(Note - this Substack blog is for more than just my glass flute pursuits, despite the name. I just posted this text and image as the content at my laurentflutes.com website. Enjoy!)
Here is a status update and other thoughts on this project.
Currently I am working mostly on my wood flute queue and other matters, and hoping to have more time to work on the glass flute project in the warmer months. My initial attempts at working with glass in any form, and some of the materials used for casting or cold finishing tells me that I need to set up proper dust collection and removal, etc. I still have much tooling up to do and a workspace to organize.
In the next month or two I plan to get the metal work underway. I will probably 3D print masters for the 4 keys and their bases, as well as the head joint ferrules and other parts. These will be sent over to the casting service in Seattle for molding and casting in Sterling Silver or Silicon Bronze. Note that the original ferrules were in bronze, which were then plated by rubbing Silver Almagam (Silver and Mercury) on the surface, and then roasting off the Mercury! This leaves a surface that is almost pure silver which has a slightly darker aspect to it than Sterling. Some of the ferrules and mating slides will simply be fashioned from sheet or tubular silver or nickel.
Next I will finally render a design that can be 3D printed. I have to relearn how to do this - it has been awhile. I will probably aim for a simple, unornamented design as was done in some of the earliest Laurent flutes. Otherwise I will go for a very shallow fluting, or faceted surface. The reason for this is to maintain some sort of mass. The plastic resins have proved to be archival enough (not surprising since these are the same kind used for dental fillings). The density is similar to Boxwood or heavier. These plastic renderings will be easy to produce. I hope to find some clear resins that have a similar index of refraction as the glasses used by Laurent. One challenge that remains is how to achieve a decent finish on this material.
There is a major push to 3D print woodwinds underway, including another bagpipe maker in Seattle. The Silverwork is no difficulty. Thus reproducing these flutes in Plastic and Silver is well within the capacity of several makers. Data on the flutes themselves is required. Eventually I plan to release sufficient data once I have achieved my results in glass, or plastic if that is all I achieve.
I currently have enough data on several flutes, including one that plays superbly that is nearby, to make a reasonable copy. Once the Library of Congress opens and it is safe to travel, I plan to go there to measure the Madison flute and other Laurent Flutes in the Dayton Miller Collection.
Then comes the glass rendering. I have identifiued two traditional approaches that were used by Laurent's glass workers that will be attempted eventually. I will also be using techniques that are used in amateur telescope making. All three techniques are accessible and in this Age of Glass, easy to learn or access.
The first of these techniques is simply glass blowing, followed by cold working. It is clear to me that the glass was gathered and then blown into a tube. One can see elongated and pointy ended bubbles aligned with the axis that results from this technique. There are a few variants. This can be done simply freehand and the glass roughed to shape with a narrower bore and larger outer diameter by careful gathering and marvering. A simpler and more direct technique would be to simply blow into a mold, as is done with bottles. Probably the best approach is to partner up with a glass blower and commission the roughed out tubes.
A few of Laurent's flutes were cast in Cobalt Glass. In these the bubbles are numerous, including on the surface of the glass where these leave pits. The bubbles are circular. Glass at the casting temperatures is still relatively viscous and its nearly impossible for the bubbles to escape unless one leaves the glass at the casting temperature for a long time. There are also some techniques used where a glass rod of sufficient quuantity is melted on one side of a U-shaped chamber with the other side being the mold. I actually sized my casting kiln to have this capability. The bubbles are mostly eliminated.
Casting requires the ability to make waxes. One common approach is to make a master which is then silicon molded. Casting wax can then be injected, invested and then usually steamed out of the mold. I tried working directly with these waxes instead of mastering and molding. I did find a wax that machines well that is used in industrial and jewelry casting. However it melts out at 260F. I haven't tested this wax to see if it would leave a residue. Theoretically any residue can be dissolved out by Acetone. Its important to remove any residue otherwise this promotes devitrification - a condition where the class attempts to return to its original components! This is wh
y the glass casters prefer to use a wax than can be steamed out of the mold. Assuming I can get this wax to work, I can theoretically render a flute body with tone holes etc. and greatly reduce the amount of cold finishing required. Another way to do this sans equpment and learning curve is to simply 3D print a master set and send this off for molding, and then casting from that mold. There are a few glass arists who provide such a service. The cost per silicon mold according to one caster, would be around $800 - thus $3200 for an entire 4 section flute. This could be reduced to $2400 by casting the lower middle and foot joints as one casting which is then separated later. The casting cost would be $200 per section, thus $600 to $800 per flute.
Both of these methods will require cold working. This is simply grinding the surface of the glass to its final shape using abrasives and abrasive edged tools. A cast iron mandrel with abrasive slurry to 300 grit renders the bore. The outside shape can be ground to shape using a lathe with a template guided grinding wheel. Or one simply can use one of the large horizontal grinding wheels combined with lapping belts. The outsides of the body joints appear to be straight tapers with a small degree of flaring upward. The head joint is slightly convex. Anyone familiar with lapidary work will easily adapt to these techniques. I've been told that its best to stay above 150 grit as coarser grits can cause surface microfracturing.
Of course, all one has done at this point is produced a tube, or a tube with roughed out tone holes etc. With blown glass one can then do the faceting or fluting using a glass engraving lathe. Tone holes can be drilled using diamond drills. Undercutting of these holes can be done with a copper tool that is internally threaded that can be picked up by a threaded rod similar to the Fraises used by some flute makers in the past. This will require some skill and finess. I don;t know if I have enough time left to develop these techniques so casting seems like my best approach glasswise!
But then, why not simply render the tube from a piece of solid glass rod? This material is available locally from such sources as Olympic Color Rods. Prepare for sticker shock. Producing art glass requires lots of energy and Putin's Warmongering has dramatically increased the cost of this mayterial, which is made in Germany and elsewhere in the Europe! In my usual overexuberance I spent some considerable money on glass last year - and am now glad to have done so!
This is what I plan to do to render this glass into tubular form. I will cut the pieces into lenth, and then wrap the cylinder with duct tape to hold it all together should it explode. This will be chucked into my boring lathe with its 2" ID head stock. Instead of the usual gun drills, I will use something called a Diamond Disintegration Drill which is applied with a coolant. These are simply a tube with and slightly larger in diameter diamond-impregnated sintered bronze end similar to a diamond core drill, except that the end is a solid surface widepth th an offset hole for the coolant. Theoretically these will drill about 1cm in a miinute. The bore can be step bored. And then, similar to the other techniques used, the bore shape will be achieved by grinding to shape with a cast iron tool and abrasive slurry. I might also obtain some roughing "reamers" with a diamond-coated surface from the same company that made my drills (National Diamond Laboratory in Los Angeles) which will accelerate the process.
Then comes the outsides! I plan to use a Gorton Pantograph set up with a small lathe on its table. As the glass rotates, a horizntally spinning diamond wheel starting at 180 grit will grind the surface to profile, guided by a template on the stylus table. One can do a similar setup by mounting the diamond wheel on a milling machine and rotating the flute body on a lathe mounted to the table. Because the shapes are close to straight tapers this could be easily accomplished. The advantage of the pantograph approach is that this can be set up for self feeding for each cut, with a self shut-off. One will still have to do the final grind and polishing and acoustical work.
In my enthusiasm I did get one of these Gorton P1-2 Pantograph mills. Moving this 640 pound beast took much longer than expected - I had to tear the machine down to its individual compomnents, leaving the heavy base that I moved using a UHaul truck, with a forklift on one end and a Kubota Tractor with forks on the receiving end to get this into my workshop where it currently remains disassembled. I could opt for the simpler milling machine method except I would wear out my hands cranking the table back and forth!So that machine was an okay investment. If we decide to move, I will hire professionals to move that and all of my other machinery - assuming I don't downsize my career!
So there. I have thus so far accomplished much on this project by discovering potential paths that any flute maker could pursue, to render copies of Laurent's flutes. There is certainly a market for well-crafted copies and I intend to provide the Library of Congress with one based on Madison's flute. This way they do not need to loan the original for any kind of performing purpose. I hope I have the time and energy in my career life to pursue this. I have considered fundraising but am better off without the associated stress.
How this project got started: a local glass worker specializing in high-end optics and I have been discussing rendering these for over a decade, using his technologies. That seemed to never go anywhere. In 2013 and since I gathered data on these flutes, enough to render a copy in wood. In 2018 I got wearly of hand forging keys and discovered Alchemist Casting in Seattle who now cast all of my flute keys. A number of other makers are now using their artistic output. They have 3D printing capability for mastering and molding. However, their queue can be several weeks and so I considered mastering myself, and was delighted to discover that the higher resolution liquid resin printers were affordable and easy to use. For designs I discovered ShapR3D for the iPad which is much easier to learn than all the other CadCam programs. And then Grey Larsen asked me if I was planning to 3D print some flutes!
I had never considered it! I drew up a simple foot joint - since the Z axis length was only 160mm. After drawing these up and printing a few, I added fluting similar to that used on Laurent's flutes. I then rebuilt the printer for a 350mm Z-axis and rendered my 3 piece Folk Flute on these. These flutes actually worked well and this is something I will be pursuing as well. And then a flute player in New York contacted me and offered to send me his Laurent Flute to see if I culd render a new foot joint at least in resin - as hos flute was otherwise unplayable. The flute serves as a handy bit of reference. I then got thinking - well how hard would it be to render the new foot joint in glass. This is when I got into this trouble. I just officially achieved retirement age and am not so sure I am up for pursuing this all the way to its logical end point of producing several of these flutes in glass, after 40 years of flute making!
At least I have made it this far on this path of discovery. I tend to share my secrets and thus if there are other flute makers out there who are interested in pursuing this, please contact me. (Updated March 12, 2022)