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Charles Willis 09-29-2019 07:54 PM

System 96 + Glasma mismatch
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I had a very interesting failure recently and I thought Iíd post the story here. Maybe it will sound familiar to somebody or maybe it will save someone some trouble. I made murrine by fusing stacks of System 96 sheets and cutting the resulting blocks into squares. The murrine were 6 mm thick and I framed them with strips of black and white. After rolling it up I covered it with one gather of Glasma.

A week after making, I did a flat grind on the bottom and put it on a shelf. Two weeks after making, it spontaneously exploded. From the other side of the house, it sounded like somebody dropped a pile of dishes.

The obvious suspect is 12 different colors of System 96 but I have had a couple of failures using Reichenbach colors with Glasma while I didnít have a single one in my previous studio using Cristalica. I realize that Iím mixing some unusual things but if anyone has any ideas, Iíd like to hear them.

Jordan Kube 09-29-2019 08:47 PM

You are mixing some unusual things.

Patrick Casanova 09-29-2019 08:48 PM

To my eye looking at your images, I'd say it is not a compatibility issue. I say that based on the fractures not appearing to have anything to do with the patterning or layering. You mention an old studio and not having problems. I'm guessing that this piece got put away a little cool and the stress from putting it away was not removed when annealing. I think the culprit is in your process somewhere. What do your polarized lenses show? My 2 cents worth.

Patrick Casanova 09-29-2019 09:36 PM

I'd suggest that next time you blow, throw the pieces in the oven, bring it up a little slower than normal and up to the higher end of your normal temperature range. Let it soak while you work and re-anneal them. So now you know annealing is not an issue. Then take some butter cut or masking material and cover some areas. (Inside surface) Then cut out stars and lightning bolts over each color. Then lightly sandblast through the color layer exposing the clear. After cleaning it up start inspecting it from the outside surface under a good light. If you have a compatibility problem you'll see hairline cracks off the points and tight valleys. It's Old School but it's how we used to test the changing cutlets against our colors before the smart kids came along.

Shawn Everette 09-30-2019 10:15 AM

What's the coe on the glasma? Been to both their sites, and through some of our archives, but not getting a result, just "designed to work with colors".

System 96, especially the plate, was never made with blowers in mind. It's also not really 96 according to the pros on here.

Pete VanderLaan 09-30-2019 11:53 AM

what the photo fails to show clearly is whether there is other color for the inside gather and that would indeed promote the mismatch.

The outside color appears to either have been worked really cold, so that much of the color stands proud on the surface or the color stands proud because of substantial mismatch on viscosity. Either way, it's mismatch. I very much doubt it's the annealing.

I know enough people who use commonly accessed GLASMA batches to not suspect it has some wild L.E.C. The Sys96 is a known 94.1. That going together with the GLASMA, which is in the 96-96.5 range more than enough to cause the break.

My opinion though. What do I know? I liked Jordan's answer.

Shawn Everette 09-30-2019 12:59 PM

I think it was a collar roll up, there's a lot of texture on the interior of that piece. He said he gathered over so there shouldn't be any exterior texture, which is evident on the first photo.

I too thought glasma was going to be closer to spruce, and we already know about spruces's problems with system "96". I was able to get away with some system and cristalica mixes.

Pete VanderLaan 09-30-2019 02:51 PM

The grinding really messes with the surface tension of the glass. Pieces that would hold together for long perids of time will break up rapidly once the grind is done.

That's true of taking Kugler opaques and working them with SP87. If you grind them they will more often than not, fail. Spruce Pine made the SP83 specifically to match the kugler opaques which all hover around an 88-89. The opaque reds and yellows are more like an 85 and since those colors do not contain any lead, they are far more sensitive to mismatch.

Cristalica is measurable at between 96.8 and 97+, making it higher than SP87. Any of these glasses that haven't broken, in my mind, haven't broken yet. I tend to think that much of the glass made since 1970 or so won't be here for all that long.

Shawn Everette 09-30-2019 04:40 PM

Don't cold work, got it.

I gave up on Kugler early on after fighting with some imperial red and oxblood. That and constant shipping errors. Any idea what Zimmerman was? I've got a really great ruby that's never been compatible.

There's a local museum with a collection from mostly the 70's and 80's; Labino, Lipofsky, Littleton, Dale, Jolley, ect... Have noticed cracks in several of the pieces. Most people wouldn't give it a second thought, but as a blower it's the first thing you see.

Pete VanderLaan 10-01-2019 08:22 AM

I still continue to wonder whether signing the bottoms of those pieces is sufficient enough to break the surface tension.

Zimmermann, as beautiful as it was, really had expansion issues far too frequently. Paul Marioni was in love with their Mother of Pearl colors which I think were phosphate opal rods, but nothing fit. That was pre SP87 days and the clear at the time at Pilchuck at least was either cullet from the bottle plant down in Seattle or it was light bulbs. Rob Adamson, Mark Graham and I used to drive down to the plant and they dumped our barrels full with a front end loader filled with still hot cullet from the plant. Then we would teeter off to Stanwood with no brakes. Later we came back and had soda ash pneumatically pumped from box cars into the same truck. The two were mixed. We used about 3,000 lbs a week. Awful stuff.

At one point I made a tank of a flawless clear using my own formulas as a 96. When Dale found out, he made me dump it on the ground being concerned I think that students might really like bubble free glass. I kind of lost interest in teaching there after that.

I too have noticed lots of cracked vintage glass.

Shawn Everette 10-01-2019 11:51 AM

Considering how weak the scratch from a cutter makes plate, it wouldn't surprise me if there was some significant strength loss.

I don't know which Zim it actually is, inherited a ziploc, and it strikes problem free without being buggy on its position in the production cycle. I've tried sys 96, premium 1.0, premium 2.0, and cristalica, but it spiderwebs them all.

That's kind of awful that sub par glass was the required expectation. I know when I need to get away with it, but that should never be a goal.

Pete VanderLaan 10-01-2019 12:43 PM

well, the actuality of it all was that not a lot of people knew how to make good glass. here was West Virginia and all that know-how and the attitude was never to ask them about anything. I always had a sense that it somehow violated the university sense of superiority as to how the material was treated. For Harvey and the whole first and second wave bunch- they thought they were special and needed to remain aloof. The name "bubble Chaser" was heard a lot. Having that big tank of glass thrown out was indicative of inability really.

Rob Adamson told me at one point when I was leaving Pilchuck that once upon a time there, it was really trying to learn and innovate on the basic level as well as the aesthetic one but it was cast aside. He loaded all the supplies from the dormant batchroom into my van and said it would never be missed. I think that was, and likely still is true. Once the first loads of Kugler came in at RISD, any interest in making decent glass stopped. There was no research into whether it fit anything and it was quite tolerant , given the lead content on most rod- not all as I'm cited before.

So, usage of batch materials was relegated for the most part to the private studios that were entreprenurial. Shops like Orient and Flume, Lundberg, Neurot. The Rocky Mts became the bastion of grinding and polishing mid '70's and all were derided by the schools with the exception of Penland and Alfred. When we put out the call for papers for the Hot Glass Information Exchange in 78, we sent that to every known Glass facility in the United States and only two schools responded to a direct call to share in the technical aspects of running a studio out of all of them. They again were Penland and Alfred. Both had representatives at one of the more interesting events I've ever participated in. For the schools, we were treated like lepers. .

Zimmermann made some phenomenal colors but had great difficulties with recurring stones and cords. Kugler danced around them with quality but never had the robust color Zimmermann had. The notion of expansion and adjusting for it really started with a Paul Manners article in '74 in Glass magazine and it was limited in scope as well as having some truly fatal assumptions about sources for factors. Those assumptions were reprinted in Glassnotes 3 which helped canonize bad info which was removed in Glassnotes4. Even today, it just amazed me how much poor information lurks in the various studios out there. I could go on and on but people tire of it. There's gobs of bad information out there today.

Shawn Everette 10-02-2019 09:34 AM

One of the reasons I'm actually glad to be in a private sector teaching institution is that I'm able to teach my way, instead of the nonsense academic rubric.

I'm actually really miffed at the quality of my undergrad photo education. They taught us all of the technical "magic" of the darkroom, but never how to properly light and shoot, because if you didn't take it in the moment it's not "Art". I just took a class on studio lighting, and it blew my mind that non of what I was learning was ever covered. Not even offered. Trying to figure out what I paid them for? Knowing what a daguerreotype is? It did introduce and convert me to glass, I guess I can't be that mad.

As we've discussed, there is a rift between the available education and the practical knowledge to run a proper studio. Or cook good glass. And people wonder why an BFA isn't worth the paper it's printed on. I'm actually please that my school is working on some professional development classes like, "how do you make a home studio", and "how do you sell your work". It's a shame, or sham, that nothing like that is offered at a university.

Pete VanderLaan 10-02-2019 11:53 AM

The schools in the 70's absolutely did not want individuals in their own shops. Their programs were justified by how full they were. One of my real incidents with Dale was at Pilchuck when I did a slide show on how to build a tank furnace. The dining hall was packed. Dale stormed in and began saying how stupid it was to want your own shop and asked repeatedly who could possibly want that. Silence. Then he knocked over the dais and said "So this lecture is over" and stormed out. I was totally humiliated.

But the part that truly pissed me off was how many people came up to me and asked if they could see the slides in private. Real heros.

Schools were really only interested in how you developed your portfolio. These days? The creation of the shop tech makes it harder and harder to learn any nuts and bolts at all. Art was the central focus and there's nothing wrong with talking art. Knowing your craft helps too. Schools have never put business classes in the requirements for a degree. Too bad.

Michael Ahlefeldt-Laurvig 10-02-2019 12:10 PM

So here we go again compatible issues, just cant understand, Ive been blowing glass for 29 years or so, and Iíve had one piece breaking unexpectedly
Ive done thousanda of cut off and polished pieces, Ive tried to estimate how many I have made, maybe 30000 Ive used Kugler Zimmarman Richenbach Only problem with opaque reds yellow and opaline white on small pieces
What is wrong in the US?
Nobody even think about it here, its a non issue, I canít understand what the problem is

Shawn Everette 10-02-2019 02:14 PM

So what kind of base glass are you using in Sweden? And is it commercially available? To the US?

I personally haven't come to have problems with cut and polish, but rather specific reds that are incompatible across the board.

Shawn Everette 10-02-2019 02:29 PM

That was a complete jerk move. Has a tendency to happen when someone thinks you're a challenge to their cash flow, or their ego.

One of my old studios was started because the "kilngons" wouldn't leave the program, most were too daft, drunk, or stoned to start anything on their own. That was a hell of entitlement and hillbilly rigging to get back on the tracks. Schools have gotten better about kicking the students out, not so much making them functional artists or fabricators.

There seems to be a perception in art school that if you teach someone to do something properly then you are doing them a disservice as an artist. There are exceptions. I did an anodizing intensive at Penland with Frankie Flood, when we talked about his programming one of his main goals was to make sure that if his students walked into a machine shop they'd be hired. They still get to make great art, they just have all the right training at their disposal. He's a hell of a great teacher.

Go ahead and break the rules, just make you know why you're doing it first.

Michael Ahlefeldt-Laurvig 10-02-2019 03:03 PM


Originally Posted by Shawn Everette (Post 145432)
So what kind of base glass are you using in Sweden? And is it commercially available? To the US?

I personally haven't come to have problems with cut and polish, but rather specific reds that are incompatible across the board.

Its Glasma, Ive used formula 33

Jordan Kube 10-02-2019 05:33 PM


Originally Posted by Michael Ahlefeldt-Laurvig (Post 145430)
So here we go again compatible issues, just cant understand, Ive been blowing glass for 29 years or so, and Iíve had one piece breaking unexpectedly
Ive done thousanda of cut off and polished pieces, Ive tried to estimate how many I have made, maybe 30000 Ive used Kugler Zimmarman Richenbach Only problem with opaque reds yellow and opaline white on small pieces
What is wrong in the US?
Nobody even think about it here, its a non issue, I canít understand what the problem is

The issue here is the Spectrum glass he is using. The glasses you mentioned are just fine.

Pete VanderLaan 10-03-2019 08:54 AM

I will always recall when Frank Wooley, Sr melt engineer at Corning who really knew his stuff became absolutely animated in agreement when I suggested at the 2001 Corning conference how frequently compatibility was mistaken for bad annealing.

It's still true. Short cycles with work put in too cold and being taken out too hot. It breaks glass. Our cullet circumstances and the voodoo beleived about those cullets contributes greatly to the American problem.

It is however worth considering that the bulk of American studios don't have these issues or at least don't have them for long before taking corrective actions. Then, there are the ones who insist on making the same bad assumptions again and again and experiencing the same results again and again.

It continues to go back to that wonderful scientific explanation I heard at Pilchuck one day:

"You can put the purple over the yellow but not the yellow over the purple. "

Pete VanderLaan 10-03-2019 09:17 AM


Originally Posted by Shawn Everette (Post 145432)
but rather specific reds that are incompatible across the board.

Most color rod has a 24% lead content and it allows for a remarkable amount of tolerance regardin mismatch except when you penetrate the surface tension of the piece as in sawing and grinding.

Reds and yellows are a different animal in that the presence of lead in the glass causes cadmium based colors to turn a shit brown. Selenium by itself is still clean with lead but not cadmium. So, those rods have zero lead in them and subsequently have no tolerance for mismatch. The Germans pretty much made those expansions down around an 85. The only cadmium rod that attempted working near the 96 quasi standard in the US is Gaffer. Enamel whites have about the same amount of lead in them plus about 6% arsenic which the EU is essentially banning in Europe. That is why the search for the titanium phosphate glass Peiser is currently pursuing is important. We did some work on that in my first color class here but Mark carried it on alone within about six months. I think he got up to 200 + melt tests. It is still really dicey to produce in any volume though.

Shawn Everette 10-03-2019 09:59 AM

Ok, so a true 96. Where the US when astray was trading convenience for constancy in some of its glass. Aside from misnomered System 96(94coe) the majority of the glass US blowers use hovers around a true 96 and poses little problems. When people start incorporating System 96, for one reason or another, people start having problems. It also doesn't help that the company has had a tendency to change the formula on a whim.

Honestly the System 96 nuggets are compatible enough that most people could work around issues. Because of free silica issues batch has not always been an option, so one had to decide between the cheap semi-compatible option, or the expensive compatible one. It WAS less costly, but with the move to Mexico that is no longer the case. Now it's really only a great option for people that want to do roll ups with system sheet, e.g. Charles W.

The majority of issues I have had go across the board for any base glass I can get my hands on. Specifically a kugler ox blood that will craze yet not break the surface, a kugler imperial red that would split everything cleanly down the middle, and a zim copper ruby that has a fairly even fragmentation.

Shawn Everette 10-03-2019 10:02 AM

What about the softer translucent whites? I tend to use those more for a opaline base.

Pete VanderLaan 10-03-2019 11:56 AM

As a generalization. Gaffer will give the best assurances on fit with a 96. There are issues with some phosphates, particularly containing copper which as an additive to glass has some rather unpredictable results. I make my own when I need it. The Bross formula is really a great place to start. It's not toxic and will teach your classes some pretty useful information, plus you get a good opal.

Shawn Everette 10-03-2019 12:44 PM

Yeah, I have had a bit of an issue with their phosphate opals and over working it, particularly a light blue. Other than white opaline they're not a large part of my pallet. There was a bag of 100 white that didn't seem to want to fully melt in. Compatibility was fine, but you could feel the frit on the inside of the piece. Kind of cool, but considering it was a lighting project it wasn't ideal. Other than those instances, and minimal batch fluctuations, gaffer's been fairly problem free.

Charles Willis 10-06-2019 01:31 PM

I'd like to thank everybody for their input. This situation has just taken an interesting turn. My partner called to tell me that one of his recent pieces exploded while sitting on the shelf. He was using Reichenbach for color. We'll be having a conversation with the studio manager about this. If we ever figure it out, I'll post back.

Pete VanderLaan 10-06-2019 02:46 PM

It's figured out.

Sky Campbell 10-06-2019 03:20 PM


Originally Posted by Pete VanderLaan (Post 145454)
It's figured out.

The sarcasm is priceless.

Rick Wilton 10-06-2019 04:14 PM

You can see stress in glass with something as simple as your cell phone and a pair of polarized sunglasses. It's really NOT that hard.

Pete VanderLaan 10-06-2019 05:04 PM

well, I agree. It's still helpful to identify the source though. Some of this is no longer rocket surgery. While I don't want to beat up on the folks just realizing these issues, there really are a lot of sources which should have put them on to it sometime back. There's really nothing new to see here. In this instant world, that should not be.

Greg Vriethoff 10-06-2019 05:30 PM

You don't have to distinguish between sheet and blowing nuggets when you're talking about Sys96. It's all the same failure.
I still maintain the "99 COE/LEC" should be confined to the nugget debacle.

Pete VanderLaan 10-06-2019 06:22 PM

That well may be true but if it is the case, it strikes me that the big sales pitch regarding the sys96 colors would be drop dead easy to match to the clear. That was the point.

If what you say is true, and the two are different, is it the case that the colors matched both glasses? One was measured at a 94.1, the other as you suggest is a true 96.

They should not fit each other if that is true. I do view .5 as a lot.

Terry Crider 10-06-2019 08:02 PM

This question is a little off from the rest of this thread, but it's might be of interest.
In the late 70's Frank Fenton gave me a list of exp. numbers a lot of their colors.
The test temp. range was 0-300C degrees.
Do have any idea how much difference there would be between this and the temp. range you use ?

Pete VanderLaan 10-07-2019 07:36 AM

300C is the gold standard. I would note that the testing I've done has been from 19C though. Getting your samples to stay at 0C is quite the chore. When Los Alamos labs did the testing of my dilatometer with me back in the late '90's, we did ice water baths with magnetic stirrers to try to get the tooling down to 0C and the numbers never made sense. It wasn't until the temperature that people in lab coats like to work in that we tried 19C and it all worked well and made sense. It's an important observation in that the testing Winkleman and Schott did for the enamel industry only went to 200C which was why the combination of those numbers with the English and Turner numbers failed. It's really the case now that the Appen figures are the best.

The dilatometer is not used much in the studio. John doesn't use it and I tend to if I know absolutely nothing about the glass in question. Otherwise the Hagy seal and the ring test provide excellent comparative numbers, one through gaps and the other through tension. Both ring and Hagy are problematic if the test glasses are off by much. They break. My goal in any test is to have all the indicators pointing in the same direction.

At that point viscosity becomes an important factor. The piece in question is I'm sure chock full of different ones.

Shawn Everette 10-07-2019 12:54 PM

It doesn't really make sense for spectrum to design a blowing nugget(system studio) to be used with their flat glass line, and then make a better blowing glass(system premium) not deigned to be used with their flat glass, yet to have the flat glass coe closer to the better glass.

If the flat was a true 96, then nearly everyone using cullet, including Charles, should be able to use it. Not to mention most of the people using spruce.

I've had 0 problems with the studio nuggets and the flat glass. I've gotten away with the premium and flat sometimes, but there were colors that wouldn't take.

Pete VanderLaan 10-07-2019 04:11 PM

How one melts makes a difference and it's not insignificant.

Back when I had the little studio in the Santa Fe railyards, I would melt on sundays and one pot was 275lbs of my clear and another was a 75 lb of a copper ruby. I would work both of those pots until midweek when at the end of the day, I needed more red, but the furnace was running at 2080F which is where I liked to work. I did actually want to go home so starting that cold, I loaded the red pot full of the batch glass. I did not return usually.

Now it's important to recognize that the red glass came out of the same batch barrel for both the sunday and the thursday melts. No changes. Identical mix from the same mixer.

The next day, I would use both glasses and the red was no longer compatible with the clear. This occurred several times before I started to dig in and change my process. If I turned the furnace up and waited until it was at least 2250F, there were no issues. It became clear to me how sensitive batch melts are looking at expansion/ temperature ranges.

The point there is that the two glasses are or were being melted in rather different environments, the big melter at Spectrum undoubtedly hotter than the Uroboros furnaces. It's worth considering. I don't ever try cold batch melts anymore unless they are fluorines with far lower viscosities.

Shawn Everette 10-07-2019 04:40 PM

I have no doubt that the way the nuggets are treated is remarkably different, or that the formula is tweaked from the base clear, I've melted the flat scraps. Just doesn't explain why system "96" sheet glass would be compatible with system "96" base cullet, with it's measured coe of 94, and not also be 94. If the sheet is a true 96, then why is it compatible with a 94, but not all the other 96 out there?

Sky Campbell 10-07-2019 05:06 PM


Originally Posted by Shawn Everette (Post 145480)
I have no doubt that the way the nuggets are treated is remarkably different, or that the formula is tweaked from the base clear, I've melted the flat scraps. Just doesn't explain why system "96" sheet glass would be compatible with system "96" base cullet, with it's measured coe of 94, and not also be 94. If the sheet is a true 96, then why is it compatible with a 94, but not all the other 96 out there?

The sheet glass was measured to be 94 not 96. The original studio nuggets was compatible with that sheet glass. The last spruce pine clone made by spectrum was 96 some colors work some will not. That is in my experience and testing from a trusted source.

Pete VanderLaan 10-07-2019 06:21 PM

Best not to sell the pieces made from it. If you do, they'll break for sure. If you make some butt ugly stuff with it, it will last forever.

Greg Vriethoff 10-07-2019 06:35 PM


Originally Posted by Sky Campbell (Post 145481)
The sheet glass was measured to be 94 not 96.

Okay, Sky. Thank you for answering my question.

I'll stop questioning the irrefutable truth.

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