search  current discussion  categories  kilns & firing - raku 

red glaze for raku

updated tue 1 oct 02

 

Karin Hurt on thu 26 sep 02


Recently I asked Clayart members for help with a red Raku glaze.

I received a suggestion for "Essence Red" from one of our members.

My birthday was close and my daughter sent me "Essence Red" as well as
another glaze.

Yesterday I fired my first "Essence Red" bowl, it drew uuuh's and ahhh's.

Today I ordered more from: www.clayartcenter.com, and got a ton of free
advice as well. I wanted to pass on the address of this great organization.

Karin
www.laughingbearpottery.com

Robert Izzi on fri 27 sep 02


I think I have seen Essence Red raku and it is quite stunning but doesn't
have a lead base?I have shied away from using it because of the lead. nice
glaze however.

Bob ,gcovepottery

L. P. Skeen on fri 27 sep 02


The description says CADMIUM, but not lead. Is cadmium a form of lead? I
have no idea.

L
----- Original Message -----
From: "Robert Izzi"
To:
Sent: Friday, September 27, 2002 12:03 AM
Subject: Re: Red Glaze for Raku


> I think I have seen Essence Red raku and it is quite stunning but doesn't
> have a lead base?I have shied away from using it because of the lead. nice
> glaze however.
>
> Bob ,gcovepottery
>
>
____________________________________________________________________________
__
> 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.
>

GORMO1@AOL.COM on sat 28 sep 02


cadmium ox -CdO they now have made it to be insoluble in glazes
and slips and they say nontoxic. Conforms to ASTM-D4236 This info
came from a label on a red underglaze from Campbell's ceramics and the
potters dictionary by the hammer's. They just frtted the Cdo or wrapped it
so the CdO Could not become soluble.


Jim Gorman
500 Southgte Dr.
Blacksburg,Va. 24060
540-953-0673

Craig Clark on sat 28 sep 02


L, Cadmium is an element. Lead is an element. They are different. Good rule
of thumb for those of us that are chemically challenged. Lead Badddddddd.
Lead Baddddddd. Lead Very Very Baddddddd. Though I'm sure there are some who
will disagree. I recently heard someone who works in a ceramics supply store
say that the data on lead is somehow misconstrued of false. I think the
individual is a nut case.
Craig
----- Original Message -----
From: "L. P. Skeen"
To:
Sent: Friday, September 27, 2002 3:52 PM
Subject: Re: Red Glaze for Raku


> The description says CADMIUM, but not lead. Is cadmium a form of lead? I
> have no idea.
>
> L
> ----- Original Message -----
> From: "Robert Izzi"
> To:
> Sent: Friday, September 27, 2002 12:03 AM
> Subject: Re: Red Glaze for Raku
>
>
> > I think I have seen Essence Red raku and it is quite stunning but
doesn't
> > have a lead base?I have shied away from using it because of the lead.
nice
> > glaze however.
> >
> > Bob ,gcovepottery
> >
> >
>
____________________________________________________________________________
> __
> > 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.
> >
>
>
____________________________________________________________________________
__
> 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.

Brooks Ratledge on sun 29 sep 02


Cadmium is also very dangerous. A friend became very ill after using
commercial bottles of cadmium red glaze - not the encapsulated red. She was
seriously ill for several months and it took years for her to recover enough
to get back to her life - sans red glaze. Patricia Harden
-----------------------------------------------------
Click here for Free Video!!
http://www.gohip.com/free_video/

-----Original Message-----
From: Craig Clark
To: CLAYART@LSV.CERAMICS.ORG
Date: Saturday, September 28, 2002 11:48 PM
Subject: Re: Red Glaze for Raku


>L, Cadmium is an element. Lead is an element. They are different. Good rule
>of thumb for those of us that are chemically challenged. Lead Badddddddd.
>Lead Baddddddd. Lead Very Very Baddddddd. Though I'm sure there are some
who
>will disagree. I recently heard someone who works in a ceramics supply
store
>say that the data on lead is somehow misconstrued of false. I think the
>individual is a nut case.
>Craig
>----- Original Message -----
>From: "L. P. Skeen"
>To:
>Sent: Friday, September 27, 2002 3:52 PM
>Subject: Re: Red Glaze for Raku
>
>
>> The description says CADMIUM, but not lead. Is cadmium a form of lead?
I
>> have no idea.
>>
>> L
>> ----- Original Message -----
>> From: "Robert Izzi"
>> To:
>> Sent: Friday, September 27, 2002 12:03 AM
>> Subject: Re: Red Glaze for Raku
>>
>>
>> > I think I have seen Essence Red raku and it is quite stunning but
>doesn't
>> > have a lead base?I have shied away from using it because of the lead.
>nice
>> > glaze however.
>> >
>> > Bob ,gcovepottery
>> >
>> >
>>
>___________________________________________________________________________
_
>> __
>> > 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.
>> >
>>
>>
>___________________________________________________________________________
_
>__
>> 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.
>
>___________________________________________________________________________
___
>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.

Gavin Stairs on sun 29 sep 02


Hi again,

Yes, lead is an element, symbol Pb, which is derived from the Latin
plumbum. Cadmium is also an element, symbol Cd, derived from the common
name.

Lead is a systemic, nerve affecting, heavy metal poison. So is
Cadmium. The pottery use of Lead is as a glass forming flux which treats
colors well and makes a nice velvety soft surface. Melts really
nice. Cadmium on the other hand is a strong coloring oxide which makes
reds and oranges all the way down to really rich yellows.

Potters would rather believe that both are really good for you, and keep on
using them. This isn't true, so they like to cry about it.

Particularly in Great Britain, it seems, potters have been told that
fritted Lead is pretty harmless, as the Lead is retained in the inert
silica framework and does not leach. The terms lead bisilicate and lead
trisilicate refer to these formulations, respectively two and three moles
of silica per mole of lead oxide. More recent research tends to refute
this claim, especially for lead silicate powders breathed into the lungs.

Many stains and frits contain either Lead or Cadmium or both. So called
encapsulated frits were developed to deal with the problem. These are
zircon-silicates containing colorants, sometimes including Cadmium. The
theory, and to varying degrees the practice, is that the extremely
refractory zircon-silica lattice will prevent the Cadmium etc., from
leaching out of the finished glaze.

Both are subject to regulations on amount leaching from food containers
sold to the public in the US and elsewhere.

For more info, wait ten seconds and Edouard will post the whole toxicology
of both elements in all their compounds. Or go to the DOE site that
specifies the regulations. I think California has even tighter restrictions.

There's lots about Lead and Cadmium in the archives. Have fun. Gavin

At 01:59 AM 28/09/2002 -0500, you wrote:
>L, Cadmium is an element. Lead is an element. They are different. Good rule
>of thumb for those of us that are chemically challenged. Lead Badddddddd.
>Lead Baddddddd. Lead Very Very Baddddddd. Though I'm sure there are some who
>will disagree. I recently heard someone who works in a ceramics supply store
>say that the data on lead is somehow misconstrued of false. I think the
>individual is a nut case.
>Craig
>----- Original Message -----
>From: "L. P. Skeen"
>To:
>Sent: Friday, September 27, 2002 3:52 PM
>Subject: Re: Red Glaze for Raku
>
>
> > The description says CADMIUM, but not lead. Is cadmium a form of lead? I
> > have no idea.

Alan D. Scott on sun 29 sep 02


Cadmium is also Badddddddddd. Very Baddddddddddd. Very Very
Badddddddddd. Don't eat it for from a pot glazed with Essence Red.

Al

P.S. In USA, the federal government does have standards for both Cadmium
and Lead in ceramic glazes.

-----Original Message-----
From: Ceramic Arts Discussion List [mailto:CLAYART@LSV.CERAMICS.ORG]On
Behalf Of Craig Clark
Sent: Friday, September 27, 2002 11:59 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: Red Glaze for Raku


L, Cadmium is an element. Lead is an element. They are different. Good
rule
of thumb for those of us that are chemically challenged. Lead Badddddddd.
Lead Baddddddd. Lead Very Very Baddddddd. Though I'm sure there are some
who
will disagree. I recently heard someone who works in a ceramics supply
store
say that the data on lead is somehow misconstrued of false. I think the
individual is a nut case.
Craig
----- Original Message -----
From: "L. P. Skeen"
To:
Sent: Friday, September 27, 2002 3:52 PM
Subject: Re: Red Glaze for Raku


> The description says CADMIUM, but not lead. Is cadmium a form of lead?
I
> have no idea.
>
> L
> ----- Original Message -----
> From: "Robert Izzi"
> To:
> Sent: Friday, September 27, 2002 12:03 AM
> Subject: Re: Red Glaze for Raku
>
>
> > I think I have seen Essence Red raku and it is quite stunning but
doesn't
> > have a lead base?I have shied away from using it because of the lead.
nice
> > glaze however.
> >
> > Bob ,gcovepottery
> >
> >
>
__________________________________________________________________________
__
> __
> > 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.
> >
>
>
__________________________________________________________________________
__
__
> 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.

__________________________________________________________________________
____
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.

Edouard Bastarache on sun 29 sep 02


" For more info, wait ten seconds and Edouard will post the whole toxicology
of both elements in all their compounds. Or go to the DOE site that
specifies the regulations. I think California has even tighter
restrictions.
Gavin"



Laffffffffffff Gavin,

for more info on lead and ceramics go to:

http://perso.wanadoo.fr/smart2000/Pb%20legislations.htm
http://perso.wanadoo.fr/smart2000/plomb_lead.htm

or:

http://digitalfire.com/education/toxicity/materialsafety.html


Later,


Edouard Bastarache
Irreductible Quebecois
Indomitable Quebeker
Sorel-Tracy
Quebec
edouardb@sorel-tracy.qc.ca
http://sorel-tracy.qc.ca/~edouardb/
http://perso.wanadoo.fr/smart2000/index.htm

"> For more info, wait ten seconds and Edouard will post the whole
toxicology
> of both elements in all their compounds. Or go to the DOE site that
> specifies the regulations. I think California has even tighter
restrictions.
Gavin"

L. P. Skeen on sun 29 sep 02


> I recently heard someone who works in a ceramics supply store
> say that the data on lead is somehow misconstrued of false. I think the
individual is a nut case.
> Craig


I'd have to agree with that; no WAY would I mess around with lead if I knew
it was there. OTOH, I was at Cermatech a few years ago when Cerdec guy was
there telling about his encapsulated cadmium stain that makes red. My
understanding from that was that the encapsulation makes the cadmium safe.
PRoblem is, we don't know which kind of cadmium the Essence Red folks are
using. Wonder if they'd tell.............?

L

Pottery by Dai on sun 29 sep 02


Patricia, could you give us some idea of how your friend "ingested"
cadmium? Fumes? Through the skin? Any ideas? There are quite a few
chemicals we use which are dangerous to us (i.e.chrome ox.) but if used with
all the precautions needed, shouldn't be worrisome. I'd like to try this
red raku glaze, and want to know if I should use latex gloves when applying,
or not stand near or downwind of the kiln, or all of the above.
Dai in Armstrong, BC

dai@potterybydai.com
potterybydai@telus.net
nightfire@telus.net
www.potterybydai.com

Take your work seriously---take yourself lightly. Unknown

Cate Loveland on sun 29 sep 02


Am I missing something in this discussion? Raku firings are by definition
not meant to hold liquid and are not food-safe. Cadmium is poisonous, but if
you use the glaze carefully, wipe up wet, use gloves and wash up well when
you are finished, and fire well-ventilated (my kiln is outside, under an
overhang), is it dangerous to use it? I was all set to go order some and try
it out.
TIA
Cate in AZ

Karen Shapiro on sun 29 sep 02


To all you who are worrying about using the Essence Red Raku glaze:

I know I tend not to be as careful as I should, but I use this glaze all the time and am still alive and kicking! Unfortunately, without the cadmium and lead, you can't get the luscious red this glaze produces. Life is short, good reds are hard to find ... I say take precautions and go for it! It's well worth it.

Karen in Gualala with great red pieces!



---------------------------------
Do you Yahoo!?
New DSL Internet Access from SBC & Yahoo!

Karen Shapiro on sun 29 sep 02


Asked about the Essence Red glaze: "I don't know what kind of cadmium they are using -- wonder if they'd tell"

The folks at Clayart are GREAT -- very helpful and forthright -- ask them and they will give you honest answers. Speak to Perry - he's the glaze tech I usually deal with.

Karen



---------------------------------
Do you Yahoo!?
New DSL Internet Access from SBC & Yahoo!

Janet Kaiser on mon 30 sep 02


>Am I missing something in this discussion? Raku firings are by definition
>not meant to hold liquid and are not food-safe.

Try telling all the people who use Raku pots and tea bowls on a daily
basis, that they do not hold liquid and are not food-safe! I think this may
be a cultural difference? Raku-type firing is being used for the effects
one can achieve, rather than to produce functional work as it was
originally conceived. Both are valid uses, but the one does not exclude the
other IMO.


Janet Kaiser

The Chapel of Art =95 Capel Celfyddyd
8 Marine Crescent, Criccieth LL52 0EA, Wales, UK
Tel: 01766-523570 URL: http://www.the-coa.org.uk

Brooks Ratledge on mon 30 sep 02


She was using bottled commercial cadmium red. This was back in the 1970's
and her kiln didn't have a vent system. She worked in that studio. They
know she breathed in fumes. Even though she is a neat (as in not messy)
potter, they thought she had also ingested some. Having seen what cadmium
can do to the body, I won't use it unless it's encapsulated. If you do try
it, use gloves, stay downwind from the kiln, anything you can do to keep
from getting it in your system. Patricia Harden
-----------------------------------------------------
Click here for Free Video!!
http://www.gohip.com/free_video/

-----Original Message-----
From: Pottery by Dai
To: CLAYART@LSV.CERAMICS.ORG
Date: Sunday, September 29, 2002 3:24 PM
Subject: Re: Red Glaze for Raku


>Patricia, could you give us some idea of how your friend "ingested"
>cadmium? Fumes? Through the skin? Any ideas? There are quite a few
>chemicals we use which are dangerous to us (i.e.chrome ox.) but if used
with
>all the precautions needed, shouldn't be worrisome. I'd like to try this
>red raku glaze, and want to know if I should use latex gloves when
applying,
>or not stand near or downwind of the kiln, or all of the above.
>Dai in Armstrong, BC
>
>dai@potterybydai.com
>potterybydai@telus.net
>nightfire@telus.net
>www.potterybydai.com
>
> Take your work seriously---take yourself lightly. Unknown
>
>___________________________________________________________________________
___
>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.

John Baymore on mon 30 sep 02



I'd like to try this
red raku glaze, and want to know if I should use latex gloves when
applying,
or not stand near or downwind of the kiln, or all of the above.



Check out the handling precautions and the TLV's or PEL for cadmium
compounds before you "dive in" to cadmium bearing materials. As to kiln
fumes...... you'd have to do air sampling to know how much is being
released into the effluent. Ditto to know actual dust concentrations. =


Also....... if you do use it and you sell in the USA or import into the
USA.... there are very specific FDA rules that you must comply with for
regular testing, recordkeeping, labeling, and so on. I think the state o=
f
California has it's own additional set..... they do for lead.

If you have employees, there are specific OSHA rules on cadmium use in th=
e
workplace.


Best,

..............................john

John Baymore
River Bend Pottery
22 Riverbend Way
Wilton, NH 03086 USA

603-654-2752 (s)
800-900-1110 (s)

JohnBaymore.com

JBaymore@compuserve.com

Ron Roy on mon 30 sep 02


Best to have your blood checked for both - best to know it's on the way
instead of an emergency situation.

Monona Rossol in her book says about Cadmium:

Contact to skin can result in: Irritation to skin, eyes and respitory
tract. Chronic exposure can ulcerate nasal septum and yellow teeth.

Acute inhalation of fumes can cause fatal illness whose early symptoms are
similar to metal fume fever (flu-like symptoms). Chronic exposure can cause
lung and kidney damage, anemia, and cancer. Some cadnium products are
insoluble but many pigment and ceramic grade cadmium products contain
enough soluble cadmium to be very hazardous. Has adverse reproductive
effects.

This is a bad one folks - in fact probably the worst we as potters get to
mess with - you can smell it when you take the lid off even the
encapsulated kind - thats cause some of the crystals are not complete -
take a look at the picture in their ads - you can see the imperfect
crystals.

>To all you who are worrying about using the Essence Red Raku glaze:
>
>I know I tend not to be as careful as I should, but I use this glaze all
>the time and am still alive and kicking! Unfortunately, without the
>cadmium and lead, you can't get the luscious red this glaze produces. Life
>is short, good reds are hard to find ... I say take precautions and go for
>it! It's well worth it.
>
>Karen in Gualala with great red pieces!

Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513