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Is there a list somewhere that shows what the C.O.E. for most of the Glass Mfgrs glass is, i.e. Armstrong, Youghiogeny, Wissmach, etc. I know most Bullseye and Uroboros is 90, and most Spectrum is 96. Just wondering if I could fuse some dichroic into glass by these other mfgrs without having the trial and error of testing first.

J. Savina wrote:Is there a list somewhere that shows what the C.O.E. for most of the Glass Mfgrs glass is, i.e. Armstrong, Youghiogeny, Wissmach, etc. I know most Bullseye and Uroboros is 90, and most Spectrum is 96. Just wondering if I could fuse some dichroic into glass by these other mfgrs without having the trial and error of testing first.

Glasses that are not manufactured and sold as "tested compatible" can be all over the map. They don't really care unless 2 colors are included in a sheet.

I once tried slumping a sheet of Youghiogeny and it came apart. The colors weren't even stuck together.

BTW Uroboros makes both 90 and 96 and Spectrum sells only 90.

Unless you love devitrification and broken glass stick with glasses that are intended for fusing. There are a few exceptions, but most likely you don't need to know about them.

For that matter, unless your organizing skills are better than most, I'd stick with one system and you won't mix them up.

In the case of Armstrong, the glass used to made in the US, but is now often made in China. The COE could be almost anything.

In the case of Youghiogeny, people report that they generally don't have good luck fusing it. It either devitrifies, turns muddy, or causes other problems and some say the sheets aren't even compatible with themselves.

In the case of Wissmach, they do make one glass for Bullseye, so there may be some varieties that work for you. But many won't -- people have reported some devit with Wissmach.

In the case of etc., the short answer is that you shouldn't fuse dichroic (or any other glass) onto any glass by any other manufacturer without first doing testing. And that's true even if you know that the glass from a manufacturer tends to be around a certain COE. Unless the glass has been tested compatible by the manufacturer, you have to do compatibility testing on your own or risk ruining the piece (not to mention wasting some very expensive dichroic).

Also, if you go to the Old Archive (click on link at top right of page), and search on various glass names, you'll find some info on glass by most manufacturers.

Thank you very much for all your input. I've never tried to fuse with Yough. I've only fused with float glass/murini slices- 104, Spectrum/Uroboros 96 and Bullseye/Uroboros 90. I was hoping that some Armstrong or Wissmach glass might be compatable with any of these. Oh Well, I guess I'll just have to test it and maybe somewhere down the line, get a stress meter. Thanks again. J.

Bert Weiss wrote: I once tried slumping a sheet of Youghiogeny and it came apart. The colors weren't even stuck together.

That's too bad. I have some scrap Youghiogheny that is stunning (well, of course.) It'd make a great single layer...something. I kind of wondered if it'd turn to mud or worse.

Now here's a dumb question...if that sheet was so incompatible that it fell apart during a slump, how come it doesn't fall apart during the manufacturing process? Or - worse yet - after a few years in a window?

- Bev

Bev Brandt wrote:

Bert Weiss wrote: I once tried slumping a sheet of Youghiogeny and it came apart. The colors weren't even stuck together.

That's too bad. I have some scrap Youghiogheny that is stunning (well, of course.) It'd make a great single layer...something. I kind of wondered if it'd turn to mud or worse.

Now here's a dumb question...if that sheet was so incompatible that it fell apart during a slump, how come it doesn't fall apart during the manufacturing process? Or - worse yet - after a few years in a window?

- Bev

Bev

What I think happened was that the 2 colors being mixed in to the sheet chilled on the rolling machine before they fused with each other. I guess it must have been close because it did form a sheet. I was as disappointed as you can imagine because it was a handsome piece of glass. It belonged to a client so when it didn't work, I didn't get a job.

Of course, you really have to test, but I have found lots of Kokomo that tested compatible with Spectrum, mostly transparents but a few opals. It has the same devit issues that the regular Spectrum has, but you can always cap it with System 96 clear for good results.

I have slumped with youg. glass in a single sheet into a bulleye mold it has come out good the colors have changed and muddied a bit but for a candle holder it is ok.

I have contacted both Armstrong and Youghiogeny about their COE's.

This is what Youghiogeny wrote-

'The COE is close to 90 but can vary from sheet to sheet.
The top of the sheet may have a different COE from the bottom.'

Armstrong quoted me a COE of 'about' 90 as well.

I would test before using either but they both work great for beads

Oh and Kokomo said 'about 92'

quill wrote:I have contacted both Armstrong and Youghiogeny about their COE's.


Oh and Kokomo said 'about 92'

Well, that's interesting cause I have found quite a few that tested with the System 96.

Well Lynne, they wouldn't warrant their glass COE for fusing but this was answer I got. I checked my e-mails to make sure before I posted that. They were pretty fast about answering emails if you want to check with them.

I don't think that their specs on the glass are reliable, anyway. Its not intended for fusing. I might just try some Kokomo with the GNA, though if they say its 92, or even with the Bullseye. I just thought that since the ones I tested worked with Spectrum that they would all be too far off to work with the lower expansion glasses.

I guess the lesson here is if you find a glass you really want to use, test it against every known clear you have.

I might just try some Kokomo with the GNA, though if they say its 92, or even with the Bullseye.

I have used the Kokomo with Bullseye stringers in beads & had no problems with compatibility... but I agree, testing is the only way to tell what you can get away with.

BTW Uroboros makes both 90 and 96 and Spectrum sells only 90.

I think you might have meant 'Spectrum sell only 96'

Coe's are not always the direct indication that something will work or not work. Dan, from Bullseye gave several lectures at past GAS conferences concerning this. Fluidity can have a big effect on what fits and what doesn't just as firing, temperatures reached and shapes of particular pieces. I know that Bob Banford, a well respected lampworker once told me he could use glass ranging from 88 to 104 COE in the same paperweight and not have a problem. Note: he has many of his pieces in many notable museums. It is possible to even have glass change coe on you when you are working the piece. People have indicated that some reds can change as much as 6-8 points when working it for blowing a piece. If it is reheated too many times all kinds of different chemical reactions can take place. I have pieces I made over 25 years ago that should have fallen apart in the first 10 minutes they came out of the annealer and they are still holding together. There are no absolutes, just some things that will work a greater percentage of the time than others, unless you've got a phenomenal chemist working for you. Trust me there's always a chance that you can do the same thing every day for 30 years and then one day it won't work as it should. that's the beauty of working with glass. don't think you've ever got it mastered. just as you think it's mastered it will bite you in the ___.

Fuhrman Glass Studios Inc wrote:Coe's are not always the direct indication that something will work or not work. .

I'm glad that someone besides Bullseye is finally beating this dead horse.

The COE is NOT a reliable indicator of compatibility.

Anyone want to hazard a guess as to why newbies keep thinking it is?

-Lani

Lani: most newbies haven't grown up with the trials and errors that some of us oldtimers have had to contend with. They are of the computer-age. Take it home, unpack it and it does all the work. There is no room for any thing to not be right , or it's returned or otherwise they'll sue whoever made it. Time teaches a lot of things and until people actually have to try and create their own glass from scratch and color it, they have no inkling of what's involved. people think you just pour in a little cadmium and you automatically get some beautiful yellow, or red, or orange or who knows what if you are off in your measurements and firing temps. Without all the work that a few manufacturers have done the warm glass vocation would still be a "fly-speck" on the glass scene. They deserve a big thank you! Thanks! Tenn. Tom