Wasser- Is it compatible with 90 or 96??

[Morganica]

Oops, hit a nerve. I guess it was the tone of the remark. I guess I just get tired of hearing the same response from Bullseye whenever anyone names a glass by its COE. And excuse me if I find that that particular response smacks of marketing. (Don't use the other guys glass just because it is supposedly the same COE, it hasn't been tested against our glass.) And I hope Lani isn't reading this thread because I'm actually a great Bullseye lover. I use their glass almost exclusively, use it in my classes, and sell it in my store.

However if you will only use glass that has been tested with the chip test you can only use Bullseye glass without your own testing, which is pretty limiting. As for different viscosities playing against each other: if you test glass A against a clear standard, and glass B against a clear standard, the assumption is that they are compatible. That is what we do with a chip test in our studios and that is what Bullseye does. I don't see that it is reliably testing one colour against another if there are subtle other factors such as viscosity involved. Perhaps the viscosity differences that play nice with the clear won't play nice when you put glass A with glass B without the clear?

I know that Europeans use Bullseye with GNA with a 2-4 point difference in COE, but I believe that the method of layering is instrumental in keeping the stress from cracking the piece.

And I have never heard of 90 COE float - where is that coming from? All the float that I have ever seen was in and around 83.

I've had Spectrum System 96 pieces develop compatibility cracks. I've had a piece for 15 years that has Bullseye and Spectrum glass mixed together that is still intact. Its a fuzzy science.

I think people should be content to trust the manufacturers specifications and feel free to use glasses with the same COE without fear. If you occasionally get a crack, well that's just the nature of the medium.

In this particular case the "manufacturers specifications" say there's more to compatibility than just COE, so your statement contradicts itself. And I'm not quite sure why you equate "marketing" with "lying." Marketing is not (usually) an evil plot to hoodwink customers. In fact, educating customers is generally considered more a effective marketing strategy than lying to them, as you seem to imply that this particular manufacturer is doing.

Have you ever asked yourself why some of this "fuzzy" stuff happens? WHY can "Europeans" layer BE with GNA to keep "the stress from cracking the piece?" If your Spectrum 96 develops "compatibility cracks" despite having the same COE...why? If BE and Spectrum 96 combine successfully in a piece, despite COEs that would suggest otherwise, why? Logically, if these things are possible then there's something besides just COE at work. And, equally logically, if those factors can make glass work together, they may also prevent glasses from combining successfully.

Glass is an important substance, studied extensively, and there is a great deal of readily available information out there that can solve these puzzles. The manufacturers are one source, the Web is another, and places like Rakow bend over backwards to provide information (I just got 75 pages of information on potential devit issues in casting tonight from Rakow, in fact).

I think we can do better than a virtual shrug and "well that's just the nature of the medium."

[Lani McGregor]

Apologies for the length of this post.

Lynn,

Yes, I have been watching this thread. And I’ve been trying to keep out of it. But here I come.

I think my point was that the science of glass fusing isn't exact…

The science IS exact. If it weren’t, it wouldn’t be called science. It is the practice that is not exact…

The fact that two glasses known to be incompatible (by today’s commonly accepted standards) have not broken apart after 15 years is not proof that the science is “fuzzy”. It merely indicates that certain configurations (the lay-up, size etc) will not generate as much stress as others.

It is this - the degree of stress at the interface of the two glasses, not the COE, that ALL manufacturers test for

That stress is measurable. That is what factory testing is about. Each factory – whether they publish the information or not – has determined a level of stress that they consider acceptable between their “tested compatible” glasses and their standard.

Does anyone know how Uroboros and Spectrum test their glass?

It would be immensely helpful if UB & Spectrum would publish that information and dispel the endless misunderstanding that they are testing for the COE.

I'd be curious to know if Spectrum (they are a big company, they could probably afford it) actually tests the COE, or if they do a chip test like Bullseye, or do they rely on a calculated COE. I've never run across that information.

Nor have I. But our people have been in their factory – as they have been in ours.

Spectrum got sued for saying that their glass was a "long glass" as opposed to Bullseye's "short glass". This was technically true,..

Lynn, this was hardly a technicality. Where are you getting this information? (Incidentally there is no such thing as a “wider softening point”. A point is not a range). What is your proof? Ours is here:

http://www.bullseyeglass.com/education/ ... /tech.html

Please don’t take any of the above as an attack on you or your skepticism. I thoroughly appreciate it. I am a cynic myself and honestly revel in the cynicism of others.

None of us grows if not challenged. And the attacks on Bullseye’s credibility and integrity that occasionally surface in the face of what we think is pretty simple straightforward science are also instructive to us.

I ranted for months in my blog on the subject of the COE earlier this year, so I won’t rehash it further in this post – it clearly is a sore point for you.

For anyone who hasn’t yet been dragged through my endless attitude on the subject of COE v compatibility, here’s your chance.

Start here:

http://www.bullseyeglass.com/weblog/200 ... f-the-fun/

Then try:

http://www.bullseyeglass.com/weblog/200 ... un-part-2/

Step over the dying cat in the opening paragraph of this one:

http://www.bullseyeglass.com/weblog/200 ... un-part-3/

And the tormented surviving cat in this one:

http://www.bullseyeglass.com/weblog/200 ... un-part-4/

Lynn, this one is for you – although it obviously didn’t work:

http://www.bullseyeglass.com/weblog/200 ... un-part-5/

Finally, this one speaks directly to the difference between calling something “90” and actually matching standards between factories (again, please overlook the dead cat):

http://www.bullseyeglass.com/weblog/2007/05/12/bad-cat/

Beyond finally…it seems to me instructive to have this conversation happening on this thread at the same time that the “Need help with crack” thread is progressing at:

http://www.warmglass.com/phpBB/viewtopi ... =2&t=27369

…especially in light of the issues with cad/sel yellows and Ruth Bass’s report that her chip tests on glasses labeled with the same COE’s showed incompatibility.

Or this thread about Sue’s bowl:

http://www.warmglass.com/phpBB/viewtopi ... =3&t=27394

Once more: It’s NOT about COE. It’s about TESTING for the fit
between glasses – and that fit is a combination of more than one factor.

Oh yeah. Wasser.

When they first entered the market – a skillion years ago – they stated simply that their glass was compatible with Bullseye. To my recollection, they didn’t claim a COE affiliation. That was something that, I think, the resellers added to the promotion…at the same time that they and other players in the marketplace started to redefine compatibility.

Lynn, sorry to have made a book out of this, but I do sincerely respect your experience in the field and I regret your opinion of Bullseye’s position. We’re clearly missing the mark if we’ve antagonized you with what we honestly believe are simple statements of glass fact.

- Lani

[rosanna gusler]

thank you lani. rosanna

[Morganica]

Lynne, I built up a big point-by-point rebuttal thing yesterday and erased it; it's pretty obvious that if there are two schools of glassists, you're in one and I'm in the other, and I'm not sure there's much point in debating. Fact rarely wins out over belief or superstition or whatever you want to call it. For the work I do, it's necessary to understand at least some of the variables involved in glass science (and it most certainly is a science and not a fuzzy one) so that I can make them work for, not against, me. For the work you do--and I've not seen your work--it may not be necessary, and that's fine. I do thank you--some of your statements in other posts resparked an investigation into devitrification causes that I dropped a long time ago. Thanks to that, I've discovered some juicy things that I'm anxious to try out. So it's been a worthwhile discussion.

[Mark Hall]

I'm fortunate to have actual tons of Wasser glass sent to me around 1993 when the company changed hands. I've found it to be extremely touchy mixing with other brands of glass. I've made roll-ups and brought it to the glory hole hoping to find another way to use it up. It's got a lot of flux in it, and flows like crazy at lower temps. a lot than any other glass, which has to effect compatibility. An area supplier sells 90 compatible Chinese glass which seems to work the best - if you don't mind all the scratches, seeds, and bubbles.

[Nina Falk]

poor cat.