edwin gould on mon 22 nov 99
I TRIED ACRYLIC SPRAY AFTER A BEAUTIFUL BLUE AND RED FROM MOLLYS BLANDING
GLAZE; the colors disappeared. Any suggestions?
ababy sharon on tue 23 nov 99
Hi!
In the next time try pastels and charcoal's fixative or paraffin oil.
...May be you applied too thick? If you really like the acrylic, try on one
work, thin layer of gloss medium, I would do it with a sable brush to feel
what I am doing. The some with Matt (silky) medium on another work (or test
vessel)
Ababi
----- Original Message -----
From: edwin gould
To:
Sent: Monday, November 22, 1999 05:51
Subject: Preserving Raku finishes ACRYLIC FAILS
> ----------------------------Original message----------------------------
> I TRIED ACRYLIC SPRAY AFTER A BEAUTIFUL BLUE AND RED FROM MOLLYS BLANDING
> GLAZE; the colors disappeared. Any suggestions?
>
Charlie and Linda on tue 23 nov 99
edwin gould wrote:
>
> ----------------------------Original message----------------------------
> I TRIED ACRYLIC SPRAY AFTER A BEAUTIFUL BLUE AND RED FROM MOLLYS BLANDING
> GLAZE; the colors disappeared. Any suggestions?
Copper glazes change colors when coated with sealers due to the change
in the light refraction. Don't know how to stop that. Using sealers
did change all the copper colors for us and it did slow the fading of
the glaze.
But....I hate to tell you the news.....After 15 years of thinking that
I'd found the holy grail of copper lusters, you know, the one that won't
fade....
I don't know of a way to "perserve" the raku copper luster finish. I
chased copper matts for years and finally "won" just to loose. Once I
learned the tricky process of firing copper matts the next year I
learned that they all fade!!!!! Learned to fire Seth's Luster, Copper
Sand, Hawaiian Blue(and learned how to spell Hawaiian in the process),
Multi Colored Sand, etc.... They are all dying out. Did a bit of
dabbling in the "modified" copper glazes that weren't supposed to fade
and the few that worked died even faster.
The bottom line is that copper matt and copper lusters are subject to
oxidation. Either this week, month, year, or next few years it will
fade. The acrylic, the sealers, they may help slow it down but it's a
done deal.
I finally gave them up and moved on. It would have been easier to give
up coffee and beer as copper matts and lusters. It was putting food on
the table. We thought that we couldn't make it with out the "flash".
Well, we were wrong. Giving up copper matts/lusters drove us to
expriement with pit firing which lead to sagger firing and terra sig.
Now our income has increased 3x.
(Good golly, this sounds like an AA meeting.....)
If you are going to sell copper matts and lusters you are going to have
to ask yourself some hard questions.... How would you like to face that
costomer in two years. Are you going to feel proud of your two year old
work fading to gun metal gray or pea soup green or will you feel like
ducking and running? Hmm... There are several people that I'd not like
to meet.
The really great news is there is life without these glazes. Flash
sells mediocre pots and great pots alike to people that like flash. (I
like a little flash, too.) But good pots will sell themselves without
the copper flash and we ended up growing and learning alot in the
process.
Do what you have to do but coppers and all of us won't be here for ever.
Ok, folks, start shooting at the messenger.
Charlie Riggs
PS-Hey, Tom Buck.. Jump in here and give them a different view!
Lynne Berman on tue 23 nov 99
Try Jasco tile sealant, or perhaps other brands work as well. This tip comes
from a workshop by James Makins. The stuff also stops salt from eating up the
clay.
Lynne Berman in downtown Philadelphia
Robert Santerre on wed 24 nov 99
The automotive paint manufactures make a primer paint that prevents rusting
(oxidation). Don't know how it works chemically, but it does work to prevent
rusting of metal surfaces. I wonder if it would work for preventing copper
oxidation? I'm not sure if the primer is made in a "clear" version. The one
I've used was black. I got it at a Sherwin Williams store specializing in
automotive paints.
I know copper metal oxidation is preventable. Home builders put up copper
flashing on homes. That flashing can retain its copper appearance (doesn't
turn green) for years. How is this material treated?
Bob
rfsanterre@iquest.net
////////////////////////////////////////////////////////////////////////////////
Charlie and Linda wrote:
> ----------------------------Original message----------------------------
> edwin gould wrote:
> >
> > ----------------------------Original message----------------------------
> > I TRIED ACRYLIC SPRAY AFTER A BEAUTIFUL BLUE AND RED FROM MOLLYS BLANDING
> > GLAZE; the colors disappeared. Any suggestions?
>
> Copper glazes change colors when coated with sealers due to the change
> in the light refraction. Don't know how to stop that. Using sealers
> did change all the copper colors for us and it did slow the fading of
> the glaze.
>
> But....I hate to tell you the news.....After 15 years of thinking that
> I'd found the holy grail of copper lusters, you know, the one that won't
> fade....
>
> I don't know of a way to "perserve" the raku copper luster finish. I
> chased copper matts for years and finally "won" just to loose. Once I
> learned the tricky process of firing copper matts the next year I
> learned that they all fade!!!!! Learned to fire Seth's Luster, Copper
> Sand, Hawaiian Blue(and learned how to spell Hawaiian in the process),
> Multi Colored Sand, etc.... They are all dying out. Did a bit of
> dabbling in the "modified" copper glazes that weren't supposed to fade
> and the few that worked died even faster.
>
> The bottom line is that copper matt and copper lusters are subject to
> oxidation. Either this week, month, year, or next few years it will
> fade. The acrylic, the sealers, they may help slow it down but it's a
> done deal.
>
> I finally gave them up and moved on. It would have been easier to give
> up coffee and beer as copper matts and lusters. It was putting food on
> the table. We thought that we couldn't make it with out the "flash".
> Well, we were wrong. Giving up copper matts/lusters drove us to
> expriement with pit firing which lead to sagger firing and terra sig.
> Now our income has increased 3x.
>
> (Good golly, this sounds like an AA meeting.....)
>
> If you are going to sell copper matts and lusters you are going to have
> to ask yourself some hard questions.... How would you like to face that
> costomer in two years. Are you going to feel proud of your two year old
> work fading to gun metal gray or pea soup green or will you feel like
> ducking and running? Hmm... There are several people that I'd not like
> to meet.
>
> The really great news is there is life without these glazes. Flash
> sells mediocre pots and great pots alike to people that like flash. (I
> like a little flash, too.) But good pots will sell themselves without
> the copper flash and we ended up growing and learning alot in the
> process.
>
> Do what you have to do but coppers and all of us won't be here for ever.
>
> Ok, folks, start shooting at the messenger.
>
> Charlie Riggs
>
> PS-Hey, Tom Buck.. Jump in here and give them a different view!
Marcia Selsor on thu 25 nov 99
I have an ongoing test in my back yards that is eight years old. The
acylic LIquid polymer medium painted over the copper luster glaze did
prevent oxidization. What more can I say.? I painted it over "Reynolds
Wrap". The stripe where it was painted stayed coppery and the rest
turned green.
Marcia Selsor
in Billings, Montana
Robert Santerre wrote:
>
> ----------------------------Original message----------------------------
> The automotive paint manufactures make a primer paint that prevents rusting
> (oxidation). Don't know how it works chemically, but it does work to prevent
> rusting of metal surfaces. I wonder if it would work for preventing copper
> oxidation? I'm not sure if the primer is made in a "clear" version. The one
> I've used was black. I got it at a Sherwin Williams store specializing in
> automotive paints.
>
> I know copper metal oxidation is preventable. Home builders put up copper
> flashing on homes. That flashing can retain its copper appearance (doesn't
> turn green) for years. How is this material treated?
>
> Bob
> rfsanterre@iquest.net
>
> //////////////////////////////////////////////////////////////////////////////
>
> Charlie and Linda wrote:
>
> > ----------------------------Original message----------------------------
> > edwin gould wrote:
> > >
> > > ----------------------------Original message----------------------------
> > > I TRIED ACRYLIC SPRAY AFTER A BEAUTIFUL BLUE AND RED FROM MOLLYS BLANDING
> > > GLAZE; the colors disappeared. Any suggestions?
> >
> > Copper glazes change colors when coated with sealers due to the change
> > in the light refraction. Don't know how to stop that. Using sealers
> > did change all the copper colors for us and it did slow the fading of
> > the glaze.
> >
> > But....I hate to tell you the news.....After 15 years of thinking that
> > I'd found the holy grail of copper lusters, you know, the one that won't
> > fade....
> >
> > I don't know of a way to "perserve" the raku copper luster finish. I
> > chased copper matts for years and finally "won" just to loose. Once I
> > learned the tricky process of firing copper matts the next year I
> > learned that they all fade!!!!! Learned to fire Seth's Luster, Copper
> > Sand, Hawaiian Blue(and learned how to spell Hawaiian in the process),
> > Multi Colored Sand, etc.... They are all dying out. Did a bit of
> > dabbling in the "modified" copper glazes that weren't supposed to fade
> > and the few that worked died even faster.
> >
> > The bottom line is that copper matt and copper lusters are subject to
> > oxidation. Either this week, month, year, or next few years it will
> > fade. The acrylic, the sealers, they may help slow it down but it's a
> > done deal.
> >
> > I finally gave them up and moved on. It would have been easier to give
> > up coffee and beer as copper matts and lusters. It was putting food on
> > the table. We thought that we couldn't make it with out the "flash".
> > Well, we were wrong. Giving up copper matts/lusters drove us to
> > expriement with pit firing which lead to sagger firing and terra sig.
> > Now our income has increased 3x.
> >
> > (Good golly, this sounds like an AA meeting.....)
> >
> > If you are going to sell copper matts and lusters you are going to have
> > to ask yourself some hard questions.... How would you like to face that
> > costomer in two years. Are you going to feel proud of your two year old
> > work fading to gun metal gray or pea soup green or will you feel like
> > ducking and running? Hmm... There are several people that I'd not like
> > to meet.
> >
> > The really great news is there is life without these glazes. Flash
> > sells mediocre pots and great pots alike to people that like flash. (I
> > like a little flash, too.) But good pots will sell themselves without
> > the copper flash and we ended up growing and learning alot in the
> > process.
> >
> > Do what you have to do but coppers and all of us won't be here for ever.
> >
> > Ok, folks, start shooting at the messenger.
> >
> > Charlie Riggs
> >
> > PS-Hey, Tom Buck.. Jump in here and give them a different view!
--
Marcia Selsor
selsor@imt.net
http://www.imt.net/~mjbmls
http://www.imt.net/~mjbmls/spain99.html
http://www.silverhawk.com/ex99/selsor/welcome.html
Gavin Stairs on fri 26 nov 99
At 08:51 AM 24/11/99 , Robert Santerre wrote:
>----------------------------Original message----------------------------
>The automotive paint manufactures make a primer paint that prevents rusting
>(oxidation). Don't know how it works chemically, but it does work to prevent
>rusting of metal surfaces. I wonder if it would work for preventing copper
>oxidation? I'm not sure if the primer is made in a "clear" version. The one
>I've used was black. I got it at a Sherwin Williams store specializing in
>automotive paints.
>
>I know copper metal oxidation is preventable. Home builders put up copper
>flashing on homes. That flashing can retain its copper appearance (doesn't
>turn green) for years. How is this material treated?
Hi Bob,
Nowadays, if you want your copper to turn green, you have to treat
it. Copper naturally turns dull brown. Used to be that sulphur from coal
smoke pollution would do this for us. Not any more.
Gavin
I picked this up off the net by searching for copper patina:
Re: Why does copper tarnish to form patina?
Area: Chemistry
Posted By: Scott Hawkins, Metallurgist, Metallurgy, Bisalloy Steels (company)
Date: Sun Oct 5 23:19:35 1997
Area of science: Chemistry
ID: 874601217.Ch
Message:
Patina is the result of atmospheric corrosion on Copper. It is generally
green in colour when well established, but may be initially black before
becoming green. The green colouration comes from the copper oxides that
form.
Because copper appears low in the reactivity scale of metals, the formation
of patina takes an extended period of time, usually 8 - 10 years. Compare
this with a matter of hours for the formation of rust (Iron Oxide) on a
cleaned steel surface. The formation of patina also slows down further
oxidation once it is established, and this is why there are buildings
throughout Europe for example with copper sheeted roofs some hundreds of
years old.
It is now common to treat newly installed copper roofing with proprietary
treatments that actually accelerate the formation of patina, in order that
the aesthetics are improved, and the protective properties enhanced
immediately.
Susan Goldstein on sun 28 nov 99
In a message dated 11/25/1999 10:49:30 AM Eastern Standard Time,
selsor@imt.net writes:
<<
----------------------------Original message----------------------------
I have an ongoing test in my back yards that is eight years old. The
acylic LIquid polymer medium painted over the copper luster glaze did
prevent oxidization. What more can I say.? I painted it over "Reynolds
Wrap". The stripe where it was painted stayed coppery and the rest
turned green.
Marcia Selsor
in Billings, Montana
Robert Santerre wrote: >>
Where can we get the liquid polymer mediu? Does it have a specific name?
What is Reynolds Wrap?
Susan
Vince Pitelka on mon 29 nov 99
>The automotive paint manufactures make a primer paint that prevents rusting
>(oxidation). Don't know how it works chemically, but it does work to prevent
>rusting of metal surfaces. I wonder if it would work for preventing copper
>oxidation? I'm not sure if the primer is made in a "clear" version. The one
>I've used was black. I got it at a Sherwin Williams store specializing in
>automotive paints.
>I know copper metal oxidation is preventable. Home builders put up copper
>flashing on homes. That flashing can retain its copper appearance (doesn't
>turn green) for years. How is this material treated?
Bob -
Copper and brass plumbing fixtures are protected with a coat of spray
laquer. The same would work on pots, but in my mind, the critical question
is "Why would anyone want to preserve a copper finish by coating their pots
with plastic?" I have seen pots protected with laquer spray, and I find the
surface texture very un-ceramic, which seems counter-productive, unless you
are doing nonfunctional sculpture and do not care about the tactile qualities.
Best wishes -
- Vince
Vince Pitelka
Home - vpitelka@DeKalb.net
615/597-5376
Work - wpitelka@tntech.edu
615/597-6801 ext. 111, fax 615/597-6803
Appalachian Center for Crafts
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
Marcia Selsor on mon 29 nov 99
Liquitex makes this liquid acrylic medium. Probably any art supply store
would have it in matt, satin, gloss.
Reynolds wrap is a Raku copper luster glaze that contains barium. I
don't use it anymore.
Marcia
Susan Goldstein wrote:
>
> ----------------------------Original message----------------------------
> In a message dated 11/25/1999 10:49:30 AM Eastern Standard Time,
> selsor@imt.net writes:
>
> <<
> ----------------------------Original message----------------------------
> I have an ongoing test in my back yards that is eight years old. The
> acylic LIquid polymer medium painted over the copper luster glaze did
> prevent oxidization. What more can I say.? I painted it over "Reynolds
> Wrap". The stripe where it was painted stayed coppery and the rest
> turned green.
> Marcia Selsor
> in Billings, Montana
> Robert Santerre wrote: >>
>
> Where can we get the liquid polymer mediu? Does it have a specific name?
> What is Reynolds Wrap?
>
> Susan
--
Marcia Selsor
selsor@imt.net
http://www.imt.net/~mjbmls
http://www.imt.net/~mjbmls/spain99.html
http://www.silverhawk.com/ex99/selsor/welcome.html
Bruce Girrell on tue 30 nov 99
Vince Pitelka wrote:
>I have seen pots protected with laquer spray, and I find the
>surface texture very un-ceramic, which seems counter-productive, unless you
>are doing nonfunctional sculpture and do not care about the tactile
qualities.
I have found the same. I just don't like the feel of the pots after the
spray.
Two items that I haven't seen in this thread yet, so I thought I'd interject
them:
1) The real culprit here is the glaze itself. You might want to take a look
at Tom Buck's article regarding this problem:
http://www.digitalfire.com/education/glaze/buckraku.htm
2) Maybe I misread the original post, but it seemed to me as though the
poster had applied the clear finish and the colors disappeared
_immediately_. Some color is due to diffraction in a thin clear layer over
top of a darker background in a manner similar to the rainbow colors
produced by a skim of oil on a puddle of water. Applying a clear coat of
lacquer/acrylic/whatever on top of a diffracting layer would destroy the
color instantly since the thickness would be too great to act as a
diffraction medium.
Bruce "back into my hole" Girrell
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