Megan Ratchford on tue 23 apr 02
Hey Bill!
Had the same kind of Cu carb come into the studio. Strange grass green,
but about the same consistancy. About swallowed my tongue when I saw the
glaze after a student made it. Thought our Oribe had been colored with
chrome!!
So far I haven't seen any difference in the glazes either.
Megan
----- Original Message -----
From: "william schran"
To:
Sent: Tuesday, April 23, 2002 5:47 PM
Subject: funky copper carbonate
> Last bag of copper carbonate I got was very different than what I've
> gotten in the past. Had always gotten pale green fine powder (fine
> like flour). This last batch was grass green, fairly intense color,
> seemed to be a bit more granular than powdery and larger particles
> would settle out of the glaze rather easy. Seems to produce same
> color as older batches. Anybody come across anything like this?
> Had also gotten some cobalt carbonate a while back that was VERY
> light and fluffy. seemed to require twice as much by volume to get
> the same weight as previous batches of cobalt. Weird stuff.
> Bill
>
>
____________________________________________________________________________
__
> 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.
william schran on tue 23 apr 02
Last bag of copper carbonate I got was very different than what I've
gotten in the past. Had always gotten pale green fine powder (fine
like flour). This last batch was grass green, fairly intense color,
seemed to be a bit more granular than powdery and larger particles
would settle out of the glaze rather easy. Seems to produce same
color as older batches. Anybody come across anything like this?
Had also gotten some cobalt carbonate a while back that was VERY
light and fluffy. seemed to require twice as much by volume to get
the same weight as previous batches of cobalt. Weird stuff.
Bill
Ababi on wed 24 apr 02
Hello Bill
My good and kind supplier whom I work with the last 3 years ( out of
six in ceramics), has the same copper carbonate. I agree with you, it
is not as easy to use as the other kind. You might have to use more CMC
or stir the glaze better, yet it works the same.
Ababi
---------- Original Message ----------
>Last bag of copper carbonate I got was very different than what I've
>gotten in the past. Had always gotten pale green fine powder (fine
>like flour). This last batch was grass green, fairly intense color,
>seemed to be a bit more granular than powdery and larger particles
>would settle out of the glaze rather easy. Seems to produce same
>color as older batches. Anybody come across anything like this?
>Had also gotten some cobalt carbonate a while back that was VERY
>light and fluffy. seemed to require twice as much by volume to get
>the same weight as previous batches of cobalt. Weird stuff.
>Bill
>________________________________________________________________________
>______
>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.
Marni Turkel on wed 24 apr 02
Bill,
For the last 8 or 9 years I have been using a lot of copper carbonate
(buy it in 50 lb bags) and have noticed significant differences in
the color of the product in the bag that may or may not result in
differences in the color of the fired glaze. I have had some batches
that make the glaze like pudding and require the use of a
deflocculent. I have not encountered differences in the particle size
that I've noticed. I accept variation over time as a part of ceramics
and make necessary adjustments. Different sources process things
differently, but irregularities in particle size strike me as a
processing problem and not something I have to adjust to. I'd show it
to my supplier and have it replaced.
Marni
>Last bag of copper carbonate I got was very different than what I've
>gotten in the past. Had always gotten pale green fine powder (fine
>like flour). This last batch was grass green, fairly intense color,
>seemed to be a bit more granular than powdery and larger particles
>would settle out of the glaze rather easy. Seems to produce same
>color as older batches. Anybody come across anything like this?
>Had also gotten some cobalt carbonate a while back that was VERY
>light and fluffy. seemed to require twice as much by volume to get
>the same weight as previous batches of cobalt. Weird stuff.
>Bill
--
Marni Turkel
Stony Point Ceramic Design
2080 Llano Rd 1B
Santa Rosa, CA 95407
Phone: 707-579-5567
Fax: 707-579-1116
http://www.marniturkel.com
David Hewitt on thu 25 apr 02
Ababi,
Would your good and kind supplier be agreeable to providing you with an
analysis, chemical and physical, of this material?
I ask this as I have for sometime felt that the pottery supply business
is very remise when it comes to such matters for the craft potter. A
large concern would insist on such information as a matter of routine
for the acceptance of any supply, but we as potters are expected to
accept whatever is put in front of us.
The same question applies to so many of the materials we use, not just
copper carbonate. I have recently seen similar comments about cobalt
oxide and a few years back I report on my own findings regarding black
iron oxide. At that time I also raised this general issue and suggested
hat we should all insist on such analyses. My own supplier, Bath
Potters' Supplies, will do this if I ask for it, but it is not routinely
available unless specially requested.
If enough of us kept asking for such data, perhaps it would become more
generally available and it could give us the answer to a lot of
problems.
David
In message , Ababi writes
>Hello Bill
>My good and kind supplier whom I work with the last 3 years ( out of
>six in ceramics), has the same copper carbonate. I agree with you, it
>is not as easy to use as the other kind. You might have to use more CMC
>or stir the glaze better, yet it works the same.
>Ababi
>---------- Original Message ----------
>
>>Last bag of copper carbonate I got was very different than what I've
>>gotten in the past. Had always gotten pale green fine powder (fine
>>like flour). This last batch was grass green, fairly intense color,
>>seemed to be a bit more granular than powdery and larger particles
>>would settle out of the glaze rather easy. Seems to produce same
>>color as older batches. Anybody come across anything like this?
>>Had also gotten some cobalt carbonate a while back that was VERY
>>light and fluffy. seemed to require twice as much by volume to get
>>the same weight as previous batches of cobalt. Weird stuff.
>>Bill
>
>>________________________________________________________________________
>>______
>>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.
--
David Hewitt
David Hewitt Pottery ,
7 Fairfield Road, Caerleon, Newport,
South Wales, NP18 3DQ, UK. Tel:- +44 (0) 1633 420647
FAX:- +44 (0) 870 1617274
Web site http://www.dhpot.demon.co.uk
Ababi on thu 25 apr 02
Hello David.
This is a painful subject. My main suppliers indeed are kind people.
They bring me they supply to my studio and very reliable and patient.
. A potter who worked for another main supplier, told me once, I was
the only costumer that asked for analysis.
That potter has an old Dos Insight. He could not tell me of other
potters he knew that used software yet as a software user he could
understand why I wanted the analysis.
My good and kind supplier rarely gives me analysis.
Sometimes I give him the analysis.
To remind you David you had given me the analysis of the ball clay: AK
and the kaolin: CC31 I found there names on the bills.
Sometimes I write to Steve mills too.
I learned another way, to ask what is written on the sack and find out
myself!
In a country that has some excellent chemical factories of paint,
medical and more, the potter cannot find a real analysis of a material,
unless he is very stubborn patience well connected and better
a clayarter.
Once I asked the ECC for an analysis. They forward my letter to their
agent in Israel, who told me that for 3 sacks a year he would not give
me the analysis ( or even to the supplier that kept that kaolin)
There are more stories, but as I delete too long letters I shall delete
my next words.
Ababi Sharon
Kibbutz Shoval- Israel
Glaze addict
ababisha@shoval.org.il
http://members4.clubphoto.com/ababi306910/
http://www.milkywayceramics.com/cgallery/asharon.htm
---------- Original Message ----------
>Ababi,
>Would your good and kind supplier be agreeable to providing you with an
>analysis, chemical and physical, of this material?
>I ask this as I have for sometime felt that the pottery supply business
>is very remise when it comes to such matters for the craft potter. A
>large concern would insist on such information as a matter of routine
>for the acceptance of any supply, but we as potters are expected to
>accept whatever is put in front of us.
>The same question applies to so many of the materials we use, not just
>copper carbonate. I have recently seen similar comments about cobalt
>oxide and a few years back I report on my own findings regarding black
>iron oxide. At that time I also raised this general issue and suggested
>hat we should all insist on such analyses. My own supplier, Bath
>Potters' Supplies, will do this if I ask for it, but it is not routinely
>available unless specially requested.
>If enough of us kept asking for such data, perhaps it would become more
>generally available and it could give us the answer to a lot of
>problems.
>David
>In message , Ababi writes
>>Hello Bill
>>My good and kind supplier whom I work with the last 3 years ( out of
>>six in ceramics), has the same copper carbonate. I agree with you, it
>>is not as easy to use as the other kind. You might have to use more CMC
>>or stir the glaze better, yet it works the same.
>>Ababi
>>---------- Original Message ----------
>>
>>>Last bag of copper carbonate I got was very different than what I've
>>>gotten in the past. Had always gotten pale green fine powder (fine
>>>like flour). This last batch was grass green, fairly intense color,
>>>seemed to be a bit more granular than powdery and larger particles
>>>would settle out of the glaze rather easy. Seems to produce same
>>>color as older batches. Anybody come across anything like this?
>>>Had also gotten some cobalt carbonate a while back that was VERY
>>>light and fluffy. seemed to require twice as much by volume to get
>>>the same weight as previous batches of cobalt. Weird stuff.
>>>Bill
>>
>>>______________________________________________________________________
>__
>>>______
>>>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.
>--
>David Hewitt
>David Hewitt Pottery ,
>7 Fairfield Road, Caerleon, Newport,
>South Wales, NP18 3DQ, UK. Tel:- +44 (0) 1633 420647
>FAX:- +44 (0) 870 1617274
>Web site http://www.dhpot.demon.co.uk
>________________________________________________________________________
>______
>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.
| |
|
