Birgit Wright on sun 17 apr 11
Hi Ron=3D3B I will call the supplier on monday about the encapsulated cadm=
iu=3D
m. But I have a litre or so of the Chrome-Tin Raspberry=3D2C While it bre=
ak=3D
s ok on vertical sides it still obscures texture on horizontal surfaces. Bu=
=3D
t I will try it with the wiped off technique I have been using with the sli=
=3D
p. =3D20
=3D20
Just an aside=3D2C when you mistakenly mix up the raspberry with only .75% =
of=3D
tin instead of 7.5% tin you get a really beautiful light minty green with =
=3D
infinitesimal red flecks that makes it really warm. Guess how I know...
=3D20
The post with the mason red stain tile is http://birgitspots.blogspot.com/.
=3D20
When I have done the raspberry test I will post a photo.
=3D20
Till then=3D2C Adieu=3D2C Birgit
=3D20
=3D20
=3D20
=3D20
> Date: Sat=3D2C 16 Apr 2011 17:15:46 -0400
> From: ronroy@CA.INTER.NET
> Subject: Re: Red stained slip under MC6 clear glaze?
> To: Clayart@LSV.CERAMICS.ORG
>=3D20
> Hi Birgit=3D2C
>=3D20
> Lead is not the way to red - cadmium gives the red colour and it is
> the problem - there must be stains that are made with encapsulated
> cadmium but you will still need to have some testing done.
>=3D20
> Fist step is call your supplier and see which red stains are made with
> encapsulated cadmium.
>=3D20
> There are other ways to get pinks and reds by the way - does anyone
> use chrome tin combinations in the way Birgit decorates.
>=3D20
> Birgit - post the url to those pictures again.
>=3D20
> Canadian Department of Health=3D2C hazardous Products (Ceramics and
> Glassware) regulations if you want to find the regulations for lead
> and cadmium.
>=3D20
> http://laws.justice.gc.ca/en/H-3/SOR-98-176/130617.html
>=3D20
> Perhaps you can find a way to use our raspberry glaze - working some
> into the texture and a clear version over?
>=3D20
> RR
>=3D20
>=3D20
> Quoting Birgit Wright :
>=3D20
> >
> > Hi Ron=3D3B I Don't know that I need to use the cadmium red if lead is
> > better or safer under the glaze. Is there a lead based stain out
> > there=3D2C a mason stain or the newer Chinese ones at PSH. I have had a
> > lot of requests for red so I am looking into it=3D2C I know I need to
> > learn a lot and I am ready to do that=3D2C as best I can. Could I
> > please just ask how to frame the question of where to look for
> > regulations=3D2C Which government agency do I ask?
> > Thanks again=3D2C Birgit
=3D
MJ on thu 21 apr 11
Hi - This discussion raised a couple of questions for me regarding stains =
-
especially red stains. If my memory is correct, you first mentioned using =
a
red mason stain to make red slip. Is there a difference between a red maso=
n
stain and an encapsulated stain? Same question regarding any differences
between inclusion and encapsulated.
If you have a glaze that is fired to cone 6 and has as an ingredient an
inclusion stain, is it food safe? Same question regarding encapsulated
stains if there is a difference. If this was embedded in the glaze, how
sure can you be that it is safe? If you have it tested and it proves safe
on 1 item, can you be certain that later fired pieces are equally safe? I
do use cones so I can certainly see that this would give some comfort.
Chrome reds are nice, but it seems that the mason stains in a glaze can mak=
e
more varieties of red.
Regarding toxicity and leaching of cadmium - is it only food surfaces where
you need to concern yourself? Any way to self test for starters - and then
pass along to a lab if it passes. How about outside of pieces that never
touch food or sculptural pieces?
Birgit, I am curious as to what conclusions you formed regarding your
treatment.
As always, thanks in advance for any insights.
Cheers, MJ
On Sun, Apr 17, 2011 at 7:18 AM, Birgit Wright wro=
te:
> Hi Ron; I will call the supplier on monday about the encapsulated cadmiu=
m.
> But I have a litre or so of the Chrome-Tin Raspberry, While it breaks o=
k
> on vertical sides it still obscures texture on horizontal surfaces. But I
> will try it with the wiped off technique I have been using with the slip.
>
> Just an aside, when you mistakenly mix up the raspberry with only .75% of
> tin instead of 7.5% tin you get a really beautiful light minty green with
> infinitesimal red flecks that makes it really warm. Guess how I know...
>
> The post with the mason red stain tile is http://birgitspots.blogspot.com=
/
> .
>
> When I have done the raspberry test I will post a photo.
>
> Till then, Adieu, Birgit
>
>
>
>
> > Date: Sat, 16 Apr 2011 17:15:46 -0400
> > From: ronroy@CA.INTER.NET
> > Subject: Re: Red stained slip under MC6 clear glaze?
> > To: Clayart@LSV.CERAMICS.ORG
> >
> > Hi Birgit,
> >
> > Lead is not the way to red - cadmium gives the red colour and it is
> > the problem - there must be stains that are made with encapsulated
> > cadmium but you will still need to have some testing done.
> >
> > Fist step is call your supplier and see which red stains are made with
> > encapsulated cadmium.
> >
> > There are other ways to get pinks and reds by the way - does anyone
> > use chrome tin combinations in the way Birgit decorates.
> >
> > Birgit - post the url to those pictures again.
> >
> > Canadian Department of Health, hazardous Products (Ceramics and
> > Glassware) regulations if you want to find the regulations for lead
> > and cadmium.
> >
> > http://laws.justice.gc.ca/en/H-3/SOR-98-176/130617.html
> >
> > Perhaps you can find a way to use our raspberry glaze - working some
> > into the texture and a clear version over?
> >
> > RR
> >
> >
> > Quoting Birgit Wright :
> >
> > >
> > > Hi Ron; I Don't know that I need to use the cadmium red if lead is
> > > better or safer under the glaze. Is there a lead based stain out
> > > there, a mason stain or the newer Chinese ones at PSH. I have had a
> > > lot of requests for red so I am looking into it, I know I need to
> > > learn a lot and I am ready to do that, as best I can. Could I
> > > please just ask how to frame the question of where to look for
> > > regulations, Which government agency do I ask?
> > > Thanks again, Birgit
>
Ron Roy on fri 22 apr 11
Hi MJ,
I think encapsulated and inclusion are the same - much safer than
cadmium oxide. Still - not all the crystals are complete - in other
words broken - and you can smell cadmium when you open a container of
encapsulated cadmium - be careful!
You are still responsible for all the cadmium glazes you use. I don't
know how you would find out if they release more than allowed into
food except by testing. I don't know if there is a home test kit and
if there is how trustworthy it would be.
I think you are asking if encapsulated cadmium can be released by
acidic food - no I don't but not all of it is encapsulated so the
glaze needs to be durable.
If one batch of glaze tests OK - I would think the rest should be OK
but I also think you could get different results for a few reasons.
Each batch of glaze would have to be tested I think.
The law in Canada says the glaze inside the pot must pass the test and
down a certain amount on the outside so wet lips don't touch any lead
or cadmium releasing glaze. The rules also include any pot that can
hold a liquid - or they have to have a hole in them or print in the
clay warning of toxicity.
Not sure I want to answer more about this - it does not sound viable
or economical to me.
RR
Quoting MJ :
> Hi - This discussion raised a couple of questions for me regarding stain=
s -
> especially red stains. If my memory is correct, you first mentioned usin=
g a
> red mason stain to make red slip. Is there a difference between a red ma=
son
> stain and an encapsulated stain? Same question regarding any differences
> between inclusion and encapsulated.
>
> If you have a glaze that is fired to cone 6 and has as an ingredient an
> inclusion stain, is it food safe? Same question regarding encapsulated
> stains if there is a difference. If this was embedded in the glaze, how
> sure can you be that it is safe? If you have it tested and it proves saf=
e
> on 1 item, can you be certain that later fired pieces are equally safe? =
I
> do use cones so I can certainly see that this would give some comfort.
>
> Chrome reds are nice, but it seems that the mason stains in a glaze can m=
ake
> more varieties of red.
>
> Regarding toxicity and leaching of cadmium - is it only food surfaces whe=
re
> you need to concern yourself? Any way to self test for starters - and th=
en
> pass along to a lab if it passes. How about outside of pieces that never
> touch food or sculptural pieces?
Birgit Wright on fri 22 apr 11
Hi MJ=3D3B I looked up the mason stain I am using and it is an encapsulate=
d =3D
cadmium red. When I talked to the suppliers at Pottery supply house they g=
=3D
ave me the site for BSC Labs=3D2C
http://www.bsclab.com/ =3D2C Brandywine Science Center=3D2C they do potte=
ry g=3D
laze testing in Pennsylvania=3D2C reasonabley priced I think=3D2C look the=
m up=3D
.
=3D20
These are the cups I am having tested. the red slip is 20gr. stain and 100=
=3D
gr. stoneware clay.
http://birgitspots.blogspot.com/2011/04/red-test-cups.html
=3D20
I will let everyone know what the result is when I get it back=3D2C Could b=
e =3D
a couple of weeks for all I know.
=3D20
I haven't got a photo yet but I did try wiping on the MC6 raspberry glaze a=
=3D
nd covering with clear=3D2C it was just really washed out=3D2C not unlovely=
but=3D
not what I am looking for. I will post a photo later. just kinda busy righ=
=3D
t now.
Ciao=3D2C Birgit
=3D20
=3D20
> Date: Thu=3D2C 21 Apr 2011 19:20:55 -0700
> From: mjcarizona@GMAIL.COM
> Subject: Re: A raspberry try=3D2C was RE: Red stained slip
> To: Clayart@LSV.CERAMICS.ORG
>=3D20
> Hi - This discussion raised a couple of questions for me regarding stains=
=3D
-
> especially red stains. If my memory is correct=3D2C you first mentioned u=
si=3D
ng a
> red mason stain to make red slip. Is there a difference between a red mas=
=3D
on
> stain and an encapsulated stain? Same question regarding any differences
> between inclusion and encapsulated.
>=3D20
> If you have a glaze that is fired to cone 6 and has as an ingredient an
> inclusion stain=3D2C is it food safe? Same question regarding encapsulate=
d
> stains if there is a difference. If this was embedded in the glaze=3D2C h=
ow
> sure can you be that it is safe? If you have it tested and it proves safe
> on 1 item=3D2C can you be certain that later fired pieces are equally saf=
e?=3D
I
> do use cones so I can certainly see that this would give some comfort.
>=3D20
> Chrome reds are nice=3D2C but it seems that the mason stains in a glaze c=
an=3D
make
> more varieties of red.
>=3D20
> Regarding toxicity and leaching of cadmium - is it only food surfaces whe=
=3D
re
> you need to concern yourself? Any way to self test for starters - and the=
=3D
n
> pass along to a lab if it passes. How about outside of pieces that never
> touch food or sculptural pieces?
>=3D20
> Birgit=3D2C I am curious as to what conclusions you formed regarding your
> treatment.
>=3D20
> As always=3D2C thanks in advance for any insights.
> Cheers=3D2C MJ
>=3D20
>=3D20
>=3D20
> On Sun=3D2C Apr 17=3D2C 2011 at 7:18 AM=3D2C Birgit Wright otmail=3D
.com>wrote:
>=3D20
> > Hi Ron=3D3B I will call the supplier on monday about the encapsulated c=
ad=3D
mium.
> > But I have a litre or so of the Chrome-Tin Raspberry=3D2C While it brea=
ks=3D
ok
> > on vertical sides it still obscures texture on horizontal surfaces. But=
=3D
I
> > will try it with the wiped off technique I have been using with the sli=
=3D
p.
> >
> > Just an aside=3D2C when you mistakenly mix up the raspberry with only .=
75=3D
% of
> > tin instead of 7.5% tin you get a really beautiful light minty green wi=
=3D
th
> > infinitesimal red flecks that makes it really warm. Guess how I know...
> >
> > The post with the mason red stain tile is http://birgitspots.blogspot.c=
=3D
om/
> > .
> >
> > When I have done the raspberry test I will post a photo.
> >
> > Till then=3D2C Adieu=3D2C Birgit
> >
> >
> >
> >
> > > Date: Sat=3D2C 16 Apr 2011 17:15:46 -0400
> > > From: ronroy@CA.INTER.NET
> > > Subject: Re: Red stained slip under MC6 clear glaze?
> > > To: Clayart@LSV.CERAMICS.ORG
> > >
> > > Hi Birgit=3D2C
> > >
> > > Lead is not the way to red - cadmium gives the red colour and it is
> > > the problem - there must be stains that are made with encapsulated
> > > cadmium but you will still need to have some testing done.
> > >
> > > Fist step is call your supplier and see which red stains are made wit=
=3D
h
> > > encapsulated cadmium.
> > >
> > > There are other ways to get pinks and reds by the way - does anyone
> > > use chrome tin combinations in the way Birgit decorates.
> > >
> > > Birgit - post the url to those pictures again.
> > >
> > > Canadian Department of Health=3D2C hazardous Products (Ceramics and
> > > Glassware) regulations if you want to find the regulations for lead
> > > and cadmium.
> > >
> > > http://laws.justice.gc.ca/en/H-3/SOR-98-176/130617.html
> > >
> > > Perhaps you can find a way to use our raspberry glaze - working some
> > > into the texture and a clear version over?
> > >
> > > RR
> > >
> > >
> > > Quoting Birgit Wright :
> > >
> > > >
> > > > Hi Ron=3D3B I Don't know that I need to use the cadmium red if lead=
i=3D
s
> > > > better or safer under the glaze. Is there a lead based stain out
> > > > there=3D2C a mason stain or the newer Chinese ones at PSH. I have h=
ad=3D
a
> > > > lot of requests for red so I am looking into it=3D2C I know I need =
to
> > > > learn a lot and I am ready to do that=3D2C as best I can. Could I
> > > > please just ask how to frame the question of where to look for
> > > > regulations=3D2C Which government agency do I ask?
> > > > Thanks again=3D2C Birgit
> >
=3D
| |
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