Can you use 104 enamels to torch fire on copper?
 

Anyone know if 104 enamels will work alright torch fired onto copper?

Lisa I am no expert on enamels, but took an enameling (on copper/silver) workshop this fall and from what I know - the answer is no. I was curious about this as well, since I use Thompson enamels in my glass work.

Rats. That's a bummer. I may have some left from making copper enamel beads years ago but it's chunky mostly like really big frit. My 104 is perfectly powdery.

There is a book by Barbara Lewis on firing enamels onto metals for beads and such, but the book does indicate that the enamels are by Thompson specifically for copper, silver and gold and other metals. The book has lots of information, great ideas and inspiration.

http://www.amazon.com/Torch-Fired-En.../dp/1440308861

Also, on Etsy there are many sellers with torch-fired enamelled beads, just for browsing.

I'm thinking that the 104 enamels would not work, but someone else might have more insight. Someone is bound to have already tried it and would have the correct answer for you.

Yvonne

Call Thompsons and ask.

Technically no, but I have done it, with the purples and orchids, and it has worked. Not sure where the piece is now, but last time I looked the finish was fine and the piece was 2+ years old at that point.

Probably fine for practicing til you can get the proper ones.

Can you put copper in beads with enamel?

If so.. I don't see why not. Maybe?

well about 1 year ago I used my thompson 104 enamels for glass on a flower copper shape that I cut out. I used two different shades of green. it is on my desk, gets pushed around, mixed with my give away beads dish, kids pick it up and try to play with it..LOL Its still just as good looking as when I did it. I never tried any others but I figured I'd share my 2 cents just incase anyone was curious.
sue

Thanks for the info everyone. I appreciate the input

Ms. Lewis uses murrini as inclusions in some of her pieces so I am thinking that 104 is probably okay. I think the problem is in using anything but 104 enamels on lampwork.

The enamels used for copper, silver and other metals is different than the 104 Thompson enamels for glass. They are a different COE. You can use a bit of it on metal but covering a whole piece of metal with glass enamels will surely cause cracking. Some colors are more sensitive to issues than others.

Do you know what COE metal is?

I just called Joan at Schlaiffer's Enamels. She is out of town until the 6th so I will report back here when I hear from her. Hopefully she will provide some clarification on this subject.

from the table in this link

http://en.wikipedia.org/wiki/Thermal_expansion

it looks like copper has a COE of 170 (in the same units as we use for 104, 96, 33, etc)

So the closest glass in COE terms might be the very soft Jappanese glasses?

I've also read that copper is around 170 COE and even then I think there might be some issues with the shape of copper that changes the COE. I've had issues enameling round copper wire. The enamel keeps sharding off. But if I pound the wire flat and enamel it, it's good.

from this site:

http://www.porcelainenamel.com/pei502.htm

enamal COE's range from 80 to 140 depending on composition. Enamel is stronger in compression, so if there is a COE mismatch, it's better if the enamel has a lower COE than the metal. Maybe that's why some people have had success with 104 COE enamel on 170 COE copper?

Anyone try it on silver?

I talked to a technician at Thompson and the COE for the enamels used on metal is 86-120 depending on the color. I think it is more that you shouldn't use enamels for metal on glass than the other way around.

Thanks for checking Julie. Think I am going to try it and will let you know the outcome.

Does anyone know if copper wire can be placed directly on a bead ( no enamel ) the same as using silver wire?