Vince Pitelka on sat 2 jul 05
> I made up a test batch of Somebright Green, which contains Strontium
> Carbonate. A non-potter friend of mine said, "Oh fine, now your hair can
> really fall out."
Jean -
Please promptly go scold your friend for unnecessarily being an alarmist.
Strontium carbonate is non-toxic, and is the popular replacement for barium
carbonate. Barium carbonate is also harmless if properly used, but has
fallen victim to toxic scare.
Good luck with the Somebrite green.
- Vince
Vince Pitelka
Appalachian Center for Craft, Tennessee Technological University
Smithville TN 37166, 615/597-6801 x111
vpitelka@dtccom.net, wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka/
http://www.tntech.edu/craftcenter/
Jean Cochran on sat 2 jul 05
Hi Everyone,
Yesterday I had the pleasure of receiving gracious glaze help from Vince
Pitelka, Thank You Vince.
I made up a test batch of Somebright Green, which contains Strontium
Carbonate. A non-potter friend of mine said, "Oh fine, now your hair can
really fall out." Which leads me to this question. Do I need to handle
this ingredient with "kid gloves"? Normally, I do a combination of dipping
and spraying glazes; and normally I have my naked hands in the glaze; that
is sans rubber gloves. Of course, I wear a spray mask when spraying on
glazes.
Jean Wadsworth Cochran
www.foxhollowpottery.com
www.kycraft.ky.gov/craftcgi-bin/index.cgi?busid=186
John Hesselberth on sat 2 jul 05
On Saturday, July 2, 2005, at 07:54 PM, Jean Cochran wrote:
> , which contains Strontium
> Carbonate. A non-potter friend of mine said, "Oh fine, now your hair
> can
> really fall out." Which leads me to this question. Do I need to
> handle
> this ingredient with "kid gloves"?
Hi Jean,
No, your friend in confused. The strontium carbonate we potters use has
toxicity characteristics similar to calcium carbonate and it is not
radioactive. What your friend is thinking of is that Sr-90, a
radioactive form, is produced as a result of nuclear fusion. There are
trace amounts widely dispersed in the environment as a result of the
nuclear weapon testing done in the 1950s and 60s. Since atmospheric
testing was stopped the amount present in the environment is only about
1/4 of what it was back then (it has a half life of about 29 years).
Use your strontium carbonate and enjoy the results it is giving you.
Regards,
John
Edouard Bastarache Inc. on sun 3 jul 05
"Barium carbonate is also harmless if properly used, but has
fallen victim to toxic scare."
Right on Vince,
I really like the expression "toxic scare".
Later,
"Ils sont fous ces quebecois"
"They are insane these quebekers"
"Están locos estos quebequeses"
Edouard Bastarache
Irreductible Quebecois
Indomitable Quebeker
Sorel-Tracy
Quebec
edouardb@sorel-tracy.qc.ca
www.sorel-tracy.qc.ca/~edouardb/Welcome.html
http://www.ceramique.blogspot.com/
http://perso.wanadoo.fr/smart2000/index.htm
http://www.digitalfire.com/education/toxicity/
Snail Scott on sun 3 jul 05
At 07:54 PM 7/2/2005 -0400, you wrote:
>...I made up a test batch of Somebright Green, which contains Strontium
>Carbonate. A non-potter friend of mine said, "Oh fine, now your hair can
>really fall out."
I've discovered that for most people, the name
strontium brings to mind only its radioactive
isotope form. Even technically-savvy folks fall
into this habit of thought. (Maybe even more than
most.) Had a physicist darn near drop over from
shock when he saw me trot along home from my
supplier with a brown paper bag labeled 'strontium
carbonate' under my arm. He swore it must be
radioactive until he looked it up in a chemical
dictionary and admitted I was right: it was OK
stuff.
Strontium carbonate is a relatively innocuous
material, requiring only the common-sense
protections that we should use for all glaze
mixing. It is NOT radioactive. (If it was, we
would have pay a lot more for it!) ;)
-Snail
Bob Hanlin on tue 5 jul 05
I'm ain't sayin' who my prof was....but when I asked him about the BARIUM problems. His response was something like,
"Well, Bob, how many people have you heard of dying from barium?". I said something like, "Thanks" and forgot about it.
I'm alive.................for now..............
Note: I never did use much barium, how about you?
Bob
pdp1@EARTHLINK.NET on wed 6 jul 05
Hi Bob,
I think the Barium part is after they die, not before...
...least, thats how I heard it spoke of...
Phil
el ve
----- Original Message -----
From: "Bob Hanlin"
> I'm ain't sayin' who my prof was....but when I asked him about the BARIUM
problems. His response was something like,
> "Well, Bob, how many people have you heard of dying from barium?". I said
something like, "Thanks" and forgot about it.
>
> I'm alive.................for now..............
>
> Note: I never did use much barium, how about you?
>
> Bob
Ron Roy on wed 6 jul 05
Hi Bob,
I never used much - one pretty glaze by Mari Woo - in college - a yellow -
it would have been even better with Strontium.
I remember working on some glazes - getting the barium out - the iron
glazes all looked better - not so with the copper and cobalt.
I see lots of white glazes with some barium in them - complete waste of
money of course.
When subbing in Strontium - you need only 3/4 the amount of Strontium - in
other words its a sronger flux gram for gram - and - because you need less
- and the expansion is about the same as Barium - you lower expansion -
handy when dealing with crazing.
Strontium, Barium and Calcium are all close in the periodic table - they
have much in common. Calcium however is cheap and there are no toxicity
issues.
RR
>I'm ain't sayin' who my prof was....but when I asked him about the BARIUM
>problems. His response was something like,
>"Well, Bob, how many people have you heard of dying from barium?". I said
>something like, "Thanks" and forgot about it.
>
>I'm alive.................for now..............
>
>Note: I never did use much barium, how about you?
>
>Bob
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
Vince Pitelka on thu 7 jul 05
> Woo yellow is one of our stable cone 10 glazes
OOPS! Sorry Ron. When I wrote that, I meant that it is in our stable of
glazes - it is one of our stock glazes. It is a dry matt, and no way could
it be considered a stable glaze. My appologies if I misled anyone;
- Vince
Vince Pitelka
Appalachian Center for Craft, Tennessee Technological University
Smithville TN 37166, 615/597-6801 x111
vpitelka@dtccom.net, wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka/
http://www.tntech.edu/craftcenter/
Vince Pitelka on thu 7 jul 05
> I never used much - one pretty glaze by Mari Woo - in college - a yellow -
> it would have been even better with Strontium.
Ron -
Woo yellow is one of our stable cone 10 glazes, and it is one of the barium
glazes that we have held on to, because it is so beautiful. It is clearly
marked "NOT FOR FOOD CONTACT SURFACES."
You say "it would have been even better with strontium?" How so? I'll
certainly try it, but I'd love to know your theories on barium in iron
glazes.
I do not feel any compulsion to eliminate barium from our glaze lab, but
whenever I can get a glaze to perform as well or better with strontium, I'd
be crazy not to make the switch.
Thanks -
- Vince
Vince Pitelka
Appalachian Center for Craft, Tennessee Technological University
Smithville TN 37166, 615/597-6801 x111
vpitelka@dtccom.net, wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka/
http://www.tntech.edu/craftcenter/
Ron Roy on fri 8 jul 05
Hi Vince,
Thanks for the clarification on the word "stable" as you used it in this
context. You would have thought I would have jumped right on that but I
took it to mean it was one of the glazes you keep mixed up.
Always a shocker when you re read and see something like that - been there
many times.
I was working on some glaze for someone - many years ago - they were high
barium glazes and I was converting them to strontium. I can't remember just
how the glazes with iron looked better with Strontium - I do remember that
I liked them a lot better - it was not a subtle thing - warmer and smoother
is my faint recollection. I occures to me that it might be darker and so -
may need less iron. Now that I am thinking about it - perhaps rutile would
be interesting - a warm old bone colour that would take iron decoration in
a spectacular way.
I just made up a 20% Barium glaze in my glaze program - to see how much
Strontium you need to replace it - 3/4 exactly. So for 20 Barium sub in 15
strontium.
If I had more time I would do a line blend between the two versions - just
to see exactly what the effect would be on iron when lowering the barium
and increasing the strontium.
I would also be interested to know if the 50/50 mixture was noticeably more
melted than the parents.
I don't think I have a theory about iron and strontium - but based on that
experience and others - I do know that colouring oxides work differently
with certain base glazes. It is an area that needs more work in my opinion.
Tin has a beneficial effect with iron as well - at least to me.
>Ron -
>Woo yellow is one of our stable cone 10 glazes, and it is one of the barium
>glazes that we have held on to, because it is so beautiful. It is clearly
>marked "NOT FOR FOOD CONTACT SURFACES."
>
>You say "it would have been even better with strontium?" How so? I'll
>certainly try it, but I'd love to know your theories on barium in iron
>glazes.
>
>I do not feel any compulsion to eliminate barium from our glaze lab, but
>whenever I can get a glaze to perform as well or better with strontium, I'd
>be crazy not to make the switch.
>Thanks -
>- Vince
>
>Vince Pitelka
>Appalachian Center for Craft, Tennessee Technological University
>Smithville TN 37166, 615/597-6801 x111
>vpitelka@dtccom.net, wpitelka@tntech.edu
>http://iweb.tntech.edu/wpitelka/
>http://www.tntech.edu/craftcenter/
>
>______________________________________________________________________________
>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.
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
Fred Hagen on sat 9 jul 05
Vince, would you care to share the recipe for the Woo Yellow that you speak of. I attended a week at your facility last year but don't remember getting the recipe.
Thanks Fred Hagen
Vince Pitelka wrote:
> I never used much - one pretty glaze by Mari Woo - in college - a yellow -
> it would have been even better with Strontium.
Ron -
Woo yellow is one of our stable cone 10 glazes, and it is one of the barium
glazes that we have held on to, because it is so beautiful. It is clearly
marked "NOT FOR FOOD CONTACT SURFACES."
You say "it would have been even better with strontium?" How so? I'll
certainly try it, but I'd love to know your theories on barium in iron
glazes.
I do not feel any compulsion to eliminate barium from our glaze lab, but
whenever I can get a glaze to perform as well or better with strontium, I'd
be crazy not to make the switch.
Thanks -
- Vince
Vince Pitelka
Appalachian Center for Craft, Tennessee Technological University
Smithville TN 37166, 615/597-6801 x111
vpitelka@dtccom.net, wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka/
http://www.tntech.edu/craftcenter/
______________________________________________________________________________
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.
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