Sleeving the Upper Joint of a Clarinet Part 2: Graphite Banding

With the sleeve in place and the bore restored to a consisent and concentric shape (see previous post) I moved to the outside of the instrument. The two enormous cracks running down either side of the upper joint could still leak or even continue to grow, especially with a plastic liner that expands at a different rate than wood with temperature and humidity changes. While I usually choose to pin cracks because of the relative ease of installation and minimal cosmetic damage, that wasn't a feasible option in this case. Drilling holes for the pins would have required going through wood, then plastic, then wood again, and since different speeds are necessary for drilling plastic and wood there was a good chance of either overheating/burning the wood or melting the plastic. So installing bands, while more cosmetically disruptive, made a lot more sense. If you saw the previous post about this instrument, you saw that it came in with metal bands installed, which is an older method of doing this repair. However since the development and proliferation of graphite ribbon, sometimes also referred to as carbon-fiber, that's become the preffered material for banding. It's easier to work with and slightly more flexible than nickel, so there's less chance of it causing the bore to constrict as the wood expands and contracts over time (as had happened with this instrument).

Ideally I would have cut the channels for the bands deeper than in this example, so that they could be installed below the surface and covered with mixture of super glue and grenadilla dust, a technique I first heard about from a technician in the UK named Chris Peryagh. But since a lot of wood had already been removed from the inside of this instrument, I tried to minimize the depth of the channels and therefore keep as much wood as possible between the band and the sleeve.

Before cutting the bands, though, the top three tone holes had to be re-drilled since they were covered up by the sleeve. Cutting a new tone hole would ideally be done on a mill to ensure an absolutely straight and level cut with an even pad seat. In this case since the top half of each tone hole was still intact I was able to use that as a guide for drilling out the sleeve on a drill press.

Re-drilling the C trill tone hole. Do you like my expertly constructed clamping jig?

Wax is applied to the outside of the joint to prevent epoxy from sticking to the surface. That's the goop you can see in the top couple tone holes.

Next the channels were cut on the lathe to .040” deep. Epoxy will adhere in the channels since the waxed area was cut out.

Strips of graphite are pulled from a ribbon, approximately the same diameter as the channels. They're coated in a generous amount of plain old 2-ton epoxy. The strips are laid into the channels and pulled snug but not tight, to avoid constricting the wood. Although, that's less of a concern on this instrument since the plastic liner is less likely than wood to buckle.

After the epoxy is dry the excess is trimmed on the lathe, but not all the way to the surface. The outside of an instrument is rarely concentric with the bore (eccentric), and that's even more true of this instrument than most, so final cleanup will be done by hand.

The rest of the excess is filed off, then sanded until the bands are flush with the body of the instrument and the surface is smooth.

Finally the joint can be oiled. This is only done after the bands have been installed so that the oil won't interfere with the adhesion of the epoxy. After a week in the immersion oil bath, this joint is ready for key fitting and padding.

The joint was immersed in oil for a week, then allowed to dry for about 3 more weeks so it had a chance to fully absorb as much oil as it needed. This is how it looked at the end of that process.

After all of that was done, I ventured back in to Philadelphia to visit Mark Jacoby again, who has a set of factory reamers designed especially for cutting the necessary tapers in a clarinet. Actually, before taking on this project I didn't know that the upper joint of a clarinet is tapered at all - another thing I learned from this process. On this instrument, as with many others, there's a slight reverse taper in the top of the upper joint that transistions into a short straight section, then back out to a taper. Since the bore of the insert was cut straight on the lathe, reaming restored that original taper. No pictures of that process, sorry.

After installing all new pads and corks and making a lot of fine adjustments, this instrument has a new lease on life.

One last before-and-after, how the instrument looked when it came in, and just before packing it up in the case. 

Buffet English Horn Bonus Post 3 - Bore Repair

Prologue: I didn't do this repair. In this scenario, for once, I was the customer. David Teitelbaum did this work, and reminded me of my vast appreciation for the skills of more experienced and seasoned technicians like him. His skills and the quality of his work made the full restoration of this instrument possible. Beyond that the insight he provided into his process was immensely informative as I worked on the clarinet bore sleeve detailed in this recent post. More on that later...

Rebuilding my personal english horn was a labor of love. But it was also a labor of wanting to have a functional english horn. So after putting in that time making parts and sealing cracks and fitting keys and replacing pads and corks I ended up with an instrument that was playable. Technically playable. But it was only after putting in all that work that I looked for other underlying problems. My approach is not always methodical.

I'd observed that something was weird with the bore upper joint, but I see lots of weird stuff and didn't worry about it. Turns out I should have. The more I played the instrument, the more it seemed to misbehave. Low notes would growl as if trying to jump the octave. High notes were difficult to bring up to pitch. Intonation throughout the instrument was very inconsistent. In searching for the cause I found a crack in the upper joint that was causing problems. After that was pinned and sealed the whole range became a little easier to play. Then I made a new octave mechanism on the suspicion that the original, convoluted mechanism was causing the octave pads to not seal. That made the low notes more predictable, but not great. Something still wasn't right. Something was still horribly wrong. I continued to recheck the pad work and regulations, making adjustments wherever possible. It was a shot to my ego to not be able to play an instrument I'd put so much careful work and dedicated so much time to.

All along that weird spot in the upper joint was in the front of my mind. I knew it was probably the cause of all those problems, but was reluctant to face that fact after putting in so much time on the rest of the instrument. What if it couldn't be fixed and all of that work was for nothing? How could I have been foolish enough to put in all that work while overlooking something so serious? But like a papercut, you can't look away and wince forever. Eventually you have to open your eyes and inspect the damage. Then you get someone in New York to make you a new thumb and graft it on. Nevermind, the analogy kind of breaks down there.

Really taking a close look and seeing how horribly the bore had been gouged out I felt at once exasperation and relief. Exasperation at having my fears confirmed, that I had put so much time into an instrument with such a glaring and fatal problem; relief that maybe my work didn't suck so much after all. It looked like someone had gotten a swab stuck up there and had just gone to town with a screwdriver trying to get it out. (When David called me with his assessment, he said it looked like someone had drilled it out.) It was a surprising amount of damage. The fact that the instrument played at all was remarkable.

I was in a tough spot because I strongly suspected that this repair was beyond my abilities. (Hindsight: Yeah, it totally was.) But I had put a lot of time and effort into this instrument, and wasn't prepared to let it be a total failure yet. Fortunately a conversation with another oboe technician yielded the good news I needed: it could be fixed, but there were only two techs in the US who would attempt it. He advised calling David Teitelbaum.

So I called and shipped it off. David called me when it first arrived at his shop to talk about how intensive the work would be and the likelihood of success (he was cautiously optimistic, but I had the utmost confidence), and then I just sort of waited for another call. This was the first time I've been an instrument repair customer in at least a decade and it was unusual. Usually I know exactly what's going on with a repair, but this time, with my own instrument, I just knew that it was in the shop and would be done at some point and would play better than it had. I hate not knowing, but the experience was a reminder that I need to do a better job communicating with my customers about the progress of their repairs.

Skip to five weeks later and I got another call that the repair had been a success and everything was good to go. A few days later I was playing it and it was thrilling. David took the instrument and brought it back from the brink of uselessness. Where before I could sort of muscle my way through some passages, now it just plays. It plays easily! And consistently in tune! It's a powerful instrument. There's not a great deal of depth to the sound, but it will really project through an ensemble texture. And whatever it lacks in nuance it makes up for in ease of playability.

What could have quickly become a folly on my part was redeemed by someone who took the time to develop their skills. I always hope that people will be excited to play their instruments after I've worked on them, so it was nice to be on the other side of that transaction.

I am regularly impressed by the skills of other technicians made evident through their work, and I'm fortunate to see work that is inspiring and informative from colleagues who are willing to share their experience. In this case, hearing David's explanation and asking a few good questions was helpful in developing a strategy for the clarinet bore graft that I just completed. Between the insight I got from talking to him and Mark Jacobi, that instrument went from a lost cause (in my hands), to a long shot, to a feasible job, to a successful and completed repair. It was exciting that while David was doing that work on my instrument, I was able to do a similar (but lets face it, much simpler) repair for my customer.

It's invigorating to develop and refine a new skill that can be useful to another musician. It's exciting, too, to be that musician and know that someone who has spent years honing their skills is putting them into practice on your instrument. I was grateful at having this opportunity to be reminded of those things.

Low A Oboe

I had this fun little guy in a few weeks ago. The owner said that, among other issues, the Low A mechanism wasn't properly regulated. How he realized that, I don't know, but it certainly wasn't from all the demanding Low A passages out there. Maybe he plays a lot of full range scales.

It was fun to work on, and the owner couldn't have been more pleasant. The Low A mechanism is pretty straightforward; it's activated by a right thumb touchpiece and is designed to also close the Low B and Bb keys, so you can go straight from C to A just by depressing the thumb. The only complication is that there are two regulation screws between the Low B and Low Bb keys. One is to adjust the regulation when playing low Bb, the other (visible in the center of the following photo) is to ensure that the Low B closes when playing Low A, which is tricky because of the flexibility of the very long mechanisms. It took a couple minutes to figure out, but now I'll be ready when the next one comes across my bench in 2038.

I hate that bench. Damn, we need a better consultation space.

Sleeving the Upper Joint of a Clarinet

Every now and then, an instrument comes along that makes you say "What?" and/or "Huh?" and/or "Seriously, what?" This clarinet quickly went from a request for a tune-up, to an overhaul, to a major bore repair. The story is that many years ago, the top of the instrument was smashed, cracked, and started to split apart. Two enormous cracks testified to that, as did two flush bands and a tenon ring installed by a previous technician. Actually, a flush band would have to be flush by definition, so really it had one flush band and one, uh, hose clamp? It was a very nice hose clamp, though.

Whoever did that repair clearly cared about their work, and was proud enough to have engraved their name on the tenon ring. I'd like to think that if he were doing this job today, with access to modern adhesives, materials, and know-how, he would have taken a different approach and done a really nice, attractive repair. But 40-50 years of being constricted by those bands really took a toll on the instrument. With nowhere to go as it swelled and contracted, the wood split and splintered into the bore. The original cracks, held together only with shellac, reopened and extended. By the time we got to this instrument, it was in sad shape.

The previous repair, with hose clamp, flush band (really nicely installed) and a tenon ring/cap.

After removing the hose clamp and washing the wood to remove old oils and shellac.

Inside the bore, looking down from the top of the joint.

Another vew, showing just how severe the damage was and how far the splinters protruded into the bor.

With the bore in that condition, the instrument was uplayable, even if it hadn't been leaking through the cracks. We weren't sure how to proceed,so we tried several methods to smooth it out. After removing both bands to relieve the constriction/tension, we tried humidifying the wood, then letting it rest, then pushed it over a fitted steel mandrel and left it there for days (the Votaw .585" mandrel happened to fit perfectly, which was a bad sign because the bore of this upper joint should have been .576"), then let it rest for even more time, but nothing moved. 

It seemed like a loss, but the owner has a strong attachment to this instrument. I had arrived at the limit of my experience, so we reached out to Mark Jacoby, a legendary clarinet specialist in Philadelphia. He was kind enough to give us some of time to evaluate the instrument and strategize. He tried a few things that helped somewhat, but we all agreed it wasn't enough. He let us hang around in the shop a while, though, and in passing mentioned the possibility of installing a sleeve in the joint. That would mean boring out the damaged section of wood and machining a plastic insert to replace it. After we departed (reluctantly, as Mark is a really great guy and a font of knowledge), that idea stuck in my head. I was drawn to it for a simple reason: I was about to send off my own english horn to David Teitelbaum in New York to have a sleeve installed in the upper joint, and was inspired by his incredible work to stretch my own skills. I knew I couldn't do such a job on an oboe or english horn (yet), but a clarinet seemed feasible. How serendipitous it was that I happened to have this instrument in the shop. When my english horn came back playing like new, there was no doubt I was going to attempt this job. Cue the A-Team theme (with NBC Television's OK)...

ABS stock for the insert is set up in the lathe and center-drilled.

The insert was drilled out to .500"with a regular drill bit. The finished bore dimension will be .576" at the top, and tapered down from there

After drilling the inside but before boring, the outside dimensions are turned. The outside of the sleeve had to be .875" in diameter to match the cutter that would bore out the damaged wood from the upper joint.

Sleeving the upper joint requires the original tenon to be removed, and the replacement tenon is integral with the sleeve. Here the groove is being cut to hold the tenon cork.

The (mostly) finished tenon.

Boring out the insert to be closer to the final dimensions. I chose to do this before installing it, as my lathe isn't large enough securely hold the entire upper joint for boring.

Boring left a surprisingly smooth finish, but it will be reamed later to create the necessary (slight) taper.

Measuring the internal dimension of the insert. With that done, it was time to move to the instrument.

The original tenon was chucked up and cut off.

A .875" aircraft counterbore was used to bore out the upper joint. The cutter is centered by a pilot that passes through a fitted plastic guide inserted into the bore. The hose clamp (an actual hose clamp this time) is to prevent the joint from flexing and splitting along the existing cracks. Removing so much wood significantly thins out and weakens the wall of the joint, thus the need for reinforcement.

One of the cutter teeth visible through the Bb trill tone hole. About 2.5 inches had to be removed, to just above the Throat A tone hole.

Two views of the upper joint after boring is complete. The counterbore left a very nice finish. The two spots visible in the second picture are the holes for the register key posts.

With the insert in place. The insert was left long to allow room for error. Not that I make those.

Cutting off the excess.

The upper joint and insert just before assembly.

The insert was epoxied in place and set on the lathe to cure. The lathe here is simply serving as a work fixture - its rigidity prevents anything from moving as the epoxy sets.

With the epoxy set and cleaned up, the seam between the body and tenon is nearly invisible.

Looking down the now straight and even bore

All that remains now is to redrill the three tone holes covered up by the sleeve, ream the insert (with Mark's help, as I don't have the necessary reamers), band the cracks with carbon fiber to prevent them from extending any further, then oil the joint and proceed with a normal overhaul. In just a few weeks this instrument will be up and running like nothing ever happened.

Incidentally, if I actually had played the A-Team Theme song while I worked on this, it would have played 184.6 times before I was done. I really took my time to avoid any potential catastrophes. Meanwhile, the actual A-Team could have retrofitted 500 vans for non-lethal battle and still had ample time left over for Mr. T to pity several fools.

PMEA Presentation

For those teachers that attended my presentation at the PMEA inservice today, here are the links to the documents from the presentation, with full-color pictures and what-not:

Powerpoint Presentation (well, Google Slides, so no need to sign in or download anything): https://docs.google.com/presentation/d/1Jw3k4L7Hfkm3F5BH3BZTYdDhJN7Oada3a4wvgcMt6A0/edit?usp=sharing

Tool list: https://docs.google.com/document/d/1YUJUk9zB0f4NI08KvO0T7QLd3hNIv-ez6ekQ2ku6QVQ/edit?usp=sharing

Please contact me if you have any questions, and thanks for coming!

Saxhorn Dent Removal

A regular customer who plays in a Civil War band brought in this over-the-shoulder tenor saxhorn that had taken a bad hit on the upper bow. The resulting dent was so deep that it almost closed off the tube, rendering the instrument unplayable.

It would've been a neat instrument to work on even without the dent work. We dated it to sometime in the later 1800's, although it fits as a Civil War era instrument as over-the-shoulder horns were patented in 1838 and had become commonplace among brass bands in the 1860's. We call them saxhorns, as the musicians did at that time, although strictly speaking saxhorns were patented by Adolphe Sax in 1845 and of a very slightly different design. True saxhorns were more commonly upright instruments, though marching musicians preferred these over-the-shoulder instruments because they were easier to carry. This one uses Berlin valves, an early piston valve design from the 1830's that also fits with the period, though apparently over-the-shoulder instruments more often used rotary valves.

The other notable thing about this instrument that will forever burned into my memory is that the brass was t-h-i-c-k. Whatever caused that dent must have fallen out of an airplane or the space station to have left that kind of damage. Anyhow here's a little photo essay of the process.

The dent was in the upper bow, indicated by the white line, which had to be pulled off. As a bonus, the leadpipe coming out of the 1st valve casing also came off in the process. Great!

The tube had to be annealed to soften it, then the first part of the dent removal process was to raise the dent enough that a ball would be able to pass through it on the inside. That meant soldering a brass plug into the center of the dent, chucking the plug into a vise, and pulling on it until the solder failed and the plug let go. That process was repeated three times to get to this picture. Prior to that the dent was so deep that there was a danger of the brass folding over itself as the distortion was raised. This process mitigated that risk.

After working several graduated dent balls through the dent, the surface is smoothed out some but the area is still significantly distorted. The tube has to be repeatedly annealed to soften it, as the process of repeatedly hammering and reshaping the metal is constantly hardening the brass.

Getting closer! The last few balls needed to get the tube up to the right diameter went through very slowly. Patience is key.

After buffing and mounting, here is the finished part. Hey, I got the leadpipe reinstalled, too!

One more before and after.

Jarde Oboe - Left F Modification

This was a great project I got to do recently - adding a left F lever to an older oboe that didn't have one. It used to be you could order all or most of these parts from Fox and build the mechanism yourself, but they've recently made it more difficult to do that so I started from scratch. I got a chance to break in the new (old) lathe by trying some single-point threading and making hinge tubing from a solid rod, using a technique I read about from another tech. Plus I inhaled a lot of nickel dust cutting the keys out of a solid bar.

When making the posts, the rough shape was first turned on the lathe.

The threads on the posts were cut on the lathe to match the existing posts already on the instrument. The posts were going into new holes, so it would have been possible to tap them with any thread, but for consistency's sake I kept the same measurements as all the existing posts.

The final shape was filed by hand using a bench motor.

New post holes were drilled on a press, then the holes were tapped and the posts were checked for fit. The "caps" on these posts were left on to provide something to grab on to while they were repeatedly removed and reinstalled.

This swell post-drilling jig (made by Matt Slauson up in New York-thanks Matt!) keeps drill bits aligned to the center line of the posts while drilling holes for the screws.

Evidently I forgot that I had a camera for awhile, so there's a few scenes missing between this picture and the last one. But you can see the hinge tube mounted between the posts and through the key. A new screw goes through the posts and hinge tube. The lower part of the left F touchpiece is shaped and waiting to be brazed to the upper part

A view looking down toward the new post for the rocker part of the mechanism. Originally the post in the center of this picture was threaded to hold a screw, now it's been bored out so that a longer screw can pass through and thread into the far post.

A side view of the touchpiece, now with the upper part brazed to the lower part. The other keys have also been reinstalled.

The rocker mechanism engages with a new tab brazed onto the original F key. A long screw passes through the D trill touchpiece (on the right) and continues through the rocker and into the new post on the left.

The rocker passes under the long rod for the Eb/Low B/Low Bb keys

A general view of the new touchpiece and rocker, all finished and ready to ship!