Enamel question

[jplovell]

This seemed like the best place to ask this....

Does anyone know of enamels that are boro compatible other than the stuff from Ferro?

I'm looking for white opaque enamel like the stuff used for the graduation lines on laboratory glassware.

Thanks in advance for any help!


Joe

[S.C.Glass]

In the new Flow issue there is a woman mixing up an enamel powder and putting designs on beads. I think they were soft glass though. I lent the issue to a friend or I could look it up. The enamel was black but they probably have lot's of colors. Good luck.

[Greymatter Glass]

Have you tried thompson enamels? I know it's a higher COE than boro, but the layer is so thin, and the firing temps so low that it may work... I havent tried it yet. I've heard of a way to make boro compatible enamels tho:

Start with the finest grade powder you can get in the color you want. Mix it 100:1 with boric acid, this ratio may need to be altered depending on color, firing, phase of the moon, etc. Next pulverize it further with either a ball mill or a pair of finely polished steel plates (put some powder between them, apply pressure, and rub the 2 plates against each other with the powder trapped in the middle. Eventually you'll wind up with a finer than talc powder (take extra precautions when dealing with this fine of a material)

Mix with lavender or pine oil and apply. when it's dry (it may take several days in a cool and/or humid environment) carefully fire the piece either with a torch or in a high temp kiln. If you use a kiln look out for devitrification and phase separation. If you get the boric acid mixture just right you'll end up with a fluxed enamel that should melt at just a few degrees lower than the base glass without a major shift in COE.

I've yet to try this method, so if you give it a shot let us all know how it turned out.

-Doug

[PyroChixRock]

I tried it doug...doesn't work lol. I bet they'll come out with a boro coe set soon, people have been asking them.

[Mike_Aurelius]

I talked with Thompson about this quite awhile back, and they had absolutely *no* interest in making enamels for boro.

I think what the originator is talking about is a high temp paint that is applied after the piece is made and then fired in a kiln to fix it in place.

[jplovell]

This is the only stuff I have found that might be what I'm looking for:

http://www.ferro.com/Our+Products/Glass/Products+and+Markets/Container/Other+Applications/PR+System.htm

Mike's supposition is correct. I am looking to be able to apply and fire the enamel/paint/coating after completion of the piece. My concern with the product from the link is that the COE is not really that close and I would like to avoid micro-fractures in the finish coat.

Thanks for the input so far....

-Joe