Glass Line
June/July, 1996. Vol.10 No.1


by Robert A. Mickelsen

***** Lampworkers Having Babies! *****

I have to begin this column with two joyous announcements! On April 19, Brian Kerkvliet and Alexandra King celebrated the birth of their daughter, Marissa Celeste. They had Marissa at home and everything went perfectly. Congratulations Brian and Alexandra!!!

On April 27, Marc Petrovic and Kari Russell-Pool brought into the world their new 8 pound, 14 ounce baby daughter, Phoebe Robin Petrovic. Congratulations Marc and Kari! This has been an eventful spring for Kari. Not only is she a new mother, but the latest issue of Glass Magazine featured her and her work in a beautiful four page spread and a generous review by none other than Ginny Ruffner herself! Kudos for Kari!

Is it spring or what?

***** Chem-O-Lene Revisited *****

As you may remember, a while back I reviewed a remarkable product called Chem-O-Lene that acted as a booster to propane. I described how it made a hotter flame than plain propane and oxygen and could potentially save on oxygen use. I also described some of the problems I encountered and said that I would let you know how these problems were solved. Well, the verdict is in and I think I can safely say that this product is worth its cost.

I received a replacement bottle on October 20, 1995 and hooked it up that day. I checked the bottle on 2/14 and it was still nearly half full. I just checked it again tonight (5/23) and it is finally nearly empty. I have used 185 gallons of propane during this time so it appears that their claim that a full blender will treat 600 pounds is bona-fide since a gallon of propane weighs about three pounds. I still stand by what I said in the earlier column that the difference, while significant, is not overwhelming. The only benefit for procedures that do not require more heat than plain propane can give you is in a barely- noticeable savings in the consumption of gas. It is when you are maxed out and want more heat that Chem-O-Lene really shines. For this reason I suggest hooking the blender up to your gas lines with a two-way check valve that will allow you to route around the blender when you do not need the extra heat.

Ricky is now including much more information with each blender than he did at first. Most interesting is a comparison of fuel gas properties, a sheet of test results that shows conclusively the exact nature of the benefit afforded by Chem-O-Lene. I found these stats to be fascinating and graphed the most significant for you.

 I found these stats to be fascinating and graphed the most significant for you.

The first thing you will notice is the dramatic difference in flame temperature. The Chem- o-lene provides a 1200 degree boost over untreated propane or natural gas. This very nearly equals acetylene and surpasses Mapp gas! Only hydrogen would burn hotter. The second chart shows the combustion heating value of the gas. This is broken up into three values: primary, secondary, and total. The primary and secondary values refer to the primary and secondary parts of the flame. The inner blue cone's are the primary and the outer blue working flame is the secondary. Note that the secondary flame has a far greater combustion heating value than the primary. There are some surprises here. Notice the low values relating to Acetylene. This is because the unstable nature of Acetylene means that delivery pressures cannot exceed 15 pounds. Even lower is natural gas because of the very low delivery pressure of natural gas lines. The manufactured gasses propane and Mapp gas fare much better, but towering above them all is Chem-o- lene.

So what does it all mean? Simply that Chem-O-Lene burns hotter and heats more efficiently than untreated propane or natural gas and is much more stable and therefore safer than acetylene. With Chem-O-Lene, there is not as high a carbon content so there is a lower level of hydrocarbon contaminants, that nasty stuff that piles up on your torch tip. There is a much lower danger of backfire because of the lower combustion ratio. Chem-O-Lene should realize a 20 - 25% savings in oxygen use which could go a long way towards paying for the blender, and it will allow you to work hotter, longer, and potentially larger and faster. For me, it makes enough of a difference that I feel that I earn back the cost of the full blender every month! I guess you could say that I am sold on it!

To order Chem-O-Lene contact:
Rick Dodson
4403 Hank Avenue
Austin, TX. 78745
(800) 670-GLAS or (512) 444-8712

***** The Best Bead Show *****

Renowned teacher and philosopher of bead making Lewis Wilson and his wife Kathy have expanded their interest in the bead world with their first ever bead exhibition. They named their show "The Best Bead Show" and scheduled it to occur in the middle of the annual Tucson Gem and Mineral Show which draws nearly 500,000 people, including 30,000 wholesale buyers, to Tucson every year. They held it in the Southwest Center for Music and invited the top names in bead making. True to Lewis' usual style (never doing anything halfway) they spent a small fortune on promotion taking out three page ads in Ornament Magazine and Lapidary Journal, producing a video featuring work from every exhibitor in the show, printing a large poster with a bead from every exhibitor and running ads in every local publication for weeks before the show.

Lewis and Kathy spiced up the event with a champagne gala opening complete with a ribbon cutting ceremony and a string band and kept up the festivities throughout the six days of the show with a wide variety of eclectic music made all the better by the wonderful acoustics in the Southwest Center for Music. The atmosphere was congenial and inviting and the attendance was excellent. But rather than trying to pontificate further about an event which I was not able to attend, allow me to repeat for you some of what a few who were there have said.

Kristina Logan claimed the show was "successful in all regards". "Attendance was good and sales were very good. Lewis went wild with his promotion of the show and the results for me showed that it really paid off. I loved the music they played and it sounded so good in that building! I have already signed up for next year."

Loren Stump told me he sold completely out in the first three days of the event. "Lewis delivered on all of his promises. I think he spent more money on promotion than any show I have ever been associated with. There was a steady crowd for all six days and the atmosphere was relaxed and friendly. I had a great time. I heard more than one exhibitor say it was the best show they had ever done."

Brian Kervleit was a bit more reserved. His said his sales were just so-so, and that there were a lot of lookers. "There were a lot of people there to whom this was a new experience. They were there for the gem and mineral show and glass beads were something they were not that familiar with. This was a good educational experience for them. I think that the lower priced beads sold better than the high-end stuff. Overall though, this was a good first-year event."

Paul Trautman (NorthStar Glassworks) was not an exhibitor but attended the show and had a few comments. "What I saw was simply the finest collection of lampworked beads I have ever seen. The quality of workmanship was unsurpassed! The show had a relaxed joyful feeling, and the atmosphere was welcoming and inviting rather than stuffy and sterile like in some of the other shows. It was well-attended and I got the impression that a lot of people were doing very well."

I was hard pressed to get anyone to complain about anything. After some prodding Kristina finally told me that she would have preferred some space between booths and that she was uncomfortable with booths crammed side-by-side like that. Brian thought that there could have been more outdoor signs around town to direct people to the Music Center. But the overall consensus seems to be overwhelmingly that the show was a smash success and that they would all be back for more next year. Congratulations Lewis and Kathy! Looks like you pulled it off!

***** Czech Glass *****

I got a phone call several weeks ago from my old friend Therese Lahaie who used to work as a sales rep for C&R Loo. She retired about a year ago, but has since come out of retirement to work for a company called East Bay Color. East Bay is importing glass rod designed for lampworking from the Czech Republic (formerly Czechoslovakia). The glass has an expansion co-efficient of around 104 which would make it compatible with Moretti. Therese asked me to test some samples for compatibility and workability. Since she had also asked Brian Kerkvliet to do tests for compatibility with Moretti, I decided to stick to testing for compatibility among the various colors of the Czech glass.

I did more than a dozen tests and could find no problems anywhere. Not only that, but I called Brian and he told me that his results were consistent with the factory specs. He found that the glass matched well with Moretti, although he thought that some of the transparent colors were a bit pale. Of greatest interest was the Czech clear glass rod. As anyone who has worked with Moretti clear knows, clear rod is very prone to devitrification. Many lampworkers use the pale blue and yellow for casing instead of the clear because of this. The Czech clear was not at all prone to devitrification and in fact was an excellent quality glass. However, the first samples tested by Brian had a COE of close to 114, too high to be considered compatible with Moretti or even the rest of the Czech colors. Therese contacted the factory and supposedly they have solved the problem with the latest batches of clear, and East Bay should have stock by the time you read this.

Overall, the colors are very similar to Moretti, and although the palette is a bit limited now, they are working on many more new colors including a whole line of opalescent colors. I was presented with a sampler of 22 basic transparents and opaques. I found the colors to be strong, stable, and very workable. The rods are a little thicker averaging 8 - 10mm which makes it a little trickier to heat up but much easier to get a quantity of it going than if the rods were 6mm like Moretti. In my opinion, this is an excellent quality glass that would make a fine substitute for Moretti. If they can make the clear work and introduce some new colors that Moretti does not have, their place in the market will be assured. Therese says that the price-per-pound will actually be lower than Moretti making this an attractive product indeed. For more information contact:

East Bay Color
169 South First Street
Richmond, CA 94804
Tel/FAX: 510-233-0708
Tel: 510-233-1800
1-800-EB-COLOR / 1-800-322-6567
(ask for Therese)

***** GAS *****

It's that time of year again. By the time you read this, it will be over, but right now preparations are in full swing for this years Glass Art Society conference. This year, it is in good old Beantown! I have not been to Boston for eighteen years and I am really excited about returning. High on my list of things to see is, of course, the Harvard Glass Flowers at the Peabody museum. This collection of Botanical models was commissioned in the late 19th century by Virginia Ware to Rudolf and Leopold Blashka. They used lampworking, enameling, and many ingenious and long-forgotten techniques to build these incredibly life-like models. They are so realistic, that you cannot tell by looking at them that they are not real flowers! Also high on my list is the flameworking show at the Society of Arts and Crafts. This exhibition will feature eleven of the finest flameworkers in the country and will run for several weeks before, during and after GAS. Not only that, but the flameworker show is the third stop on the "Elegant Evening" collector's tour. Collector's will pay $500 for an entire day which consists of glass blowing demos, a tour of the Glass Flowers and will culminate their day at the Society Lampworking Show! Some of the artists exhibiting in that show are Fred Birkhill, Shane Fero, Ellie Burke, Sally Prasch, Suellen Fowler, Brian Kervleit, Hans Frabel, Emelio Santini, Kari Pool, James Minson, and Me! There is also a bead makers show in the Society's Arch Street Gallery that includes Tom Boylan, Julie Clinton, Kate Fowle, Patricia Frantz, Shari Hopper, Mary Kennedy, Kristina Logan, Rene Roberts, Don Schneider, Alison Sheafor, William Stokes, and Loren Stump.

This year, the list of demonstrating lampworkers is very long. On Thursday, Fred Birkhill, Stevie Bell, Shane Fero, Brian Kerkvliet, Patricia Frantz, Will Stokes, Andrea Guarino, Doni Hatz, Bandhu Scott Dunham, Loren Stump, Emelio Santini, Ricky Dodson, Kristina Logan, Dinah Hulet, and I will each do demos. Then, on Friday, Sally Prasch, Kari Pool, Kevin O'Grady, Lewis Wilson, Julie Clinton, Heather Trimlett, Don Schneider, Jenny Pohlman, Don Niblack, Alison Sheafor, Gus Able, Roger Parramore, Dennis Briening, Meg Wenzel, Milon Townsend, and Sabrina Knowles will be 'workin for nothin'! That is a LOT of flameworking demos, and while I am delighted that flameworking is getting so much attention, I am a little concerned about possible overkill.

Because it doesn't stop there. There are pre-conference workshops too. There are five: Conceptual Voyaging Through Lampwork by Bandhu Scott Dunham and Sally Prasch; An Eclectic Approach to Flameworked Glass by Fred Birkhill and Shane Fero; Glass Beadmaking Workshop by Andera Guarino and Doni Hatz; Soft and Borosilicate Glass for Advanced Artists by Emelio Santini and Lisa Malchow Allen; and Glass Beadmaking Workshop by Kristina Logan.

Then there are the post-conference workshops: Exploring the Human Figure by Ricky Dodson and Milon Townsend; Heat, Breath, and Shape - An Introduction to Flameworking by my wife Shelia and I; From Borosilicate to Soft Glass - Stepping Beyond Simple Beads by Don Schneider and Alison Sheafor; Glass Beadmaking - Comprehensive Beginning and Advanced Technique by Sabrina Knowles and Jenny Pohlman; and a class combining flameworking and glassblowing by Don Niblack and David Wilson. Think that's too many? Well, they are all full a month before the conference! In my next column I will let you all know how it all went.

***** New Glass! "Soft" Borosilicate!! *****

I have been saying for several years that I thought that the next major innovation in lampworking would be in the material we use. Most of us use borosilicate glass like Pyrex which was designed primarily for laboratory use, not for artwork. The remainder use soft glass like Moretti which has many limitations due to the extremely high expansion coefficient and sensitivity to thermal shock. What we need is a glass that has sufficient resistance to thermal shock so it won't limit our artistic expression, but is soft enough to provide superior workability, longer working time, and some decent FLOW! Well, the time may have finally come!

I recently had a talk with Victor Trabucco, a master paperweight maker and glass sculptor who has developed a glass that may be the future of lampworking. Victor had recently sent me a couple of short pieces of " rod that did not look like anything special until I heated them up. When I did I thought I was working with soft glass! But Victor had told me it was compatible with Pyrex and when I tried fusing them together, they were! I could not believe what I was seeing! I had always thought that a relatively soft glass might be able to be produced that had a relatively low COE, maybe something like 45 or 50. But a soft glass at 33!?? That was just too good to be true.

I did a number of experiments using Pyrex, Duran and NorthStar and the mystery glass matched them all perfectly. I knew that this was something very exciting, so I called Victor back and we did a little interview. Instead of hearing about this remarkable product from me, I thought it would be better if you hear it from Victor. A transcript of our conversation follows.

RM: Victor, what is this new glass called? Do you have a name for it yet?
VT: The name I thought we might use is "Crystal Clear-33". The expansion should be somewhere around 32, 33 or 34. Whatever it comes out to be will be the name. But "Crystal Clear-33" is basically what I thought would be an appropriate name.
RM: That is an appropriate name. It's a really clear glass, at least the samples I've seen have been. It's a borosilicate glass, correct?
VT: Yes.
RM: Can you tell us what makes it so different from other borosilicates?
VT: Basically, the softening point is lower, which helps in working and sculpturing it because it doesn't take as much heat to soften it. This helps to not break down the surface. You have less devitrification. You can work larger pieces. The glass blows better. It has a little longer working time so you don't have to re-heat as often. We just talked about the color being a lot clearer. There's very little, if any color to it at all.
RM: So actually the melting temperature is lower.
VT: Yes, the softening point would actually be lower but the annealing temperature would be very close to the same.
RM: Well I can certainly verify that the couple of samples that you've sent me matched perfectly. I tried it with NorthStar, I tried it with Pyrex, I tried it with Duran and it fit perfectly as far as I could tell.
VT: Yeah, I've checked it in a polariscope and everything and there is very little strain so it should be no problem at all.
RM: Can you describe for us what specific advantages that would give a lampworker over, say, Pyrex brand borosilicate glass?
VT: Well, basically the reason that I pursued this was that I've worked with soft glass and with Pyrex for a number of years and I wanted to combine the qualities of each. Soft glass is a lot nicer to work in a torch once it gets warm. You don't have to drive so much heat into it to make it move. Pyrex is really designed to be more chemical-resistant so hardness was a feature they were trying to build into the glass. It doesn't really serve any purpose for artistic use so that was something I was trying to eliminate. But I wanted to retain the resistance to thermal shock that Pyrex has.
RM: Well it certainly makes it more difficult to color the glass. In fact that is one of the applications that people are very excited about. With the lower melting temperature and a softer glass it would be much easier to make colors.
VT: Right. I'm working and talking with Paul Trautman from NorthStar about that and he's expressed a lot of interest. He is going to be getting a lot of the material in cullet form and he's excited about producing some new colors. Because of the fact that you have a lower softening point the colors won't tend to burn out as much.
RM: And they'll be much nicer colors. You know many of the colors that he has have a high metal content like his exotics and the cobalts that are so viscous that they are difficult to work with. Maybe this would make them a little softer and easier to work.
VT: That will all come into play.
RM: I'm very excited about it myself. I have mentioned this to a few people just to gauge their reaction and the reaction has been almost universal excitement. Everybody is excited just to hear that such a thing as a 'soft' 33 expansion glass is possible to make.
VT: Well it is possible and we have produced it. It is just a matter of getting to the point where we can produce it consistently and be able to sell it at a price that everyone will be able to use it.
RM: Do you think it will be comparative in price to borosilicate glass?
VT: Well, we certainly can't compete with Corning or Kimball because of the quantities they are able to run. I hope to be able to sell it at a price that the artistic lampworkers can afford.
RM: Any chance that this glass will be available in tubing form?
VT: We are certainly keeping all those possibilities open. Primarily, we want to get the rod created first and down the road look at tubing as a possibility.
RM: Who do you have lined up to do the production?
VT: At this time I am keeping that confidential. I have actually been working with a couple of firms. I just have to work out a couple of technical snags and once that is resolved it should be out there ready for sale.
RM: Great! I hope the reaction is strong! I have one more question for you. The formula for this glass, is this something that you yourself came up with? Is this a Victor Trabucco invention?
VT: Well, I've worked on some of the factors in it and I did work closely with this company in producing it. I did have a lot of input on the actual material itself. I do have the formula and I am just hoping we don't have any technical problems as far as the final production of it is concerned.
RM: I hope so too because I am excited to get my hands on more of it. Thanks for talking to me Victor!
VT: Thank you, Robert.

Since our conversation, Victor has told me that most of the technical problems have been solved and they are very close to production. In fact, by the time this sees print, the glass could well be available. When it is, I will put a notice on my web page with the address and phone of who to contact for pricing and ordering. (

Well that's it for this issue campers. I have no idea what I will write about in the next column. If you have anything you would like to contribute, you know where to find me. Until then....... keep it hot!

Robert A. Mickelsen
265 Rita Blvd.
Melbourne Beach, FL. 32951
(407) 723-5376
internet email:
CompuServe email: 71042,751
world-wide web:

 Photo of... Montage Warrior Bottle
 Photo of... Piper at the Gates of Dawn
Montage Warrior Bottle 1996
by Robert A. Mickelsen

16" tall borosilicate glass, northstar colors, montage technique, blown and sculpted.

Photo by Dan Abbott
Piper at the Gates of Dawn 1996
by Robert A. Mickelsen

21" tall borosilicate glass,
northstar colors, blown and sculpted, etched imagery done on computer and sandblasted using photomask.
Photo by Dan Abbott
 Photo of... Arbor Spirit Bottle
 Photo of... Lust Angel
Arbor Spirit Bottle 1996
by Robert A. Mickelsen

14" tall borosilicate glass, northstar colors, blown and sculpted.

Photo by Dan Abbott

Lust Angel
by Robert A. Mickelsen

15" tall borosilicate glass, northstar colors, blown and sculpted, etched imagery done on computer and sandblasted using photomask.
Photo by Dan Abbott

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Last Modified: Saturday, 07-Feb-2009 06:59:32 MST