Red vitreous enamel on copper

Red is a tough color to fire direct on copper because of the
love/hate relationship with the oxides formed during firing.

Does anyone out there in Orchid Land know of a transparent red that
has a high success rate on copper?

I know that the best color is achieved over flux but that is not an
option. The enamel thickness is restricted and the flux would be
exposed during the grinding steps. Also, I must work with the
existing copper base, I do not have the option to change metals.

I recently tried Schaurer transparent rubys but was very
disappointed with the white grainy contaminants left in the fired
surface [brand new purchased enamel, 5 different reds, same
results]. Is there another brand that I can count on???

I’ve also tried the Thompson non-leaded reds but their firing times
are so long that I risk burnout of other colors used on the pieces.

Hoping someone has the answer I’ve been pursuing for 4 years.

Karla Maxwell…in not so sunny S. California

Is gold enameling foil too thick for use there? Small amount will
really help with the reds

You might want to try the 103E red (Ninomiya or Aoki) available from
Enamel work Supply in Seattle. She sells small samples, so it may be
worth a try. I work primarily on fine silver – but this has been
the best behaved red I have ever worked with (beautifully
transparent with no specks) – so maybe it will cooperate with
copper. This enamel was designed to fire directly on silver without
an undercoat and not turn that ugly orangey-brown color. There is
also 105-A & 105-B which are both beautiful colors, but I also got
some of the white specks you mentioned with the 105-A.

Also, regarding the specks/contaminants you got in your Schauer reds.
I purchased 5 colors of the Schauer enamels through Rio (I was so
excited when they started carrying them.) But alas – they all had
strange whitish specks in them after firing. I contacted the sales
director through Milton Bridge (where I used to buy Schauer enamel in
bulk – and never had any problems with the enamel.) He said that
occasionally refractory material from the manufacturing and grinding
process of the enamel would contaminate a batch – but was something
they seriously tried to prevent in their quality control. But ALL of
the Schauer enamels I bought from Rio Grande had this problem… it
was the worst in the red/brown and violet purple. I sent them back,
and actually had them send me a couple of other samples from other
lot numbers and still had the same problem. Thankfully Rio Grande has
amazing customer service, and took the returned enamels and credited
my account, but I was sooooo disappointed, because Schauer enamel is
known for it’s quality. I have purchased them before and not had the
problem with the white specks, but am now reluctant to purchase
Schauer enamels again from Rio in case this is an ongoing recurring
problem. Has anyone else experienced this … what is going on!!!
Big Bummer!!

Well, give the Japanese red enamels a try – best of luck. P.S.
Seeing your post reminds me that I need to send in my Enamel Guild
West dues – eeeek!!

Kelly Luttrell Payne
www.indigoflameworks.com

Karla,

What are the other colores involved? Is this a repair? For very good
transparency washing is usually necessary. Although reds over copper
with no flux tend to be very dark. Perhaps silver foil if there is
something to fire it to.

Feel free to call or contact offline. More info facilatates more
accurate answers. later, Mark

Mark Thomas Ruby
SunSpirit Designs

I just took Linda Darty’s workshop. In it, she taught how to achieve
the most beautiful reds by manipulating clear flux and working with
the oxides present in the copper.

Thank you once again, Linda, it was fabulous.

If your color is transparent, the color of the copper, will always
show through the layers and therefore if you are using red, the
color will not end up red.

Can you plate the electaformed piece in fine silver and then use
japaneese enamels, first flux, then red for silver?

Maybe use underglaze cayons. Color the the electraformed pieces and
then put a top coat of flux.

Jerell Skirboll

Thank you to those that offered suggestions and also contacted me
off line.

The suggestion of gold foil under the red is a traditional method if
thickness is not a problem. Taking that further, I previously tried
a 24K gold plate direct on copper to act as the base for the enamel.
Unfortunately it did not work. I believe because the copper is so
reactive to other metals that the gold migrated [alloyed] during the
firing process. The gold was as thick as logically possible.

So, I’m still in a quandary. The best to date is the Schaurer but
I’m frustrated with the @%#*%^ contaminants that slow down the work
and impede the quality of the transparency.

Still hoping…Still searching
Karla in Sunny So. California

Taking that further, I previously tried a 24K gold plate direct on
copper to act as the base for the enamel. Unfortunately it did not
work. I believe because the copper is so reactive to other metals
that the gold migrated [alloyed] during the firing process. The gold
was as thick as logically possible. 

Gold and copper are virtually the same size on the atomic scale.
They easily substitute for each other in the crystal matrix so they
easily diffuse into each other even at room temperature. When plating
gold over copper if you want the gold to not sink into the copper you
need a nickel barrier layer to be plated between them. I must say I
dont know if that would allow the gold plate to work for enameling
but I have significant doubts that even the nickel barrier would
allow this to work.

Jim

James Binnion
@James_Binnion
James Binnion Metal Arts

360-756-6550

Dear Kelly,

But ALL of the Schauer enamels I bought from Rio Grande had this
problem... it was the worst in the red/brown and violet purple. I
sent them back, and actually had them send me a couple of other
samples from other lot numbers and still had the same problem. 

We are pulling the Schaure packaged stock enamels and comparing it
to stock prior to packing to see if there is anything on our end that
can be causing this problem. We will continue to do our best to
isolate the issue and correct it, so hopefully this will be rectified
ASAP.

Thanks for the kind words and our sincerest apologies you have had a
negative experience.

Sincerely,

Thackeray Taylor
Rio Grande Technical Support
505-839-3000 ex13903
800-545-6566
technical@tbg.riogrande.com

If your color is transparent, the color of the copper, will always
show through the layers and therefore if you are using red, the
color will not end up red. 

I’ve only played with enamels a bit - no expert. A different tack,
though: Have you considered bypassing all the grief and just
using.999 silver when you need red?