Boro Enamel. 33 COE enamel.

[AdamCotter]

Any chemistry people on here? How would one go about formulating glass that would still have a coe of 33 but would melt at a slightly lower temp? Increase the Borax? Ive been experimenting with grinding fine powder from colors and adding a bit of gum arabic, soap, and gylcerine, this combo (in minute amounts) seems to burn off cleanly, but the enamel melts at the same temp as the piece, so it works with a torch, but i want Thompson style enamel that will work in the kiln.

WHAT I REALLY want is MacroCristaline glaze that will work with Boro glass. That shit (if you aren't familiar) is SICK!!!!

http://ceramicartsdaily.org/wp-content/uploads//2010/10/crystalline_3.jpg

It won't work tho because the crystals form at about 2300 degrees over several hours. The same basic concept as our Striking colors.


how do i make pics show up here?

[AdamCotter]

Is this thread in the right place?

[AdamCotter]

http://ceramicartsdaily.org/wp-content/uploads//2010/10/crystalline_3.jpg

[Firekist]

my wife has a vase with that on it.. every time i look at it, i wish i could make it happen in/on glass as well! the pictures don't show the detail that's really there.. way cooler.

i've wondered the same.. but this kind of chemistry wasn't close to being taught in undergrad chem courses.. so i have no idea =(

gluck!
---seth

[menty666]

I'm not sure they can, really. Thompson (the folks who make the 104 compatible enamels) have been trying for quite some time now and still haven't gotten a 33 compatible enamel.

I'd like to hope someone out there can crack it, but so far, no dice.

The closest we have is the powders.

edit: You might try experimenting with graal or sgraffito techniques to get a similar effect. I've seen some awesome stuff recently that makes the glass look like the old style whiskey jugs.

[Aymie]

Mz once told me how to do this. You have to get a powder that is even finer grit than what us normally sold. Then it can be mixed with some sort of oil and used as enamel.

Not sure how to get the crazy crystal growing effect though.

[Kevin Bumble]

Interesting...

[gambitglass]

I had crystals grow on the walls of a boro tube once and I had no idea why it happened. I must have had something on my hands that I did not clean off well and it caused snowflakes to grow on the glass when it was slowly heated? Wish I could be more help, I may even have the glass still in the shop, if I find it Ill post a pic.

[Julian]

GA makes a very fine powder, finer than NS (or do they not make this any longer?). However, soft glass enamels are highly saturated, and so the pigment very intense - many enamelly style techniques wont work with lousy wispy boro black powder.

[Riley]

i'v been asking about this here for years. definitely a whole world effects yet to be utilized. having your own logos etc made for your art is one thing, but actually hand applying by brush or dipping would really be a whole new realm.


i was told pebeo enamels might work. it seems like all the companies that make enamels are fairly large corporations that supply directly to companies that silkscreen logos, and scientific glass labels. there doesn't seem to be anyone producing or marketing a product for artists, which is a shame.


stay on the hunt !

[jr23]

there was a guy down the street from me that did stained glass, killer stuff. He would cut his glass to shape then do enamel work on it. all his work was great and his faces where so real.

I never got to play with any but said some fired at close to our annealing temps.

[T-Rex]

Some glass chemistry:

SiO2, silicate dioxide (mineral name = quartz) will form a glass when melted and cooled quickly (if it's cooled quickly, it becomes the mineral quartz. devitrification = mineralization). This glass will have a very high fusing temperature, ~2200F, as we know from quartz glass.
Sodium (Na, often in the form of sodium carbonate) is added to lower the melting temperature, but this makes the glass water soluble, which is not cool.
Calcium (in the form of 'lime', calcium carbonate) is added, it interrupts the molecular structure and prevents water solubility.
That's sodium-lime glass.

Boron is added to lower the COE, creating boro-silicate. In boro-silicate there is usually only very little Ca or sometimes other elements are used, like Al (aluminum)... also you will find that occasionally potassium is used in place of the sodium.

You could try adding more sodium or potassium. There are plenty of other elements that will lower the melting temperature as well, but they usually all have some sort of side effect, and I can't remember what they are off-hand. Lead is another one actually, Pb, it lowers the working temperature, lowers the viscosity (more fluid-like), and even increases the optical purity, hence lead-crystal.

I apologize in advance for any mistakes I've made here... it's been awhile since I was in school by now haha!

[T-Rex]

One other thing I wanted to add... generally speaking, enamels are metal oxides.

There are plenty of enamels that are used in stained-glass work. I've made many stained-glass pieces fired with enamels on top. In small quantities the different COE of the enamel doesn't cause problems. You could try using stained-glass enamels on boro and see what happens. Usually the fusing temperature of these is much lower than the melting point of the glasses, however higher than the slumping point. One solution would be to apply the powders on the glass and melt the skin in with a torch (and very good ventilation). In the kiln reaching those temperatures would cause slumping.

I know it's still not quite what you're looking for, but could be worth experimenting if you find some enamels cheap!

[Julian]

You want to have something encaseable, ideally. I'd be as concerned about compatibility as firing temperature.

The pigment painting techniques used by Axel (glassmax) are probably the closest thing I've seen in boro. If you didn't catch his posts: http://www.talkglass.com/forum/showthread.php?t=40407