Ron Roy
>
>RR#4
>
>15084 Little Lake Road
>
>Brighton, Ontario
>
>Canada
>
>K0K 1H0
>
>
>
>________________________________________________________________________
>______
>
>Clayart members may send postings to: clayart@lsv.ceramics.org
>
>
>
>You may look at the archives for the list, post messages, or change your
>
>subscription settings 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, or change your
>subscription settings here: http://www.acers.org/cic/clayart/
>
>Moderator of the list is Mel Jacobson who may be reached at melpots2@visi.com
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Ron Roy on thu 22 nov 07
Hi Ed,
New study from Banladesh says ingested is more of a prolem that we thought.
Symptoms like too much lead.
The BC study does not measure accumulated toxins and uses goverment
exposure levels - not good enough. They did not measure manganese either.
I have always said ventilation was important - some still don't understand
that yet.
I don't think minimising the problems is a good idea. Let everyone
understand what the problems are and decide for themselves. More potters
will live longer if we are careful and understand the risks.
Anyone who wants to understand the toxicity of Manganese should google
Manganese Toxicity - more than enough info there to convince anyone to be
careful with it.
RR
>Don't worry about that.
>
>Only 5 % of ingested manganese is absorbed by the gut,
>so forget about this route of entry.
>Manganese is not regulated for utilitarian wares.
>
>You have to worry about inhaled dusts and fumes,
>if you use some sort of ventilation the problem
>is not so important, fumes are 5 times more noxious
>than dusts; 1 mg/m3 for the fumes and 5 mg/m3 for
>dusts.
>
>Ventilation is a very important factor.
>
>Read the following text from experts :
>
>"AUTHOR: Bob Hirtle; Kay Teschke; Chris van Netten; Michael Brauer
>
>TITLE: Kiln Emissions and Potters' Exposures
>
>SOURCE: American Industrial Hygiene Association Journal v59 no10 p706-14 O '98
>
>The magazine publisher is the copyright holder of this article and it is
>reproduced with
>
>permission. Further reproduction of this article in violation of the
>copyright is prohibited.
>
>ABSTRACT
>
>Some ten thousand British Columbia potters work in small private studios,
>cooperative
>
>facilities, educational institutions, or recreation centers. There has
>been considerable
>
>concern that this diffuse, largely unregulated activity may involve
>exposures to
>
>unacceptable levels of kiln emissions. Pottery kiln emissions were
>measured at 50
>
>sites-10 from each of 5 categories: professional studios, recreation centers,
>
>elementary schools, secondary schools, and colleges. Area monitoring was
>done 76 cm
>
>from firing kilns and 1.6 m above the floor to assess breathing zone
>concentrations of
>
>nitrogen dioxide, carbon monoxide, sulfur dioxide, fluorides, aldehydes,
>aluminum,
>
>antimony, arsenic, barium, beryllium, boron, cadmium, chromium, cobalt,
>copper, gold,
>
>iron, lead, lithium, magnesium, manganese, mercury, nickel, selenium,
>silver, vanadium,
>
>and zinc. Personal exposures to the same metals were measured at 24 sites.
>Almost
>
>all measured values were well below permissible concentrations for British
>Columbia
>
>work sites and American Conference of Governmental Industrial Hygienists
>(ACGIH)
>
>threshold limit values (TLVs) with the following two exceptions. A single
>firing duration
>
>(495 minute) acrolein measurement adjacent to an electric kiln (0.109 ppm)
>exceeded
>
>these guidelines. One 15-minute sulfur dioxide measurement collected
>adjacent to a
>
>gas kiln (5.7 ppm) exceeded the ACGIH short-term exposure limit. The fact that
>
>concentrations in small, ventilated kiln rooms ranked among the highest
>measured
>
>gives rise to concern that unacceptable levels of contamination may exist
>where small
>
>kiln rooms remain unventilated. Custom designed exhaust hoods and
>industrial heating,
>
>ventilating, and air-conditioning systems were the most effective
>ventilation strategies.
>
>Passive diffusion and wall/window fans were least effective."
>
>
>
>Who made the diagnosis on Shaner, we do not know....
>
>
>
>
>
>Gis la revido,
>
>Edouard Bastarache
>Spertesperantisto
>
>Sorel-Tracy
>Quebec
>http://www.sorel-tracy.qc.ca/~edouardb/Welcome.html
>http://perso.orange.fr/smart2000/livres.htm
>http://www.pshcanada.com/Toxicology.htm
>http://www.ceramique.com/librairie/
>http://www.flickr.com/photos/30058682@N00/
>http://myblogsmesblogs.blogspot.com/
>
>
>
>
>
>
>
>
>
>----- Original Message -----
>From: "Ron Roy"
>To:
>Sent: Tuesday, November 20, 2007 2:06 AM
>Subject: Re: Barnard Clay substitute
>
>
>> Hi Ed,
>>
>> If the one you are talking about is on the digital fire site - I think it
>> needs updating.
>>
>> RR
>>
>>>Ron,
>>>
>>> "What do you tell people about manganese?
>>> RR"
>>>
>>>I tell them to read my article posted on the Net.
>>
>>>Edouard Bastarache
>>
>> Ron Roy
>> RR#4
>> 15084 Little Lake Road
>> Brighton, Ontario
>> Canada
>> K0K 1H0
>>
>>
>>__________________________________________________________________________
>>____
>> Clayart members may send postings to: clayart@lsv.ceramics.org
>>
>> You may look at the archives for the list, post messages, or change your
>> subscription settings here: http://www.acers.org/cic/clayart/
>>
>> Moderator of the list is Mel Jacobson who may be reached at melpots2@visi.com
>>
>>
>>
>> --
>> No virus found in this incoming message.
>> Checked by AVG Free Edition.
>> Version: 7.5.503 / Virus Database: 269.16.0/1139 - Release Date:
>>2007-11-19 12:35
>>
>>
>
>______________________________________________________________________________
>Clayart members may send postings to: clayart@lsv.ceramics.org
>
>You may look at the archives for the list, post messages, or change your
>subscription settings here: http://www.acers.org/cic/clayart/
>
>Moderator of the list is Mel Jacobson who may be reached at melpots2@visi.com
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Edouard Bastarache Inc. on fri 23 nov 07
Don,
The inorganic compounds do not penetrate the body
via skin like
some organic compounds, such as certain
tricarbonyls.
Gis la revido,
Edouard Bastarache
Spertesperantisto
Sorel-Tracy
Quebec
http://www.sorel-tracy.qc.ca/~edouardb/Welcome.html
http://perso.orange.fr/smart2000/livres.htm
http://www.pshcanada.com/Toxicology.htm
http://www.ceramique.com/librairie/
http://www.flickr.com/photos/30058682@N00/
http://myblogsmesblogs.blogspot.com/
----- Original Message -----
From: "Donald Burroughs"
To:
Sent: Friday, November 23, 2007 10:39 PM
Subject: Re: Barnard Clay substitute
> Hello Ron
>
> Spot on! Manganese toxicity is the stuff of
> legend so to speak as in the example of Hans
> Coper who
> while he created great pots with manganese
> rubbed into the surface did not have the
> advantage of
> nitrile gloves to protect him from ingestion
> through the pores of his hands. Consequently,
> manganese toxicity = Parkinson's disease. How
> many more great pots might Coper have produced
> were it not for some sort of protective barrier?
> To not heed the now easliy available research
> (MSDS)
> which came about through legislation and labour
> movement concerns about a safe work environment
> is simply sheer folly. SAFE = S = Spot the
> hazard
>
> A = Assess the risk
>
> F = Find a safer way
>
> E = Everyday
> source: http://safemanitoba.com
>
> Don Burroughs
>
> ______________________________________________________________________________
> Clayart members may send postings to:
> clayart@lsv.ceramics.org
>
> You may look at the archives for the list, post
> messages, or change your
> subscription settings here:
> http://www.acers.org/cic/clayart/
>
> Moderator of the list is Mel Jacobson who may be
> reached at melpots2@visi.com
>
>
>
> --
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.5.503 / Virus Database:
> 269.16.4/1147 - Release Date: 2007-11-23 09:19
>
>
Ivor and Olive Lewis on fri 23 nov 07
Dear Ron,
Not sure if my message about Saturated Manganese glazes was published =
but I picked up on your note as follows
<he had know the dangers of using a saturated manganese glaze.>>
Recently, due to mismanagement, finished up with a bucket of glaze =
overloaded with Manganese dioxide. I used it to glaze some small bowls =
and a teapot. My results were most attractive, especially in the way =
enhanced surface tension had moved the molten glaze over deep textured =
surfaces leaving the high relief with no more than a surface shine =
through which white clay glowed.
Last week I tested this modification with the raw citric acid, fresh =
Lime juice to be precise, I put the acid inside of the footring where =
the glaze had mat and bright surfaces. After three days there was no =
visible change to either. The bright parts were still highly reflective =
and the shape of the boundary with mat parts was unchanged . There was =
no visible bleaching of the colour.
I would suggest that there are reactions between Manganese dioxide and =
Silicon dioxide with the potential of one or other of Manganese =
Orthosilicate or Manganese metasilicate being formed if the glaze =
devitrifies. Both are insoluble in water.
I agree that there are problems with Manganese compounds but perhaps we =
need to discriminate between technical exposure during manufacture and =
the potential for ingestion through using pots that rely on Manganese =
dioxide or carbonate to create colour. You give David Shaner as an =
example. Perhaps Hans Coper was another victim. His clay body contained =
1.5% MnO2. His basic stain was based on manganese and iron, The recipe =
was 3 parts Manganese dioxide and 2 parts Yellow Ochre in a medium of =
water and Gum Arabic. His greenware was scoured and burnished=20
Hans Copper died 16 June 1981 from Motor Neurone Disease the cause of =
which was, at that time, unknown.=20
When in doubt, don't. At all times exercise caution.
All the best,
Ivor
Donald Burroughs on fri 23 nov 07
Hello Ron
Spot on! Manganese toxicity is the stuff of legend so to speak as in the example of Hans Coper who
while he created great pots with manganese rubbed into the surface did not have the advantage of
nitrile gloves to protect him from ingestion through the pores of his hands. Consequently,
manganese toxicity = Parkinson's disease. How many more great pots might Coper have produced
were it not for some sort of protective barrier? To not heed the now easliy available research (MSDS)
which came about through legislation and labour movement concerns about a safe work environment
is simply sheer folly. SAFE = S = Spot the hazard
A = Assess the risk
F = Find a safer way
E = Everyday
source: http://safemanitoba.com
Don Burroughs
Ron Roy on sun 25 nov 07
Hi Ivor,
What we need to do is limit inhalation of fumes and dust - that is the real
problem for the potter.
You need to realize that the acid test that shows etching is only to show
grossly unstable glazes. What you have observed is not comparable to a lab
test of that glaze.
What is important in this is the basic level of manganese in your system -
from food, water and exposure to dust and fumes. If you were at toxic
levels already it would be foolish to add to the load in any way.
The study in Bangladesh was done on children who drank water with dissolved
manganese in it. Manganese contaminated water tastes bad but if it's the
only water you drink it. The point is - every ones "load of manganese is
going up - as David says - it's in the gas now - levels are rising
everywhere.
I have one of David Shaners pillow pots - glazed with his saturated
manganese glaze - a beautiful pot, So I understand just how attractive
yours are - but I would never use such a pot to eat out of - or store food
in or cook in. I have tempted the Gods in many ways before I knew better -
I am now concentrating on doing things right.
RR
>Dear Ron,
>Not sure if my message about Saturated Manganese glazes was published but
>I picked up on your note as follows
><>he had know the dangers of using a saturated manganese glaze.>>
>Recently, due to mismanagement, finished up with a bucket of glaze
>overloaded with Manganese dioxide. I used it to glaze some small bowls and
>a teapot. My results were most attractive, especially in the way enhanced
>surface tension had moved the molten glaze over deep textured surfaces
>leaving the high relief with no more than a surface shine through which
>white clay glowed.
>Last week I tested this modification with the raw citric acid, fresh Lime
>juice to be precise, I put the acid inside of the footring where the glaze
>had mat and bright surfaces. After three days there was no visible change
>to either. The bright parts were still highly reflective and the shape of
>the boundary with mat parts was unchanged . There was no visible bleaching
>of the colour.
>I would suggest that there are reactions between Manganese dioxide and
>Silicon dioxide with the potential of one or other of Manganese
>Orthosilicate or Manganese metasilicate being formed if the glaze
>devitrifies. Both are insoluble in water.
>I agree that there are problems with Manganese compounds but perhaps we
>need to discriminate between technical exposure during manufacture and the
>potential for ingestion through using pots that rely on Manganese dioxide
>or carbonate to create colour. You give David Shaner as an example.
>Perhaps Hans Coper was another victim. His clay body contained 1.5% MnO2.
>His basic stain was based on manganese and iron, The recipe was 3 parts
>Manganese dioxide and 2 parts Yellow Ochre in a medium of water and Gum
>Arabic. His greenware was scoured and burnished
>Hans Copper died 16 June 1981 from Motor Neurone Disease the cause of
>which was, at that time, unknown.
>When in doubt, don't. At all times exercise caution.
>All the best,
>Ivor
>
>______________________________________________________________________________
>Clayart members may send postings to: clayart@lsv.ceramics.org
>
>You may look at the archives for the list, post messages, or change your
>subscription settings here: http://www.acers.org/cic/clayart/
>
>Moderator of the list is Mel Jacobson who may be reached at melpots2@visi.com
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Donald Burroughs on mon 26 nov 07
Hello Edouard
Had trouble responding as the list was not accepting messages for me.
While it might be true that manganese cannot penetrate the skin in it's
unblemished form, what would one say if it perforated, for example a paper
cut or a ceramic cut which can take some time to heal. Everyone's clotting
ability is different so a cut which has drawn blood,does in fact, leave
one exposed to contamination. Given that this is not a perfect world, I
will still opt to use nitrile gloves as a barrier when glazing or using
slips, engobes,etc.. As for clay I could not bear to have it's feel
negated by the nitrile glove. I use the rule of thumb coined by
safemanitoba.com
Safe =
S = Spot the Hazard
A = Assess the Risk
F = Find a Safer Way
E = Everyday
Regards Don Burroughs
Edouard Bastarache Inc. on mon 26 nov 07
Donald,
as my sister-in-law, a former English teacher,
used to say :
"Whatever turns you on"
I do not think a small skin cut will absorb
sufficiently to cause
acute or chronic intoxications.
It will certainly not absorb a ten-ton truckload.
(Heheheheh).
Naturally when the skin barier is broken things
may happen such
as infections even if the microbes are
saprophytes.
As for myself, not being a full time potter, I
stay away from clay
when my skin barrier is broken and do other works
related to
ceramics till the wound has healed. I do not need
to use gloves,
because it would probably feel like making love
with standard-
issued Army's french safes (capotes anglaises on
the other of
the Channel).
Gis la revido,
Edouard Bastarache
Spertesperantisto
Sorel-Tracy
Quebec
http://www.sorel-tracy.qc.ca/~edouardb/Welcome.html
http://perso.orange.fr/smart2000/livres.htm
http://www.pshcanada.com/Toxicology.htm
http://www.ceramique.com/librairie/
http://www.flickr.com/photos/30058682@N00/
http://myblogsmesblogs.blogspot.com/
----- Original Message -----
From: "Donald Burroughs"
To:
Sent: Monday, November 26, 2007 11:09 AM
Subject: Re: Barnard Clay substitute
> Hello Edouard
>
> Had trouble responding as the list was not
> accepting messages for me.
> While it might be true that manganese cannot
> penetrate the skin in it's
> unblemished form, what would one say if it
> perforated, for example a paper
> cut or a ceramic cut which can take some time to
> heal. Everyone's clotting
> ability is different so a cut which has drawn
> blood,does in fact, leave
> one exposed to contamination. Given that this is
> not a perfect world, I
> will still opt to use nitrile gloves as a
> barrier when glazing or using
> slips, engobes,etc.. As for clay I could not
> bear to have it's feel
> negated by the nitrile glove. I use the rule of
> thumb coined by
> safemanitoba.com
> Safe =
> S = Spot the Hazard
> A = Assess the Risk
> F = Find a Safer Way
> E = Everyday
>
> Regards Don Burroughs
>
> ______________________________________________________________________________
> Clayart members may send postings to:
> clayart@lsv.ceramics.org
>
> You may look at the archives for the list, post
> messages, or change your
> subscription settings here:
> http://www.acers.org/cic/clayart/
>
> Moderator of the list is Mel Jacobson who may be
> reached at melpots2@visi.com
>
>
>
> --
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.5.503 / Virus Database:
> 269.16.7/1152 - Release Date: 2007-11-26 10:50
>
>
Ivor and Olive Lewis on tue 27 nov 07
Dear Ron,
One thing I have always done is to use clear colourless glazes for the =
interiors of domestic pots. Only wish I had a Spectrometer for fast =
determinations of leachate extractions. Viewing the flame that issues =
from the stack through a spectroscope during reduction is interesting. =
It was a while before I was able to account for the green lines since my =
instrument is not calibrated, Then I realised that it was possibly =
Boron. Not sure what the toxicologists have to say about Boron.
The story I heard was that it was arsenic that is in the goundwater in =
Bangladesh, but knowing that the delta region takes discharges from such =
a vast land area you would not wish to imbibe anything from a local =
well.
Never was on to hand around a kiln during a firing and when I have to I =
wear a respirator. Back in 1990 I spent time at a summer school with =
Jane Hamlyn working on Salt Glazing. I was the only person who wore a =
face mask during firings. Acid and particulate filters are essential =
even if they are uncomfortable.
Good to hear from you.
Best regards,
Ivor
Ron Roy on thu 29 nov 07
Hi Ivor,
Boron is not without it's effects - sprinkle it around your house to repel
insects for instance but keep the pets from eating it - lethal doses have
been absorbed from old time burn treatments.
Perhaps a look on the internet is in order - best to keep the lids on the
glaze buckets at any rate.
RR
>Dear Ron,
>
>One thing I have always done is to use clear colourless glazes for the
>interiors of domestic pots. Only wish I had a Spectrometer for fast
>determinations of leachate extractions. Viewing the flame that issues from
>the stack through a spectroscope during reduction is interesting. It was a
>while before I was able to account for the green lines since my instrument
>is not calibrated, Then I realised that it was possibly Boron. Not sure
>what the toxicologists have to say about Boron.
>
>The story I heard was that it was arsenic that is in the goundwater in
>Bangladesh, but knowing that the delta region takes discharges from such a
>vast land area you would not wish to imbibe anything from a local well.
>
>Never was on to hand around a kiln during a firing and when I have to I
>wear a respirator. Back in 1990 I spent time at a summer school with Jane
>Hamlyn working on Salt Glazing. I was the only person who wore a face mask
>during firings. Acid and particulate filters are essential even if they
>are uncomfortable.
>
>Good to hear from you.
>
>Best regards,
>
>Ivor
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Jon Pacini on thu 29 nov 07
Greetings All ---Hi Ron
---you wrote "Boron is not without it's effects - sprinkle it around your
house to repel insects for instance"
Boron doesn't repel insects, I believe powdered borax gets into the joints
of their exo-skeletons and dries them out, rendering them immobile.
A very traditional use of Boraxo soap in the Hawaiian Islands by the way.
For the 9 years I had my studio in Kona, Hawai'i I used powdered Borax to
keep the crawling insects at bay.
It won't "repel" flying insects, unless you manage to throw and hit them
with it.
Best regards
Jon Pacini
Clay Manager
Laguna Clay Co
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