Vince Pitelka on sun 25 oct 09
Eileen de Rosas wrote:
"How would I be able to tell if it were Lithium Carb in the bag or not? Is
there a simple test?"
Eileen -
I do not know of a simple test, other than its performance. Apparently
lithium carb can be an irritant, but I certainly have never heard of anyone
feeling a burning sensation from immersing their hands in a
lithium-containing glaze, so that's why I said that there is reason for
concern. If this lithium were to deliver the same glaze results as what yo=
u
used before, that would pretty much verify that it is the real thing. But =
I
am not a chemist, so I cannot tell you of any specific test. Sorry I canno=
t
help further, but it sounds like you have made a wise decision to go with a
different supplier. Maybe Ron Roy, John Hesselberth, or one of the other
more chemically-minded list members will know of a more accurate test.
- Vince
Vince Pitelka
Appalachian Center for Craft
Tennessee Tech University
vpitelka@dtccom.net; wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka
Eileen de Rosas on sun 25 oct 09
Hi,
I am a lurker on this list, reading the digest when I have time, and always
learning something new, but never posting.
But I have run into a problem that I can't get my head around-----
Last week I purchased glaze chemicals from a supplier (who shall remain
nameless). I was in a bit of a rush since I needed to have the work ready
quickly. The glaze I was making was Jackie's ^04 Lowfire, in a rainbow of
colors. This glaze has a significant amount of Lithium Carbonate in it,
which I believe contributes to its waxy, satiny quality. (I know you guys
will tell me if I'm wrong about that).
Besides being expensive, Lithium Carbonate is sold in two grades at this
supplier, Fine and Coarse. I asked for fine since it had to go through the
glaze sieve. So I mixed up my 10 glazes, slaked them, and got ready to
sieve them the next day. As I was stirring them, I reached into the bucket
with, yes, an unglazed hand, which almost immediately began to sting.
Uh-oh.
Then, at the bottom, is this mass of sludge that will not go through the
sieve. Just will not. And it seems as though the oxides/colorants are all
mixed up with it.
I'm getting worried. I have to use my bare fingers to shove as much as I
can through the sieve. I end up with a lot colored sand in the bottom of
the sieve, which I end up dumping in the glaze because I can't let that muc=
h
not go into the glaze.
It is the same with each succeeding glaze. It takes me 3 times as long to
sieve these glazes, and everywhere I don't have gloves my skin is burned (o=
n
the upper elbow, above the gloves, say, as I mix).
I suspect it's either the Lithium Carb or the Flint, since I ordered these
and all the other ingredients have been on hand for some time with no
problems.
When I touch the small amount of dry Lithium left, it has the coarse grain
that I felt sieving the glazes. So maybe they packed the wrong kind at the
supplier.
The pots I made have large splotches of glassy color corresponding to the
slivers of coarse material that I left in the glaze. So maybe it was the
Flint?
In either case, I can't return the materials, it's too late now.
Is there any way I could grind these glazes without a ball mill? I'm tryin=
g
to think of some way to get those particles finer without one--I hate to
waste all that money and time.
Any ideas out there? I would really appreciate some help from this wise
list.
Thank you!
Eileen
James Freeman on sun 25 oct 09
Eileen...
Lithium carbonate can be a skin irritant to some folks. Use gloves if this
is a problem for you. Many would advise that one use gloves with all glaze=
s
regardless of skin sensitivity. Sensitive skin that has contacted lithium
carb should be washed with soap and water. One should not work any glaze
materials through a sieve with bare hands, if for no other reason than to
avoid abrasion. Use a stiff rubber spatula instead. Do a google search fo=
r
"msds lithium carbonate" to locate a material safety data sheet for all
dangers and precautions.
The "sand" in your sieve is indeed the lithium carb. Though most sources
list it as moderately soluble, for our purposes it should be thought of as
insoluble. Left to itself, the "sand" will pretty much never break down in
your glaze, and as you have noticed, it will take an eternity to work it
through a sieve.
Some suppliers sell materials they are scared of in granular form in an
attempt to avoid potential litigation, though they pretty much screw their
customers in so doing by shifting a lot of additional work onto their
shoulders. I have stopped ordering both barium and lithium from my main
supplier because they switched to the granular form. Both Bailey and U.S.
Pigment sell lithium carb in powdered form, which is what you want, and I a=
m
sure there are many other sources as well.
As to the glaze you have already mixed with the granular lithium, you have
several choices beyond finding a ball mill to run it through. First, you
could sit there for a very, very long time and work it through the sieve
with a spatula. You can grind the sandy sludge from the sieve with a morta=
r
and pestle. Slow work, but not as slow as trying to work it through the
sieve. For small amounts, an inexpensive rock tumbler makes a serviceable
ball mill. You can use the gritty mix as is, stirring frequently, and
celebrate the interesting surface it imparts. Lastly, though I have not
tried it myself, I am told that you can put the gritty glaze in an old
blender and "blend the sh*t out of it", using the blender as something of a
hammer mill. I am sure you will receive other good suggestions as well.
Good luck.
...James
James Freeman
"All I say is by way of discourse, and nothing by way of advice. I should
not speak so boldly if it were my due to be believed."
-Michel de Montaigne
http://www.jamesfreemanstudio.com
http://www.flickr.com/photos/jamesfreemanstudio/
http://www.jamesfreemanstudio.com/clayart/
On Sun, Oct 25, 2009 at 10:16 AM, Eileen de Rosas wrot=
e:
>
>
> Besides being expensive, Lithium Carbonate is sold in two grades at this
> supplier, Fine and Coarse. I asked for fine since it had to go through t=
he
> glaze sieve. So I mixed up my 10 glazes, slaked them, and got ready to
> sieve them the next day. As I was stirring them, I reached into the buck=
et
> with, yes, an unglazed hand, which almost immediately began to sting.
> Uh-oh.
>
> Then, at the bottom, is this mass of sludge that will not go through the
> sieve. Just will not. And it seems as though the oxides/colorants are a=
ll
> mixed up with it.
>
>
Vince Pitelka on sun 25 oct 09
Eileen de Rosas wrote:
"Besides being expensive, Lithium Carbonate is sold in two grades at this
supplier, Fine and Coarse. I asked for fine since it had to go through the
glaze sieve. So I mixed up my 10 glazes, slaked them, and got ready to
sieve them the next day. As I was stirring them, I reached into the bucket
with, yes, an unglazed hand, which almost immediately began to sting.
It is the same with each succeeding glaze. It takes me 3 times as long to
sieve these glazes, and everywhere I don't have gloves my skin is burned (o=
n
the upper elbow, above the gloves, say, as I mix)."
Eileen -
I would be worried about this, and it is not too late to confront the
supplier. There is no way that you could know about this before using some
of the materials, and at the least they should send you replacement
materials. I have been using lithium carbonate in Jaquie Rice's cone 04
glazes for 25 years, and have never experienced the stinging, burning effec=
t
you describe. I am concerned that they might have sent you something else
altogether. Have you mixed glazes with lithium carbonate before, and if so,
have you ever experienced similar effects?
- Vince
Vince Pitelka
Appalachian Center for Craft
Tennessee Tech University
vpitelka@dtccom.net; wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka
Eileen de Rosas on sun 25 oct 09
Vince,
Thanks for responding so quickly. I don't remember using a lot of Lithium
Carb before, as my lowfire experience has mostly been in majolica, and for
mid to high fire ranges I think the Lithium came from Spodumene. I did mix
up a bunch of tests of Jacqui's about a year ago, using the Lithium Carb
that I had bought from Bailey years (and I mean years!) ago. There were no
problems, and over this year I have really grown fond of the glazes, which
is why I went whole hog to make larger batches.
So--I've decide that I am not using that supplier anymore, convenient thoug=
h
they are, and be a bit more organized and thorough about planing and
purchasing materials. I actually don't want to deal with them anymore,
since they got the order wrong in other particulars anyway, and were so
helpful or concerned about it.
How would I be able to tell if it were Lithium Carb in the bag or not? Is
there a simple test?
Thanks again,
Eileen
On Sun, Oct 25, 2009 at 11:58 AM, Vince Pitelka wrote=
:
> Eileen de Rosas wrote:
> "Besides being expensive, Lithium Carbonate is sold in two grades at this
> supplier, Fine and Coarse. I asked for fine since it had to go through t=
he
> glaze sieve. So I mixed up my 10 glazes, slaked them, and got ready to
> sieve them the next day. As I was stirring them, I reached into the buck=
et
> with, yes, an unglazed hand, which almost immediately began to sting.
> It is the same with each succeeding glaze. It takes me 3 times as long t=
o
> sieve these glazes, and everywhere I don't have gloves my skin is burned
> (on
> the upper elbow, above the gloves, say, as I mix)."
>
> Eileen -
> I would be worried about this, and it is not too late to confront the
> supplier. There is no way that you could know about this before using so=
me
> of the materials, and at the least they should send you replacement
> materials. I have been using lithium carbonate in Jaquie Rice's cone 04
> glazes for 25 years, and have never experienced the stinging, burning
> effect
> you describe. I am concerned that they might have sent you something els=
e
> altogether. Have you mixed glazes with lithium carbonate before, and if s=
o,
> have you ever experienced similar effects?
> - Vince
>
> Vince Pitelka
> Appalachian Center for Craft
> Tennessee Tech University
> vpitelka@dtccom.net; wpitelka@tntech.edu
> http://iweb.tntech.edu/wpitelka
>
>
>
>
>
John Hesselberth on mon 26 oct 09
On Oct 26, 2009, at 12:29 AM, Vince Pitelka wrote:
> Maybe Ron Roy, John Hesselberth, or one of the other
> more chemically-minded list members will know of a more accurate test.
Hi Eileen,
Lithium carbonate melts at 618C (1144F). Not many of our other glaze
chemicals would melt that low. So you could set you kiln for 1200F
(kiln thermocouples are always a little off) and see if it melts. That
would not be certain, but it would be a pretty good indication.
Others may have a better way.
Regards,
John
Eileen de Rosas on mon 26 oct 09
Thank you for all the information!
Now I will go off and search for an old blender---it's too bad, I just got
rid of one a few months ago, never suspecting that I'd need it in the
pottery studio. And I'll keep my eye out for a rock tumbler--what an
ingenious idea.
And yes, I know I should be using gloves, and after the burns on my hand, I
did wear them.
This list is a great resource, and potters so good at sharing their
knowledge--what a great group of people.
I'll let you all know if the blender/mortar and pestle/rock tumbler works.
Eileen
On Sun, Oct 25, 2009 at 11:57 AM, James Freeman <
jamesfreemanstudio@gmail.com> wrote:
> Eileen...
>
> Lithium carbonate can be a skin irritant to some folks. Use gloves if th=
is
> is a problem for you. Many would advise that one use gloves with all gla=
zes
> regardless of skin sensitivity. Sensitive skin that has contacted lithiu=
m
> carb should be washed with soap and water. One should not work any glaze
> materials through a sieve with bare hands, if for no other reason than to
> avoid abrasion. Use a stiff rubber spatula instead. Do a google search =
for
> "msds lithium carbonate" to locate a material safety data sheet for all
> dangers and precautions.
>
> The "sand" in your sieve is indeed the lithium carb. Though most sources
> list it as moderately soluble, for our purposes it should be thought of a=
s
> insoluble. Left to itself, the "sand" will pretty much never break down =
in
> your glaze, and as you have noticed, it will take an eternity to work it
> through a sieve.
>
> Some suppliers sell materials they are scared of in granular form in an
> attempt to avoid potential litigation, though they pretty much screw thei=
r
> customers in so doing by shifting a lot of additional work onto their
> shoulders. I have stopped ordering both barium and lithium from my main
> supplier because they switched to the granular form. Both Bailey and U.S=
.
> Pigment sell lithium carb in powdered form, which is what you want, and I=
am
> sure there are many other sources as well.
>
> As to the glaze you have already mixed with the granular lithium, you hav=
e
> several choices beyond finding a ball mill to run it through. First, you
> could sit there for a very, very long time and work it through the sieve
> with a spatula. You can grind the sandy sludge from the sieve with a mor=
tar
> and pestle. Slow work, but not as slow as trying to work it through the
> sieve. For small amounts, an inexpensive rock tumbler makes a serviceabl=
e
> ball mill. You can use the gritty mix as is, stirring frequently, and
> celebrate the interesting surface it imparts. Lastly, though I have not
> tried it myself, I am told that you can put the gritty glaze in an old
> blender and "blend the sh*t out of it", using the blender as something of=
a
> hammer mill. I am sure you will receive other good suggestions as well.
>
> Good luck.
>
> ...James
>
> James Freeman
>
> "All I say is by way of discourse, and nothing by way of advice. I shoul=
d
> not speak so boldly if it were my due to be believed."
> -Michel de Montaigne
>
> http://www.jamesfreemanstudio.com
> http://www.flickr.com/photos/jamesfreemanstudio/
> http://www.jamesfreemanstudio.com/clayart/
>
>
>
>
> On Sun, Oct 25, 2009 at 10:16 AM, Eileen de Rosas wr=
ote:
>
>>
>>
>> Besides being expensive, Lithium Carbonate is sold in two grades at this
>> supplier, Fine and Coarse. I asked for fine since it had to go through
>> the
>> glaze sieve. So I mixed up my 10 glazes, slaked them, and got ready to
>> sieve them the next day. As I was stirring them, I reached into the
>> bucket
>> with, yes, an unglazed hand, which almost immediately began to sting.
>> Uh-oh.
>>
>> Then, at the bottom, is this mass of sludge that will not go through the
>> sieve. Just will not. And it seems as though the oxides/colorants are
>> all
>> mixed up with it.
>>
>>
>
L TURNER on mon 26 oct 09
John,
Eileen,
> Others may have a better way.
You might try a "flame test" . The flame test was one of the first
qualitative analytical tests to be run before the automated Atomic
Absorption tools became available. The Lithium will turn a bunsen
burner flame to red.
More about flame tests can be found at a number of chemistry websites.
Two are:
from About Chemistry:
How to Do a Flame Test & Interpret Results
http://chemistry.about.com/od/analyticalchemistry/a/flametest.htm
From Wikipedia, the free encyclopedia
Flame test
http://en.wikipedia.org/wiki/Flame_test
Both are quite informative. The About article is more step-by-step.
Regards
L. Turner
The Woodlands, TX
Bonnie Staffel on mon 26 oct 09
I had the same problem with some zinc that had clustered into hard small
lumps. I put about a half cup dry into an old Waring Blender, turned it =3D
on
high and the material became fine. I put it dry through my screen, =3D
returned
the larger particles to the blander again and was able to salvage the
material. Zinc likes to cluster from dampness I hear, and it was stored =3D
in
the basement for quite a long time. So if it is worth the time to do =3D
this,
wouldn't hurt to try.
Bonnie
http://webpages.charter.net/bstaffel/
http://vasefinder.com/bstaffelgallery1.html
DVD=3DA0 Throwing with Coils and Slabs
DVD=3DA0 Introduction to Wheel Work
Charter Member Potters Council
Veena Raghavan on mon 26 oct 09
Bonnie,
What a great idea. Never thought of that. Maybe this would work with
Cornwall Stone, which tends to clump. You are always amazing and I love rea=
ding
your posts. Also love your video Throwing with slabs and coils.
All the best.
Veena
In a message dated 10/26/2009 3:29:41 PM Eastern Daylight Time,
bstaffel@CHARTERMI.NET writes:
>
> I had the same problem with some zinc that had clustered into hard small
> lumps. I put about a half cup dry into an old Waring Blender, turned it o=
n
> high and the material became fine. I put it dry through my screen,
> returned
> the larger particles to the blander again and was able to salvage the
> material. Zinc likes to cluster from dampness I hear, and it was stored i=
n
> the basement for quite a long time. So if it is worth the time to do this=
,
> wouldn't hurt to try.
>
VeenaRaghavan@cs.com
ivor & olive lewis on tue 27 oct 09
Eileen de Rosas asks
"How would I be able to tell if it were Lithium Carb in the bag or not? Is
there a simple test?"
Alkali metals (Group 1 elements) and some Alkali Earths (Group 2
Elements)are well know for their ability to tint a Bunsen burner flame with
characteristic colours, especially if the sample is dampened with Dilute
Hydrochloric acid. This Flame Test is best done with Platinum wire but a
clean piece of Nichrome wire will do at a pinch.
Lithium compounds cause a characteristic Crimson flame.
Many compounds are contaminated with Sodium. This give a bright golden
Yellow.
I expect a full list to be available in Wikipedia.
A topic I would incorporate into any Ceramic Arts Course would include woul=
d
be the tests for identification of the basic elements we use.
Best regards,Ivor Lewis,
Redhill,
South Australia
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