Ela Trent on sat 17 mar 01
Hello
Can anyone tell me if you can eat and drink out of anything with copper
carbonate which has been painted on top of the glaze before firing? Will it
poison the eater/drinker? (ie: mugs, bowls)
For that matter - if copper carbonate is in the glaze, does this also make
the pot poisonous to eat and drink out of.
The base glaze is a stoneware manly potash/china clay mix - no lead in
sight.
I know this is probably an easy one, but if anyone can enlighten me that
would be great.
Please reply to me at trentela@hotmail.com
Ta
Ela
_________________________________________________________________________
Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com.
Craig Martell on sat 17 mar 01
Ela asked:
>Can anyone tell me if you can eat and drink out of anything with copper
>carbonate which has been painted on top of the glaze before firing? Will it
>poison the eater/drinker? (ie: mugs, bowls)
Hi Ela:
There are toxicity issues with copper. The problem with overglaze washes
containing Cu is that it's impossible to determine the concentration of the
oxide on the surface of the glaze. You also need to have an idea of how
durable the glaze is. So, you need to know the molecular formula to even
venture a guess, and that's all it would be. The only way to make any sort
of determination here would be lab tests and then it would only be valid
for the piece tested. The next time you do a series of work you could load
the brush heavier and place more copper on the surface of the glaze.
It might be best if you brush the copper washes on areas where there isn't
a food contact issue. Also, the general rule is that if you go over 4%
copper in a glaze you run the risk of leaching more copper than is
recommended. Copper increases the solubility of glazes and it's my opinion
that one needs at least 3.0 moles of silica to 1.0 moles of flux and I
would include copper in the 1.0 value here. Even if this is determined,
you would still need to test.
regards, Craig Martell in Oregon
Dan Bowen on thu 17 oct 02
The copper carbonate I recently recieved was a darker green
than previous. From the archives I understand the paler version
(powder like) which I have the most experience is hydrated and is more
unpredictable with less copper. The darker green is more dence(granular)
and goes to the bottom of my glaze bucket. I have experimented with CMC,
bentonite and flocs. I do not have a ball mill. How do keep it in
suspention or do I need to find a suplier with the lighter green color.
Thanks
Dan Bowen
Eastville Virginia
East of the Chesapeake Bay
Jonathan Kirkendall on thu 17 oct 02
Dan,
I have copper carbonate from the same batch that you do - almost like very,
very fine sand. I was completely dubious, but I have to say that I haven't
seen an impact on my glazes. Even though after much stirring and after the
application I find what I would consider to be suspiciously large amounts of
the copper carb hanging out and gossiping in the bottom of the bucket, my
glazes are still the same green as the last batch.
Jonathan in DC
-----Original Message-----
From: Ceramic Arts Discussion List [mailto:CLAYART@LSV.CERAMICS.ORG]On
Behalf Of Dan Bowen
Sent: Thursday, October 17, 2002 8:19 AM
To: CLAYART@LSV.CERAMICS.ORG
Subject: copper carbonate
The copper carbonate I recently recieved was a darker green
than previous. From the archives I understand the paler version
(powder like) which I have the most experience is hydrated and is more
unpredictable with less copper. The darker green is more dence(granular)
and goes to the bottom of my glaze bucket. I have experimented with CMC,
bentonite and flocs. I do not have a ball mill. How do keep it in
suspention or do I need to find a suplier with the lighter green color.
Thanks
Dan Bowen
Eastville Virginia
East of the Chesapeake Bay
____________________________________________________________________________
__
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.
Dwiggins, Sandra (NIH/NCI) on thu 17 oct 02
Dan/Jonathan/Claybuds...
I just got off the phone with the person who manages our studio and we were
talking about this very thing. If bentonite, CMC, etc. doesn't work...then
what? We have a very nice stable green glaze for the students, but it is
difficult to keep that pesky green sand in suspension....
Jonathan...how do you keep the copper carbonate in suspension?
Suggestions????
Sandy
-----Original Message-----
From: Jonathan Kirkendall [mailto:Jonathan@MIRIAMSKITCHEN.ORG]
Sent: Thursday, October 17, 2002 12:20 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: copper carbonate
Dan,
I have copper carbonate from the same batch that you do - almost like very,
very fine sand. I was completely dubious, but I have to say that I haven't
seen an impact on my glazes. Even though after much stirring and after the
application I find what I would consider to be suspiciously large amounts of
the copper carb hanging out and gossiping in the bottom of the bucket, my
glazes are still the same green as the last batch.
Jonathan in DC
-----Original Message-----
From: Ceramic Arts Discussion List [mailto:CLAYART@LSV.CERAMICS.ORG]On
Behalf Of Dan Bowen
Sent: Thursday, October 17, 2002 8:19 AM
To: CLAYART@LSV.CERAMICS.ORG
Subject: copper carbonate
The copper carbonate I recently recieved was a darker green
than previous. From the archives I understand the paler version
(powder like) which I have the most experience is hydrated and is more
unpredictable with less copper. The darker green is more dence(granular)
and goes to the bottom of my glaze bucket. I have experimented with CMC,
bentonite and flocs. I do not have a ball mill. How do keep it in
suspention or do I need to find a suplier with the lighter green color.
Thanks
Dan Bowen
Eastville Virginia
East of the Chesapeake Bay
____________________________________________________________________________
__
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.
Lily Krakowski on thu 17 oct 02
Well, I repeat my earlier suggestion, to sieve, and grind the residue in a
mortar.
However. some glazes dislike being cold. And those really want to sit by
the stove at night and be warm, as in Summer. If your glaze is just
developing this settling out, maybe the poor baby is too cold.
Dwiggins, Sandra (NIH/NCI) writes:
> Dan/Jonathan/Claybuds...
> I just got off the phone with the person who manages our studio and we were
> talking about this very thing. If bentonite, CMC, etc. doesn't work...then
> what? We have a very nice stable green glaze for the students, but it is
> difficult to keep that pesky green sand in suspension....
>
> Jonathan...how do you keep the copper carbonate in suspension?
> Suggestions????
>
> Sandy
>
>
> -----Original Message-----
> From: Jonathan Kirkendall [mailto:Jonathan@MIRIAMSKITCHEN.ORG]
> Sent: Thursday, October 17, 2002 12:20 PM
> To: CLAYART@LSV.CERAMICS.ORG
> Subject: Re: copper carbonate
>
> Dan,
>
> I have copper carbonate from the same batch that you do - almost like very,
> very fine sand. I was completely dubious, but I have to say that I haven't
> seen an impact on my glazes. Even though after much stirring and after the
> application I find what I would consider to be suspiciously large amounts of
> the copper carb hanging out and gossiping in the bottom of the bucket, my
> glazes are still the same green as the last batch.
>
> Jonathan in DC
>
> -----Original Message-----
> From: Ceramic Arts Discussion List [mailto:CLAYART@LSV.CERAMICS.ORG]On
> Behalf Of Dan Bowen
> Sent: Thursday, October 17, 2002 8:19 AM
> To: CLAYART@LSV.CERAMICS.ORG
> Subject: copper carbonate
>
>
> The copper carbonate I recently recieved was a darker green
> than previous. From the archives I understand the paler version
> (powder like) which I have the most experience is hydrated and is more
> unpredictable with less copper. The darker green is more dence(granular)
> and goes to the bottom of my glaze bucket. I have experimented with CMC,
> bentonite and flocs. I do not have a ball mill. How do keep it in
> suspention or do I need to find a suplier with the lighter green color.
> Thanks
> Dan Bowen
> Eastville Virginia
> East of the Chesapeake Bay
>
> ____________________________________________________________________________
> __
> 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.
Lili Krakowski
P.O. Box #1
Constableville, N.Y.
(315) 942-5916/ 397-2389
Be of good courage....
Ababi on fri 18 oct 02
Stir
This is the magic word!
Ababi
---------- Original Message ----------
>Dan/Jonathan/Claybuds...
>I just got off the phone with the person who manages our studio and we were
>talking about this very thing. If bentonite, CMC, etc. doesn't work...then
>what? We have a very nice stable green glaze for the students, but it is
>difficult to keep that pesky green sand in suspension....
>Jonathan...how do you keep the copper carbonate in suspension?
>Suggestions????
>Sandy
>-----Original Message-----
>From: Jonathan Kirkendall [mailto:Jonathan@MIRIAMSKITCHEN.ORG]
>Sent: Thursday, October 17, 2002 12:20 PM
>To: CLAYART@LSV.CERAMICS.ORG
>Subject: Re: copper carbonate
>Dan,
>I have copper carbonate from the same batch that you do - almost like very,
>very fine sand. I was completely dubious, but I have to say that I haven't
>seen an impact on my glazes. Even though after much stirring and after the
>application I find what I would consider to be suspiciously large amounts of
>the copper carb hanging out and gossiping in the bottom of the bucket, my
>glazes are still the same green as the last batch.
>Jonathan in DC
>-----Original Message-----
>From: Ceramic Arts Discussion List [mailto:CLAYART@LSV.CERAMICS.ORG]On
>Behalf Of Dan Bowen
>Sent: Thursday, October 17, 2002 8:19 AM
>To: CLAYART@LSV.CERAMICS.ORG
>Subject: copper carbonate
>The copper carbonate I recently recieved was a darker green
> than previous. From the archives I understand the paler version
>(powder like) which I have the most experience is hydrated and is more
>unpredictable with less copper. The darker green is more dence(granular)
>and goes to the bottom of my glaze bucket. I have experimented with CMC,
>bentonite and flocs. I do not have a ball mill. How do keep it in
>suspention or do I need to find a suplier with the lighter green color.
>Thanks
>Dan Bowen
>Eastville Virginia
>East of the Chesapeake Bay
>____________________________________________________________________________
>__
>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.
Ilene Mahler on fri 18 oct 02
There are 2 ways ..1.put liquid dishwasher Detergent in the water or 2..use
cmc with really hot water..Ilene in Conn
----- Original Message -----
From: Dwiggins, Sandra (NIH/NCI)
To:
Sent: Thursday, October 17, 2002 1:07 PM
Subject: Re: copper carbonate
> Dan/Jonathan/Claybuds...
> I just got off the phone with the person who manages our studio and we
were
> talking about this very thing. If bentonite, CMC, etc. doesn't
work...then
> what? We have a very nice stable green glaze for the students, but it is
> difficult to keep that pesky green sand in suspension....
>
> Jonathan...how do you keep the copper carbonate in suspension?
> Suggestions????
>
> Sandy
>
>
> -----Original Message-----
> From: Jonathan Kirkendall [mailto:Jonathan@MIRIAMSKITCHEN.ORG]
> Sent: Thursday, October 17, 2002 12:20 PM
> To: CLAYART@LSV.CERAMICS.ORG
> Subject: Re: copper carbonate
>
> Dan,
>
> I have copper carbonate from the same batch that you do - almost like
very,
> very fine sand. I was completely dubious, but I have to say that I
haven't
> seen an impact on my glazes. Even though after much stirring and after
the
> application I find what I would consider to be suspiciously large amounts
of
> the copper carb hanging out and gossiping in the bottom of the bucket, my
> glazes are still the same green as the last batch.
>
> Jonathan in DC
>
> -----Original Message-----
> From: Ceramic Arts Discussion List [mailto:CLAYART@LSV.CERAMICS.ORG]On
> Behalf Of Dan Bowen
> Sent: Thursday, October 17, 2002 8:19 AM
> To: CLAYART@LSV.CERAMICS.ORG
> Subject: copper carbonate
>
>
> The copper carbonate I recently recieved was a darker green
> than previous. From the archives I understand the paler version
> (powder like) which I have the most experience is hydrated and is more
> unpredictable with less copper. The darker green is more dence(granular)
> and goes to the bottom of my glaze bucket. I have experimented with CMC,
> bentonite and flocs. I do not have a ball mill. How do keep it in
> suspention or do I need to find a suplier with the lighter green color.
> Thanks
> Dan Bowen
> Eastville Virginia
> East of the Chesapeake Bay
>
>
____________________________________________________________________________
> __
> 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.
Peter Cunicelli on fri 20 jan 12
>=3D20
> Hi everyone,
I'm a lurker and really appreciate the unbelievable amount of knowledge you=
a=3D
ll impart and have.
I'm a hand builder in Philadelphia. I've learned most of what I know throu=
g=3D
h trial and (lots of) error (or as i like to call them, lessons),as well as=
y=3D
ou and other people who are generous with their knowledge.
I've used commercial glazes up to this point, for the most part. I've laye=
r=3D
ed and had a lot of fun. Just like one should (lol), now that I feel confi=
d=3D
ent of the results, it's time to start from scratch and start formulating m=
y=3D
own glazes. So, I measured out 60 cups of 100g each of a base, alkaline c=
l=3D
ear and tested my colorants. I did ranges, based on the colorant. For exa=
m=3D
ple, the most cobalt I used was 10% and I know that's high. Rutile, higher=
.=3D
=3D20
With copper carbonate I went as high as 14%. This was just dipped on one l=
i=3D
ttle test tile. I really liked the results. It's glossy (flux property), l=
i=3D
ght green where it's thin and black/green where it's thicker. My work isn'=
t=3D
textured so I think this glaze would be really work well.
My next test is going mix another 100g and test on some small mugs I have i=
n=3D
the studio by brushing it on. I apply my glazes because I like the variat=
i=3D
on I get.
Can anyone tell me if the amount of the copper is too high or if I'll run i=
n=3D
to problems? I'm also open to any advice or comments anyone wants to make.=
=3D
I would love the guidance.
Thanks so much!
Peter
_____________________________________
...and now for something completely different
www.PeterCunicelli.com
William & Susan Schran User on fri 20 jan 12
On 1/20/12 11:20 AM, "Peter Cunicelli" wrote:
> With copper carbonate I went as high as 14%. This was just dipped on one
> little test tile. I really liked the results. It's glossy (flux property=
),
> light green where it's thin and black/green where it's thicker. My work =
isn't
> textured so I think this glaze would be really work well.
> My next test is going mix another 100g and test on some small mugs I have=
in
> the studio by brushing it on. I apply my glazes because I like the varia=
tion
> I get.
> Can anyone tell me if the amount of the copper is too high or if I'll run=
into
> problems? I'm also open to any advice or comments anyone wants to make. =
I
> would love the guidance.
Without running the glaze through a glaze calc program, it's difficult to
know if the base glaze is stable and functional even before any colorants
are added.
It is difficult to have copper remain stable in a glaze much above the 3-4%
added range, so I suspect using copper in the upper ranges you write about
would have a glaze where the copper might leach fairly easily from the
glaze, especially in contact with acidic foods, such as fruit juices. One
quick test is the lemon slice test. Lay the test tile horizontal, put a
slice of lemon on it, leave for 24 hours. If after 24 hours, you note any
color change where the lemon contacted the glaze, then that is a good
indication the glaze is leaching copper, something you probably don't want
to market to your customers.
You should get a copy of Mastering Cone 6 Glazes and carefully read through
the book. Here's the web site for more information:
http://www.masteringglazes.com/
John and Ron are often on Clayart helping folks with glaze/firing issues, s=
o
support them.
Have a look at John's web site: http://www.frogpondpottery.com/
On that site there is a link to glaze stability with recipes for glazes tha=
t
have been tested for stability. You should be able to find some glazes on
that site that will work for you.
Bill
--
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com
John Hesselberth on fri 20 jan 12
On Jan 20, 2012, at 11:20 AM, Peter Cunicelli wrote:
> Can anyone tell me if the amount of the copper is too high or if I'll =3D
run into problems? I'm also open to any advice or comments anyone wants =
=3D
to make. I would love the guidance.
Hi Peter,
I haven't found a glaze yet that will hold more than 5% copper carbonate =
=3D
without leaching a significant amount of it to the environment. And only =
=3D
well formulated ones will hold that much. If you are making functional =3D
work this can be a suitability-for-use problem. Your pots with 14% will =3D
almost certainly fade in a dishwasher or have the color removed by =3D
acidic foods. Try putting a juicy slice of lemon on one of your test =3D
tiles for a couple hours and then rinse and dry it. Or use the vinegar =3D
test as a screening test (3 days in vinegar without changing sheen or =3D
losing color will help you identify satisfactory functional glazes).
Mixing your own glazes can be a lot of fun. You just need to get to know =
=3D
your materials and what their strengths and limits are. Good luck!
Regards,
John
John Hesselberth
http://www.masteringglazes.com
http://www.frogpondpottery.com
Peter Cunicelli on fri 20 jan 12
John, Karin, William & Susan,
Thank you very much for the quick and helpful response. Thanks for the
encouragement too!
I've been doing this long enough that I should have remembered to tell you
that this is not for functional ware. Most of my work these days has been
one off pieces, like vases, urns, lidded vessels. But, I'm listening. I
am going to mix up a little more and try them on those mugs. I guess that
would lead you to believe that I'm doing functional work. Anyway, I'll
remember that this could cause copper to leach onto what comes in contact.
The color green this produced was amazing. I guess this is where the
challenge (and fun) is in trying to find this color with a combination of
glaze and colorants that is stable.
Karin, does my reputation precede me? J I really can be hard on myself.
But, I'm really looking forward to this part of my journey. I know I'm not
going to find a winning combination right off the bat. I'm doing this with
the expectation that I'm going to begin seeing what the colorants do, how
they react with each other, and finding a glaze that works well with my
work.
As far as pictures go, I'd be glad to do that. I'll create a page on my
site and point to that when it's done. I'm taking notes and documenting
what I do. I've learned just from working with commercial glazes that I
easily forget what I did a week after I did it. I'm also going to create a
photo album on my Studio Facebook page (link below) if anyone's interested
in looking at it there.
I also want you to know that I'm wearing a face mask and gloves when workin=
g
with the chemicals. I'm not that new to all this.
Thanks again!
Peter
--------------------------------------------------------------
...and now for something completely different.
Peter Cunicelli Homepage
Facebook
-----Original Message-----
From: owner-clayart@lsv.ceramics.org [mailto:owner-clayart@lsv.ceramics.org=
]
On Behalf Of John Hesselberth
Sent: Friday, January 20, 2012 12:36 PM
To: Peter Cunicelli
Cc: Clayart@LSV.CERAMICS.ORG
Subject: Re: Copper Carbonate
On Jan 20, 2012, at 11:20 AM, Peter Cunicelli wrote:
> Can anyone tell me if the amount of the copper is too high or if I'll run
into problems? I'm also open to any advice or comments anyone wants to
make. I would love the guidance.
Hi Peter,
I haven't found a glaze yet that will hold more than 5% copper carbonate
without leaching a significant amount of it to the environment. And only
well formulated ones will hold that much. If you are making functional work
this can be a suitability-for-use problem. Your pots with 14% will almost
certainly fade in a dishwasher or have the color removed by acidic foods.
Try putting a juicy slice of lemon on one of your test tiles for a couple
hours and then rinse and dry it. Or use the vinegar test as a screening tes=
t
(3 days in vinegar without changing sheen or losing color will help you
identify satisfactory functional glazes).
Mixing your own glazes can be a lot of fun. You just need to get to know
your materials and what their strengths and limits are. Good luck!
Regards,
John
John Hesselberth
http://www.masteringglazes.com
http://www.frogpondpottery.com
Edouard Bastarache on sat 21 jan 12
An exemple of an Oribe green glaze + the recipe.
Gis,
Edouard Bastarache
Spertesperantisto
Sorel-Tracy
Quebec
http://www.flickr.com/photos/30058682@N00/
http://edouardbastarache.blogspot.com/
http://smart2000.pagesperso-orange.fr/bloggs_edouard.htm
http://www.facebook.com/edouard.bastarache
http://www.flickr.com/photos/potier/102899351/in/photostream
----- Original Message -----
From: "Lee"
To:
Sent: Saturday, January 21, 2012 7:17 PM
Subject: Re: Copper Carbonate
On Sat, Jan 21, 2012 at 3:26 PM, wrote:
> Hi Peter,
>
> Just in addition to what others have said -
>
> That black you see is pure copper oxide on the surface - it happens
> because all that copper cannot be held in solution as the glaze cools
> - you can probably scrub it off.
>
>
In Japan with Oribe, they use muriatic acid to remove the "bloom" from
copper.
--
Lee Love in Minneapolis
http://mingeisota.blogspot.com/
"Ta tIr na n-=F3g ar chul an tI=97tIr dlainn trina ch=E9ile"=97that is, "T=
he land
of eternal youth is behind the house, a beautiful land fluent within
itself." -- John O'Donohue
Lee on sat 21 jan 12
On Sat, Jan 21, 2012 at 10:09 PM, Edouard Bastarache w=
=3D
rote:
> An exemple of an Oribe green glaze + the recipe.
Ken Matsuzaki example:
http://ceramicartsdaily.org/wp-content/uploads/2011/05/ken-matsuzaki-vase.j=
=3D
pg
I'll look for my recipe.
--
=3DA0Lee Love in Minneapolis
http://mingeisota.blogspot.com/
=3DA0"Ta tIr na n-=3DF3g ar chul an tI=3D97tIr dlainn trina ch=3DE9ile"=3D9=
7that is, =3D
"The
land of eternal youth is behind the house, a beautiful land fluent
within itself." -- John O'Donohue
ronroy@CA.INTER.NET on sat 21 jan 12
Hi Peter,
Just in addition to what others have said -
That black you see is pure copper oxide on the surface - it happens
because all that copper cannot be held in solution as the glaze cools
- you can probably scrub it off.
You get the same thing happening with oribe glazes and they only have
about 6% copper oxide.
RR
Quoting Peter Cunicelli :
> John, Karin, William & Susan,
>
>
>
> Thank you very much for the quick and helpful response. Thanks for the
> encouragement too!
>
>
>
> I've been doing this long enough that I should have remembered to tell yo=
u
> that this is not for functional ware. Most of my work these days has bee=
n
> one off pieces, like vases, urns, lidded vessels. But, I'm listening. =
I
> am going to mix up a little more and try them on those mugs. I guess tha=
t
> would lead you to believe that I'm doing functional work. Anyway, I'll
> remember that this could cause copper to leach onto what comes in contact=
.
>
>
>
> The color green this produced was amazing. I guess this is where the
> challenge (and fun) is in trying to find this color with a combination of
> glaze and colorants that is stable.
>
>
>
> Karin, does my reputation precede me? J I really can be hard on myself.
> But, I'm really looking forward to this part of my journey. I know I'm n=
ot
> going to find a winning combination right off the bat. I'm doing this wi=
th
> the expectation that I'm going to begin seeing what the colorants do, how
> they react with each other, and finding a glaze that works well with my
> work.
>
>
>
> As far as pictures go, I'd be glad to do that. I'll create a page on my
> site and point to that when it's done. I'm taking notes and documenting
> what I do. I've learned just from working with commercial glazes that I
> easily forget what I did a week after I did it. I'm also going to create=
a
> photo album on my Studio Facebook page (link below) if anyone's intereste=
d
> in looking at it there.
>
>
>
> I also want you to know that I'm wearing a face mask and gloves when work=
ing
> with the chemicals. I'm not that new to all this.
>
>
>
> Thanks again!
>
> Peter
>
>
>
> --------------------------------------------------------------
>
> ...and now for something completely different.
>
> Peter Cunicelli Homepage
>
> Facebook
>
>
>
> -----Original Message-----
> From: owner-clayart@lsv.ceramics.org [mailto:owner-clayart@lsv.ceramics.o=
rg]
> On Behalf Of John Hesselberth
> Sent: Friday, January 20, 2012 12:36 PM
> To: Peter Cunicelli
> Cc: Clayart@LSV.CERAMICS.ORG
> Subject: Re: Copper Carbonate
>
>
>
> On Jan 20, 2012, at 11:20 AM, Peter Cunicelli wrote:
>
>
>
>> Can anyone tell me if the amount of the copper is too high or if I'll ru=
n
> into problems? I'm also open to any advice or comments anyone wants to
> make. I would love the guidance.
>
>
>
> Hi Peter,
>
>
>
> I haven't found a glaze yet that will hold more than 5% copper carbonate
> without leaching a significant amount of it to the environment. And only
> well formulated ones will hold that much. If you are making functional wo=
rk
> this can be a suitability-for-use problem. Your pots with 14% will almost
> certainly fade in a dishwasher or have the color removed by acidic foods.
> Try putting a juicy slice of lemon on one of your test tiles for a couple
> hours and then rinse and dry it. Or use the vinegar test as a screening t=
est
> (3 days in vinegar without changing sheen or losing color will help you
> identify satisfactory functional glazes).
>
>
>
> Mixing your own glazes can be a lot of fun. You just need to get to know
> your materials and what their strengths and limits are. Good luck!
>
>
>
> Regards,
>
>
>
> John
>
>
>
>
>
> John Hesselberth
>
> http://www.masteringglazes.com
>
> http://www.frogpondpottery.com
>
Lee on sat 21 jan 12
On Sat, Jan 21, 2012 at 3:26 PM, wrote:
> Hi Peter,
>
> Just in addition to what others have said -
>
> That black you see is pure copper oxide on the surface - it happens
> because all that copper cannot be held in solution as the glaze cools
> - you can probably scrub it off.
>
>
In Japan with Oribe, they use muriatic acid to remove the "bloom" from
copper.
--
Lee Love in Minneapolis
http://mingeisota.blogspot.com/
"Ta tIr na n-=3DF3g ar chul an tI=3D97tIr dlainn trina ch=3DE9ile"=3D97tha=
t is, "T=3D
he land
of eternal youth is behind the house, a beautiful land fluent within
itself." -- John O'Donohue
ivor and olive lewis on sun 22 jan 12
Dear Peter Cunicelli,
We all start somewhere. You may find that your learning curve has fewer
errors if you were to visit your local library and select a few books to
read.
Since you are working with your hands you will find a kindred spirit in
Paulus Berensohn whose book "Finding One's Way With Clay. Pinched Pottery
and the Colour of Clay" may be inspiring.
Copper compounds have a long history of providing the colouring material fo=
r
ceramics and glassware. As many people who practice Raku found out two to
three decades ago excessive amounts of Copper chemicals in glazes or slips
gave wonderful effects and stunning lustred surfaces. Then, within a few
years then these beautiful surfaces reacted with the atmosphere,
deteriorating to the extent that the original values, both aesthetically an=
d
financially were lost.
Work done by Ron Roy and John Hesselberth on the stability of glazes raises
serious questions about the behaviour of Copper and its compounds in
Silicate Systems. My own opinion is that as an element Copper never behaves
as do other colourants when added to silicate systems. Copper seems to be
incapable of forming silicate compounds or of freely dissolving in molten
silicate mixtures as do Iron, Manganese and Cobalt.
Regards,
Ivor Lewis,
REDHILL,
South Australia
Peter Cunicelli on sun 22 jan 12
Hi RR,
Thanks for the info. Are the saturation points of various colorants listed
anywhere? I don't even know if saturation is the word I'm looking for. I
used to be able to find something like that for Mason Stains, but not now.
I tried looking up other glaze recipes to see if I could get an idea of how
CC and others are used and to what percentages. That's why I posted my
question. 14% CC seemed pretty high. I've definitely decided not to pursu=
e
any further testing with that percentage. I'll lower it and test with a
tiny bit of cobalt and maybe some rutile. Although, I am hoping to come up
with a semi translucent glaze.
For now, I'm going to slow down with the testing because I was asked for 5-=
7
pieces for a yearlong exhibition and I have a show coming up in March for
which I was going to use some of those pieces. So, more reading, while
curled up on the couch in front of the fire will be in order.
Peter
--------------------------------------------------------------
...and now for something completely different.
Peter Cunicelli Homepage
Facebook
-----Original Message-----
From: owner-clayart@lsv.ceramics.org [mailto:owner-clayart@lsv.ceramics.org=
]
On Behalf Of ronroy@ca.inter.net
Sent: Saturday, January 21, 2012 4:26 PM
To: Peter Cunicelli
Cc: Clayart@LSV.CERAMICS.ORG
Subject: Re: Copper Carbonate
Hi Peter,
Just in addition to what others have said -
That black you see is pure copper oxide on the surface - it happens
because all that copper cannot be held in solution as the glaze cools
- you can probably scrub it off.
You get the same thing happening with oribe glazes and they only have
about 6% copper oxide.
RR
Quoting Peter Cunicelli :
> John, Karin, William & Susan,
>
>
>
> Thank you very much for the quick and helpful response. Thanks for the
> encouragement too!
>
>
>
> I've been doing this long enough that I should have remembered to tell yo=
u
> that this is not for functional ware. Most of my work these days has bee=
n
> one off pieces, like vases, urns, lidded vessels. But, I'm listening.
I
> am going to mix up a little more and try them on those mugs. I guess tha=
t
> would lead you to believe that I'm doing functional work. Anyway, I'll
> remember that this could cause copper to leach onto what comes in contact=
.
>
>
>
> The color green this produced was amazing. I guess this is where the
> challenge (and fun) is in trying to find this color with a combination of
> glaze and colorants that is stable.
>
>
>
> Karin, does my reputation precede me? J I really can be hard on myself.
> But, I'm really looking forward to this part of my journey. I know I'm
not
> going to find a winning combination right off the bat. I'm doing this
with
> the expectation that I'm going to begin seeing what the colorants do, how
> they react with each other, and finding a glaze that works well with my
> work.
>
>
>
> As far as pictures go, I'd be glad to do that. I'll create a page on my
> site and point to that when it's done. I'm taking notes and documenting
> what I do. I've learned just from working with commercial glazes that I
> easily forget what I did a week after I did it. I'm also going to create
a
> photo album on my Studio Facebook page (link below) if anyone's intereste=
d
> in looking at it there.
>
>
>
> I also want you to know that I'm wearing a face mask and gloves when
working
> with the chemicals. I'm not that new to all this.
>
>
>
> Thanks again!
>
> Peter
>
>
>
> --------------------------------------------------------------
>
> ...and now for something completely different.
>
> Peter Cunicelli Homepage
>
> Facebook
>
>
>
> -----Original Message-----
> From: owner-clayart@lsv.ceramics.org
[mailto:owner-clayart@lsv.ceramics.org]
> On Behalf Of John Hesselberth
> Sent: Friday, January 20, 2012 12:36 PM
> To: Peter Cunicelli
> Cc: Clayart@LSV.CERAMICS.ORG
> Subject: Re: Copper Carbonate
>
>
>
> On Jan 20, 2012, at 11:20 AM, Peter Cunicelli wrote:
>
>
>
>> Can anyone tell me if the amount of the copper is too high or if I'll ru=
n
> into problems? I'm also open to any advice or comments anyone wants to
> make. I would love the guidance.
>
>
>
> Hi Peter,
>
>
>
> I haven't found a glaze yet that will hold more than 5% copper carbonate
> without leaching a significant amount of it to the environment. And only
> well formulated ones will hold that much. If you are making functional
work
> this can be a suitability-for-use problem. Your pots with 14% will almost
> certainly fade in a dishwasher or have the color removed by acidic foods.
> Try putting a juicy slice of lemon on one of your test tiles for a couple
> hours and then rinse and dry it. Or use the vinegar test as a screening
test
> (3 days in vinegar without changing sheen or losing color will help you
> identify satisfactory functional glazes).
>
>
>
> Mixing your own glazes can be a lot of fun. You just need to get to know
> your materials and what their strengths and limits are. Good luck!
>
>
>
> Regards,
>
>
>
> John
>
>
>
>
>
> John Hesselberth
>
> http://www.masteringglazes.com
>
> http://www.frogpondpottery.com
>
ronroy@CA.INTER.NET on sun 22 jan 12
Hi Peter,
I've been looking for a list but can't find one - but The Potters
Dictionary of Materials and Techniques by Frank and Janet Hamer has
the information you want - you just have to read the sections on the
various oxides to get the % of any oxide that will not stay dissolved
in a glaze.
Wonderful book in all aspects by the way - the best there is if you
want to understand what we need to know to get get the job done.
RR
Quoting Peter Cunicelli :
> Hi RR,
>
>
>
> Thanks for the info. Are the saturation points of various colorants list=
ed
> anywhere? I don't even know if saturation is the word I'm looking for. =
I
> used to be able to find something like that for Mason Stains, but not now=
.
>
>
>
> I tried looking up other glaze recipes to see if I could get an idea of h=
ow
> CC and others are used and to what percentages. That's why I posted my
> question. 14% CC seemed pretty high. I've definitely decided not to pur=
sue
> any further testing with that percentage. I'll lower it and test with a
> tiny bit of cobalt and maybe some rutile. Although, I am hoping to come =
up
> with a semi translucent glaze.
>
>
>
> For now, I'm going to slow down with the testing because I was asked for =
5-7
> pieces for a yearlong exhibition and I have a show coming up in March for
> which I was going to use some of those pieces. So, more reading, while
> curled up on the couch in front of the fire will be in order.
>
>
>
> Peter
>
>
>
> --------------------------------------------------------------
>
> ...and now for something completely different.
>
> Peter Cunicelli Homepage
>
> Facebook
>
>
>
> -----Original Message-----
> From: owner-clayart@lsv.ceramics.org [mailto:owner-clayart@lsv.ceramics.o=
rg]
> On Behalf Of ronroy@ca.inter.net
> Sent: Saturday, January 21, 2012 4:26 PM
> To: Peter Cunicelli
> Cc: Clayart@LSV.CERAMICS.ORG
> Subject: Re: Copper Carbonate
>
>
>
> Hi Peter,
>
>
>
> Just in addition to what others have said -
>
>
>
> That black you see is pure copper oxide on the surface - it happens
>
> because all that copper cannot be held in solution as the glaze cools
>
> - you can probably scrub it off.
>
>
>
> You get the same thing happening with oribe glazes and they only have
>
> about 6% copper oxide.
>
>
>
> RR
>
>
>
>
>
> Quoting Peter Cunicelli :
>
>
>
>> John, Karin, William & Susan,
>
>>
>
>>
>
>>
>
>> Thank you very much for the quick and helpful response. Thanks for the
>
>> encouragement too!
>
>>
>
>>
>
>>
>
>> I've been doing this long enough that I should have remembered to tell y=
ou
>
>> that this is not for functional ware. Most of my work these days has be=
en
>
>> one off pieces, like vases, urns, lidded vessels. But, I'm listening.
> I
>
>> am going to mix up a little more and try them on those mugs. I guess th=
at
>
>> would lead you to believe that I'm doing functional work. Anyway, I'll
>
>> remember that this could cause copper to leach onto what comes in contac=
t.
>
>>
>
>>
>
>>
>
>> The color green this produced was amazing. I guess this is where the
>
>> challenge (and fun) is in trying to find this color with a combination o=
f
>
>> glaze and colorants that is stable.
>
>>
>
>>
>
>>
>
>> Karin, does my reputation precede me? J I really can be hard on myself=
.
>
>> But, I'm really looking forward to this part of my journey. I know I'm
> not
>
>> going to find a winning combination right off the bat. I'm doing this
> with
>
>> the expectation that I'm going to begin seeing what the colorants do, ho=
w
>
>> they react with each other, and finding a glaze that works well with my
>
>> work.
>
>>
>
>>
>
>>
>
>> As far as pictures go, I'd be glad to do that. I'll create a page on my
>
>> site and point to that when it's done. I'm taking notes and documenting
>
>> what I do. I've learned just from working with commercial glazes that I
>
>> easily forget what I did a week after I did it. I'm also going to creat=
e
> a
>
>> photo album on my Studio Facebook page (link below) if anyone's interest=
ed
>
>> in looking at it there.
>
>>
>
>>
>
>>
>
>> I also want you to know that I'm wearing a face mask and gloves when
> working
>
>> with the chemicals. I'm not that new to all this.
>
>>
>
>>
>
>>
>
>> Thanks again!
>
>>
>
>> Peter
>
>>
>
>>
>
>>
>
>> --------------------------------------------------------------
>
>>
>
>> ...and now for something completely different.
>
>>
>
>> Peter Cunicelli Homepage
>
>>
>
>> Facebook
>
>>
>
>>
>
>>
>
>> -----Original Message-----
>
>> From: owner-clayart@lsv.ceramics.org
> [mailto:owner-clayart@lsv.ceramics.org]
>
>> On Behalf Of John Hesselberth
>
>> Sent: Friday, January 20, 2012 12:36 PM
>
>> To: Peter Cunicelli
>
>> Cc: Clayart@LSV.CERAMICS.ORG
>
>> Subject: Re: Copper Carbonate
>
>>
>
>>
>
>>
>
>> On Jan 20, 2012, at 11:20 AM, Peter Cunicelli wrote:
>
>>
>
>>
>
>>
>
>>> Can anyone tell me if the amount of the copper is too high or if I'll r=
un
>
>> into problems? I'm also open to any advice or comments anyone wants to
>
>> make. I would love the guidance.
>
>>
>
>>
>
>>
>
>> Hi Peter,
>
>>
>
>>
>
>>
>
>> I haven't found a glaze yet that will hold more than 5% copper carbonate
>
>> without leaching a significant amount of it to the environment. And only
>
>> well formulated ones will hold that much. If you are making functional
> work
>
>> this can be a suitability-for-use problem. Your pots with 14% will almos=
t
>
>> certainly fade in a dishwasher or have the color removed by acidic foods=
.
>
>> Try putting a juicy slice of lemon on one of your test tiles for a coupl=
e
>
>> hours and then rinse and dry it. Or use the vinegar test as a screening
> test
>
>> (3 days in vinegar without changing sheen or losing color will help you
>
>> identify satisfactory functional glazes).
>
>>
>
>>
>
>>
>
>> Mixing your own glazes can be a lot of fun. You just need to get to know
>
>> your materials and what their strengths and limits are. Good luck!
>
>>
>
>>
>
>>
>
>> Regards,
>
>>
>
>>
>
>>
>
>> John
>
>>
>
>>
>
>>
>
>>
>
>>
>
>> John Hesselberth
>
>>
>
>> http://www.masteringglazes.com
>
>>
>
>> http://www.frogpondpottery.com
>
>>
>
| |
|
