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Working with COPPRclay


#1

I sure hope I’m posting this right. In any case, here is my
question:

I see lots of online and in books about PMC, Art Clay
Silver, and even BRONZclay – but very, very little on COPPRclay. I
realize it’s new, but aside from Hadar Jacobson (a most generous and
talented artist, but I can’t afford her workshops), there is little
posted by anyone using this clay.

Having tried PMC and now BRONZclay, I am about to jump into the
copper stuff, but wonder if it’s to be treated exactly like the
bronze, or are there differences? I want to know (without having to
buy books plus postage until I find another job) if when I work with
the two metals in one piece, do I use copper clay paste, or bronze
clay paste? Are the firing schedules identical between the two?

I know I’m asking a lot, to get without buying another
book or another class, but it’s difficult right now. I’m mostly
teaching myself to make jewelry to keep myself from going crazy (not
to mention that I love it).

Thanks,
Cheryl Cohen


#2

Here’s my experience with copprclay, it is really really difficult to
fire properly. I have had some successful tries and several really
disappointing firings. I have followed the instructions to the
letter, calling Rio for updates and firing to the new specifications,
and my call on it is this, it should not have been offered to the
public until further work on the product to perfect the firing
schedule. I have had Rio send me new replacement product, and yet, my
recent firings were not successful. I am not sure that the batches of
the product are consistent, and for sure the results are not. The
other consideration is the carbon in which it is fired, which
eventually wears out. But…there is no exact science as to how long
the carbon is good, nor does anyone tell you how to tell if that is
the problem. I think, the company was too quick to release this
product without learning how to manipulate it properly for
consistent, successful results.


#3
but wonder if it's to be treated exactly like the bronze, or are
there differences? I want to know (without having to buy books plus
postage until I find another job) if when I work with the two
metals in one piece, do I use copper clay paste, or bronze clay
paste? Are the firing schedules identical between the two? 

The Coppr works pretty much like the Bronz. Use copper paste of
course. Firing schedules are different, copper fires higher.

Pam East gave an excellent presentation at the Metal Clay World
Conference on enameling on CopprClay, you can read her slideshow
online through Art Clay World.

Her firing schedule is for enameling, you don’t have to use it if
you don’t plan to enamel.

You can also get a lot more by joining the yahoo group
Metal Clay Gallery.

Elaine
http://www.CreativeTextureTools.com


#4

The copper and bronze “clay” systems are really pretty simple. They
use a standard powdered metal product that is made for making
sintered metal products.

The metal powder is coated with a very simple layer of a lithium
stearate soap powder.

This powder is added to keep the dry powder fluid and not clumping
during the standard process of making powdered metal parts.

The process has been in use since the 1920’s.

The “new” process for hand molding adds water to the powder to make
the particles stick together by moistening the soap.

A first stage of sintering requires that the soap be burned off.
This requires oxygen pretty much at about 500 F. incomplete burning
makes a mess.

Industrially this is done in a section of a belt furnace in air or
moist air and only takes a few minutes.

The next industrial stage, is sintering the now clean metal powder
at a higher temperature in a reducing atmosphere containing
hydrogen. In the art metal clay process This is “attempted” oxygen
free without hydrogen for safety reasons. It doesn’t work that well
particularly with copper.

The use of a carbon filled box can reduce the oxygen content BUT a
reducing atmosphere then requires CO - carbon monoxide to be
present. this requires enough oxygen to make CO.

It is a self defeating system - particularly with copper.
industrially sintering takes place in only a few minutes in the
oxygen free, hydrogen containing atmosphere.

This won’t work very well or really at all in the ART process as you
have found.

Fooling with time at temperature won’t improve things at all as you
are finding out. A good result is more accidental than intentional.
The application has not been thought through properly. The tin bronze
systems are a little better.

jesse


#5

The firing schedule for COPPRclay is different than BRONZclay.
Copper has a higher sintering temperature than Bronze. Because I have
enameling issues to deal with, I use a two phase firing schedule. It
might be overkill for projects that are not going to be enameled, but
it certainly won’t harm anything.

Phase 1: Fire on an open shelf (no carbon). If the piece has any
curve or doming, support it with fiber blanket. Use a ramp speed of
500. Fire at 560 for 15 minutes. This will burn out the binders. The
piece will come out black and brittle.

Phase 2: Bury in activated carbon. Full ramp to 1750 degrees for 3.5
hours. Let cool in the kiln.

I personally have found this schedule gives me the most consistent
sintering for COPPRclay. I am able to dap and bend the pieces after
firing.

Enjoy!

Pam East
www.pameast.net


#6

Hi Cheryl,

Although Orchid is made up of a great group of people who make metal
objets, it is not a group that deals specifically, if at all, with
metal clays. Go to the Yahoo metal clay group (just google it). There
is a great deal of on copper clay, bronze clay and silver
clays in the archives and then go to Metal Clay Academy (again google
it). Margaret Schindel has put together, on that site, very thorough
info on all the metal clays.

Hope this helps,
Linda Kaye-Moses


#7

If you haven’t already done so, be sure to check out the metal clay
yahoo group:

http://groups.yahoo.com/group/MetalClay/

This is probably your best source for finding out what experience
others have been having with copper clay.

The Hadar Jacobson has posted on her blog
(www.artinsilver.com) is the best and only published info on
combining bronze and copper clays. There may be a few posts on the
metal clay group archives on this.

Knowing your kiln and its idiosyncrasies is essential. Temperature
can be very important when firing these types of clays, so if your
kiln has hot and cold spots or the thermocouple is not registering
correctly, you will have problems that you need to work out. To a
certain extent, extending firing times will help if your
temperatures are a little too low.

As far as using slip to attach the two metals, it should not matter
which you use as you are combining them. Just be sure to score and
use a thick slip and pressure to make joins. The two metals may
shrink at different rates, so you should do some experiments to see
what types of joins work best for you. This is essential to do before
you begin designing your pieces. Do review Hadar Jacobson’s posts on
combining the various types of metal clays as they will give you an
excellent starting point.

Alas, if you are not willing to spend $$$ on a workshop, you will
have to spend time, materials, and energy to do your own
experimentation. You could also wait for Hadar’s new book to come
out. It is scheduled to be available in October.

For those who are unwilling to allow for time and materials in
experimentation, I would suggest sticking with the silver clays that
are well documented. Despite the higher material cost, you may end up
spending less because there will be less waste in time and materials.
Buying base metal clays may be a false economy in many cases.

Cheers,
Mary Ellin
Mary Ellin D’Agostino, PhD
www.medacreations.com
Sr. Teacher, PMC Connection
Certified Artisan, PMC Guild


#8
The use of a carbon filled box can reduce the oxygen content BUT a
reducing atmosphere then requires CO - carbon monoxide to be
present. this requires enough oxygen to make CO. It is a self
defeating system - particularly with copper. industrially sintering
takes place in only a few minutes in the oxygen free, hydrogen
containing atmosphere. 

Sorry to disagree here Jesse but this works quite well to provide a
reducing atmosphere. There is plenty of oxygen diffusing into the
heated charcoal to create a CO atmosphere in the box. I have been
using this technique for many years to bond mokume. If you do not
allow the box/charcoal to sit at temperatures of less than 1400 F it
will be a strongly reducing atmosphere in the charcoal. But it must
be that hot for the reaction between the charcoal and oxygen to be
rapid enough to produce significant amounts of CO. This process was
once used to create reducing atmospheres in heat treating furnaces by
passing air through a heated beds of charcoal and then into the
furnace.

James Binnion
James Binnion Metal Arts


#9
Metal Clay Academy (again google it). Margaret Schindel has put
together, on that site, very thorough info on all the metal clays. 

The poster was mixing up two different sites. Find Margaret’s
site(s) at:

Elaine
http://www.CreativeTextureTools.com


#10

First, I’d like to thank everyone who has responded here and
privately to my quest for COPPRclay info.

I’d just like to say that it is not that I am *“unwilling” *to pay
for more workshops and books right now; it’s just impossible. I
already have the clay, so I am going to dive in and cross all
appendages and hope for the best. Again, I have read extensively on
some of the other sites, but aside from Hadar’s, have come up short
on much COPPRclay info. I will be eager to check out the rest that
you’ve suggested

Metal clay is not the only thing I’m trying, so I hope you all don’t
mind if newbies like myself continue lurking here and absorbing all
the knowledge we can get. Even though (allegedly) the thrust of
Ganoksin is not metal clay, there seem to be many people here who
have tried it, and have been kind enough to respond. Although the
presence of established artists can be intimidating, I joined this
site because it appeared to me that neophytes are welcome. We all
have to start somewhere, right?

All of you are greatly appreciated.
Cheryl


#11
This won't work very well or really at all in the ART process as
you have found. Fooling with time at temperature won't improve
things at all as you are finding out. A good result is more
accidental than intentional. 

Well, while I will endorse the idea that these processes have not
been fully worked out for the art products, I cannot agree with the
above in regard to copper clay in particular.

First, the composition of commercial copper clay is different from
the industrial process, being based on methyl cellulose, not soap.
Your description of the process looks sound to me, just the same.

I have done many firings of bronze clay and several of copper. I
agree that bronze is more accidental than intentional, though some
people seem to have success with it. I’ve put it aside until it is
better worked out.

Copper, however, has worked for me every time, if it is fired in a
2-stage process such as you describe. It is heated to about 500F for
15 minutes on an open shelf, cooled, buried in carbon and fired to as
high as 1650, held for 3 1/2 hours. I’m not sure how the length of
time was established, but it does take time for the box and carbon to
heat thoroughly.

I do not use this product extensively-- my interest in it is largely
because my students are interested, though I have visions of more
sculptural, larger work. I wanted to do those in bronze, but as I
say, I have set that aside for now.

Still, it IS possible to get some wonderful results with these
materials. Once again, I refer interested people to Hadar Jacobson’s
site, and her blog in particular.

Noel


#12

I am well aware of the wide spread use of CO for the reduction of
metals since the beginning of metallurgy. On a small scale it has
problems including safety in poorly ventilated spaces. The CO
combines with the hemoglobin in the blood as does oxygen - BUT the
blood does not regenerate - the oxygen capacity of the blood is
reduced. This is cumulative a little today, a little tomorrow and
some more the next day can really hurt or kill you. It will have a
quicker bad effect on children.

Eventually the bad red blood cells are replaced in the normal course
CO is not usually detected by smell, but too much exposure will give
you a metallic taste in the mouth.

This is a bad sign-- quit at any sign of this, and keep away from it
for several days. Pure oxygen can help but it doesn’t regenerate the
blood cells It just like a charcoal grill - don’t do this the house.
It is dangerous in very small concentrations.

The charcoal doesn’t wear out it is consummed to ash just like in
the grill

jesse


#13

Jesse,

I am well aware of the wide spread use of CO for the reduction of
metals since the beginning of metallurgy. On a small scale it has
problems including safety in poorly ventilated spaces. 

I figured you were aware of the past industrial uses of CO in heat
treatment etc but added it as info for others. As to the dangers of
CO you are absolutely correct, it is yet another reason for proper
ventilation in the studio.

Regards,
Jim

James Binnion
James Binnion Metal Arts


#14

You are missing the tell tail sign of the lithium stearate! The moist
material is more fluid (flexible) cold than warm. This is a very
unusual counterintuitive material property. The lithium will add this
property…

He may have added some other stuff. Before I discovered the lithium
effect I thought about what additives would help… ??? I didn’t come
up with anything to really try that would add this counterintuitive
property as well as being clean to remove.

Hardar is one smart lady! she worked this out herself.
jesse


#15
I agree that bronze is more accidental than intentional, though
some people seem to have success with it. I've put it aside until
it is better worked out. 

Huh. That has not been my experience with the Metal Adventures (Rio)
BronzClay. With the two phase firing schedule (no open shelf) I am
getting really good consistent results.

The keys are – don’t overload the box. If you put much less in the
box than you would like to, that improves your results by a lot.

And I switched to a smaller box.

Elaine
http://www.CreativeTextureTools.com