Buffet English Horn Bonus Post - Crack Pinning with the JDB Method

Over the course of my first week with this instrument, I was playing it a lot in a show. After a few days I noticed a marked decline in its response, and an inability to hold a vacuum on the upper joint. Turns out the culprit was...

A crack around the lower octave pip. I was of course disappointed, but not too surprised by it. The instrument has sat unused for a long time and was all of a sudden getting played daily. Furthermore, this area is especially prone to cracking because 1) the top of any wooden instrument is where you'll most likely find cracks due to the huge amount of warm air and moisture that passes through the top of the bore, 2) the octave pip is a large piece of metal that doesn't expand and contract at the same rate as the wood, and 3) the hole for the octave pip is pretty large compared to the total circumference of the joint, so it creates a relatively large weak spot.

I discovered it only a few hours before a show, so I quickly filled the crack to stop it from leaking that night, then repaired it properly the next day. You can see in the first picture that I had to scrape away the temporary filler to clean it for the actual repair.

The crack was over an inch long, and cracks of that size are often repaired through pinning. The traditional method of pinning involves drilling holes across the crack at an angle, then inserting a threaded steel rod. The pin prevents the crack from being able to expand and contract, so ideally it will be stabilized and unable to grow. The crack is then filled, usually with a mix of superglue and wood dust. That's how I've done pinning in the past, and how a lot of people still do. It's still a very popular and perfectly viable method. However this time I wanted to try a new technique I recently read about, one that's been popularized by Julian Dale Barton, a technician from the Washington DC area. In his "JDB Method," an unthreaded carbon fiber rod is substituted for the steel rod. The procedure is quicker, the cleanup is a little easier, and since the rod doesn't actually get "screwed" in, there's less wood displaced. Otherwise, the process is largely similar.

You start by drilling the holes. They must be drilled at an angle to the crack, as that's what prevents the wood from being able to move once the rod is installed. I did two holes above the pip hole and two below. As you can see, it's a pretty invasive process.

Next the correct size carbon rod is dry fitted, and notched so that it can be broken off at the correct length after insertion.

The rods are installed and glued in place.

Then the ends are filed and smoothed so they don't protrude. The crack is also filled and dressed to hide it and add a little more stability.

After sanding the surrounding area a little bit and applying oil, this is how I left it for a few days while I was finishing up my recent gigs. The functional part of the repair is done at this point, and all that remains is cosmetic work.

A few days later I was able to clean things up and hide the pins. I started by grinding down the ends.

Then filled them with wood dust and glue.

Next is where the real art and finesse comes in to a repair like this. You want to blend things in so they're invisible, or at least redirect the eye so that no one would ever look for evidence of a repair. The result is below. If you look closely enough, you can see evidence of one of the pins, but otherwise they blended in almost perfectly. 

Having all the keys on helps divert the eye, too, because there's so much stuff up there that a lot of the wood is covered up by nice eye-catching silver. Thanks silver!

I'm very grateful to Julian Dale Barton for sharing this technique, which I'll be using on any cracks I have to repair in the future. If you want to see more of his work you can see his Facebook page here.

Next project - replacing the octave levers and doing away with that silly automatic mechanism.

Buffet English Horn Day 20 - 3/4/14

Today was the day - I had a deadline of 6pm to finish the english horn and play it in a rehearsal. Having mostly leveled the lower joint pads yesterday, I spent the first part of today rechecking all those pads and making final adjustments. Then all the regulation screws went back in and I started the regulation process. Along with that I had to adjust spring tensions, trim and replace corks to adjust key heights, and secure a few posts that kept coming loose. I also got to reinstall the post from that cracked area around the C# tone hole. I tried to reinstall it once before, but the post hole had a good bit of superglue in the threads which meant that the hole was smaller than it had been. When I tried to force the post in to place, it started to crack the wood again. So this time I took a post I no longer needed - in this case the lower post from the C#/Eb lever that I ended up replacing - and cut some slots in the threads so it would work like a tap by cutting away the excess glue and restoring the threads. I just used a Dremel tool with a knife-edge wheel to cut the slots.

After recutting those threads, the post went in nicely, with a little epoxy added to hold it in place. The area that was cracked is pretty much indistiguishable at this point. In the second picture you can just see where one of the cracks started just below the post and extended about an inch to the right. I'm really happy with how it turned out. Thanks to fellow tech Julian Dale Barton for sharing his technique for surface crack repairs.

Finally, with the pads all leveled, the keys fitted and installed, and the preliminary regulations set, it was time to get out my new bocal (a Fox 2XL - a gift to myself for finishing the project) and play this english horn for the first time in who knows how long. And...

It didn't play. Turns out I forgot to check the bridge regulations when I put it together. So I took care of that, took another breath and...

It played! Having never heard it before, I didn't know what to expect, but it actually sounded like an english horn! The tone is somewhat dark. It doesn't have the color that some players might desire, but I prefer a darker sound so this is right up my alley. Of course once I got it playing I realized that the wacky octave mechanism needed more adjustment, and there were a bunch of other regulations that needed tweaking, and the Low C# is really fuzzy (still working on that one), but it works! I was able to play it at rehearsal, and it felt good the entire time.

Of course that's not the end of the story. Over the coming days and weeks, things will settle in and I'll need to continue making adjustments. With an instrument that's sat idle for so long - at least 10 years and probably much longer - there's also the possibility that it may crack, although I suspect that if it was ever going to crack, it would have done so by now. Aside from that surface crack that came from being whacked, it clearly hasn't.

In the next few months I plan to make new octave levers so that I can do away with the automatic octave mechanism. I'd also like to make a left hand F key. I kept reaching for that this evening at rehearsal and finding nothing there. There's also some voicing that needs to be done to really make it sing, but for now it works perfectly well, and more importantly I was able to have it ready on time.

As I continue to tinker with it I'll try to update with more posts, but this part of the saga is over. In 20 days I was able to take a completely non-functional instrument that spent years sitting under a workbench and rehabilitate it into a beautiful instrument that I can take pride in and feel a deep connection to. Every time I take it out to play I can look back on this whole restoration process and know that I'm holding the product of my own sweat and blood. But mostly blood. A surprising amount of blood.

But in reality it wasn't a project I completed alone. I bounced lot of ideas off my coworker, Mike, and he bounced them back when they sucked. I had help from Tim the machinist at Peterson Machine who made the tone hole facers, my coworkers Cindy and Frank who ordered the bocal and case, and a network of incredibly helpful and knowledgeable repair techs who are eager to share what they know. And there's also my old college classmate Debbie, who sold me the instrument (thanks Debbie!) Most importantly, though, I have Steph, my understanding wife who allowed me to neglect her for 20 days while I obsessed over this project from a desk 10 feet away. Seriously, she's pretty incredible, guys.

If you've read any of this, thanks for taking the time! Here's a final before and after.

Before

After, alongside my oboe in a new double case (the case was also a present to myself)

On to the next project!

Buffet English Horn Day 19 - 3/3/14

Re re facing lower joint tone holes, gluing lower joint pads, seating, key corks, broken springs, tapping and gluing post into cracked area

Today is Monday March 3, my target completion date for this instrument. It's not a date I chose arbitrarily. I have a rehearsal for a show on my schedule at 6:00 this evening, and I need to play english horn. I was stressing about it overnight, because I don't see how I'll be able to pad the lower joint and make all the necessary adjustments by that time in order to be able to play it. The weather gods have been good to me, though, and the school that's putting on the show is closed today because of snow, which means tonight's rehearsal is postponed to Thursday. Add to that the fact that work opened late, and I had all morning to work on the lower joint. I corked all the keys, re faced the tone holes again using what I'd learned from the upper joint (they turned out great!) and faced and glued all the pads.

You may recall that cork pads, because they have almost no compression,need a perfectly flat and smooth tone hole surface to interact with. That also means that the pads themselves need to be flat. They come pretty flat from the manufacturer, but I always reface them by sanding with 600 grit sandpaper on a bench anvil in a figure 8 pattern. That ensures a flat and defect-free surface. It also allows you to thin out a pad if it's too thick for a particular key.

Since cork pads come as disks with no relief on the back, it's necessary to bevel the back of the pad. That way you can shift it around in the pad during leveling, and the glue behind it will have somewhere to go. I bevel pads by simply running a razor blade around the back. 

Next the pads get glued in to their key cups. The pads should fit neatly in the key cups so they can't shift from side to side, but they shouldn't be tight at all. A pad that's too tight will be difficult to move during leveling, making it nearly impossible to make the minute adjustments necessary to get a perfect level. If a pad is too tight, I glue the back of it to a screw or nail with a flat top, put that in my bench motor, and spin it while sanding a little bit off the sides. They get glued in with George's Glue (pictured), which isn't the only adhesive you can use, but it seems to be the

preferred choice of most techs for installing cork pads because it's very sticky and thick. A thick glue is better for allowing very small adjustments, whereas a runny glue would be more prone to shift around after you've leveled the pad. I check pad level with a pad slick that's .0005" in thickness, so the pads have to be level with the tone hole to within that tolerance. With the pads and corks on, it was time to go to work, so I had to stop for a while so I could get paid to fix other people's instruments. It's a pretty great gig, right?

When I resumed later in the day, I started by replacing some broken springs, installing keys, making final adjustments to key fitting, and leveling pads. The leveling actually went pretty smoothly, owing to all the prep work I'd done on the pads and tone holes. By the time I had all the pads in, though, I was pretty wiped out and done for the day, so I called it quits. The lower joint had a few more issues than the upper joint did, especially with those broken springs, so I kept getting sidetracked by little problems. Tomorrow I'll need to take some time out of work and hopefully finish up. And by "hopefully finish up" I mean that I ABSOLUTELY HAVE TO FINISH THIS THING TOMORROW. There's another rehearsal for the show scheduled for tomorrow night at 6:00, so come hell or high water this english horn will be able to produce some kind of sound within in the next 24 hours.

Buffet English Horn Day 18 - 3/2/14

Today was supposed to be devoted to padding the lower joint, but I tried to do so much on the upper joint yesterday - facing tone holes, getting that last 1% of key fitting, trying to level pads to the highest possible tolerances, etc. - that I needed to spend today finishing the upper joint. I did finish padding, though, and after that spent a couple hours fussing with regulation and adjustment screws. Regulating an oboe or english horn can seem like an endless back and forth, especially when working with cork pads that are extremely unforgiving. When two cork pads are regulated to each other (or in the case of the the G key on an english horn, three pads), they will either close at exactly the same time, or be completely off. There's no middle ground like there can be with skin pads, so I spent a lot of time finding just the right spot on each regulation screw. Of course, as things settle in over the next few days, those regulations will have to be further adjusted. It's like chasing your own tail. Or at least that's what I imagine it's like. I've never chased my tail, and I'm beginning to suspect I don't even have one.

I don't even want to get in to this convoluted mechanism.

The difficulty of regulating was compounded by the ridiculous automatic octave mechanism on this instrument. It opens the correct octave key (upper or lower) regardless of which octave lever you press, which is surely a nice feature for someone who doesn't play oboe or english horn that much, like a doubler. But if you know how to use both levers interchangeably, there's really no reason to have such a complex mechanism. Unfortunately there's no way to disengage the it, so it has to be set up, which took a lot of time to get right. Incidentally, the upper octave key is regulated to the G key, so I just realized that what I typed above about the G key closing 3 different keys is wrong. It has to close four keys. There's so much spring tension in those four keys that the G key feels extremely heavy, no matter how lightly the springs are set. My plan in the near future is to make a new octave mechanism that will work manually, just like it does on any other double reed instrument.

In the end, all that fussing and fidgeting seems to have paid off. The upper joint is padded and regulated, and draws less than one on the magnehelic machine with light finger pressure. If that statement means nothing to you, don't worry about it. Here's a picture!

Buffet English Horn Day 17 - 3/1/14

First day of padding! Though not before taking care of a few other things first.

Although I had already faced the upper joint tone holes, I decided to go back and check everything again with a discriminating eye. And it's a good thing I did, because a lot of them still had chips or uneven rims, and needed more attention. The order of operations I ended up using that gave me the results you see below is this:
1) Dip the head of a pin in medium-thin superglue, then run a bead around the rim of the tone hole. Allow it to set a few minutes
2) Dress the tone hole's outside taper with my fancy new facers covered with 220 grit sandpaper
3) Establish a flat surface on the top of the tone hole with the flat side of the facer and 600 grit sandpaper (the 600 grit loads up quickly so it has to be replaced frequently)
4) Once a smooth, flat surface is established (ideally not too wide), chamfer the inside of the tone hole with a pad seat reamer (pictured, available from Ferree's Tools)
5) Check everything under magnification. Sometimes the pad seat reamer catches on the tone hole rim and chips it. Simply fill any chips with glue and repeat above steps.
6) Continue checking obsessively until your eyes hurt
The result is a smooth, even, defect-free rim like you see below.

With the tone holes faced, I took a detour to a small project on the upper joint - wrapping the upper tenon rail in silk. Wooden tenons - especially middle joint tenons - tend to be come wobbly over time. A lot of players seem to think that this can be remedied by replacing the tenon cork, but the tenon cork really only does two things. It provides friction to prevent the joints from falling apart (longitudinal movement), and it acts as a gasket to create an airtight seal between the joints. A tenon cork can't, however, eliminate wobble (lateral movement). The middle tenon on a woodwind instrument is usually very short compared to the length of the upper and lower joints, so those joints exert a huge amount of leverage on that little tenon. Cork is just too soft to be able to withstand those stresses. The rails, however, are strong enough to hold up against that lateral force and prevent wobbling. Rails can either be wood (or plastic, if that's what the instrument is made of) or they can be shrouded with a metal sleeve, in which case the socket will have a matching metal liner.

Metal rails have a two-fold advantage. First, they don't expand or contract with changes in humidity and temperature, so if an instrument has metal rails and a metal-lined socket the tolerances between them can be very close to ensure a snug fit. Wood rails and sockets swell and contract a lot more, so they can't be fit as closely lest they become stuck. The second benefit of metal rails is that they don't wear as much as wood. Even a wood as tough as grenadilla will eventually wear down under the lateral stresses exerted on the middle tenon. That's why older clarinets and oboes almost always have a wobbly middle tenon, and why this english horn did, too. 

Whoever engineered this instrument clearly understood this, because it has a metal liner in the middle socket and the lower rail of the middle tenon has a metal sleeve. Unfortunately, the upper rail takes the brunt of those lateral forces, so it had worn down and there was a noticeable wobble. There are several ways to deal with this problem. Some techs wrap the rails in cork, but I don't like that because it doesn't seem to last. The ideal fix is to machine a new rail out of plastic, but for that you need a beefier lathe than I have, because you also have to cut the lower rail off the tenon in order to slip the upper rail on. I therefore went with the third option, which is to wrap the rail in silk. Silk is the preffered material for this process because it doesn't stretch like cotton (which ensures you get an even layer all the way around the rail). It also doesn't compress, so it can hold up against that lateral movement. Incidentally, the fact that silk doesn't compress is the reason a stuck silk swab can't be extracted by pulling harder on it.

The process of installing the silk wrap is actually pretty simple. You cut a strip of silk, making sure to follow the weft of the fabric. Then you tack it to the rail with a dab of super glue, and slowly wrap it around while following with thin super glue. The whole strip should be saturated with glue when you're done. This keeps it in place on the tenon and adds a little bit of reinforcement. Once it's dry, you can go around with a razor blade and cut off any excess. The silk will be stiff enough to cut cleanly.

After it's in place, you can file or sand the wrap until it fits snugly in the socket. This one required minimal fitting, and now it fits perfectly in the socket with no wobble. 

After that, I put the springs back on the upper joint, made final adjustments to key fitting, and started fitting and installing pads on the upper joint keys. More on that with tomorrow's post, which will focus on the same process but for the lower joint (this post is just getting a little long). But here are all the upper joint pads glued into their cups

And then on the 17th day, I padded. Here are the first two keys, the G and Bb, on the instrument at the start of that process. I anticipate there are between 10 and 15 hours of padding, regulation, key fitting, and other adjustments between me and a functional english horn.

Buffet English Horn Day 16 - 2/28/14

Busy day in the shop today, so all I really had time to do on the english horn was plate that new post and the Eb lever that I cracked and repaired last week. For plating we use a small Caswell Plug N'Plate. It's a pretty simple rig. You hook the cathode up to your part, and the anode in this case is a little chunk of silver on the end of a wand. The plating solution is a liquid with metal salts dissolved in it to make it conductive sot that electricity can pass between the cathode and anode, completing the circuit. As electricity flows, the silver anode oxidizes very slowly, depositing positively charged silver ions into the solution, which are then attracted to the negatively charged cathode, where they bond to the surface.
Normally to use the Plug N'Plate you would wrap the anode in a cloth that you then soak in the plating solution, then brush the cloth on the part you want to plate, completing the circuit. But these parts were small enough that I could just immerse them in the plating solution along with the silver anode.

It took a few tries to get things right. The surface to plated has to be very smooth and perfectly clean for the process to work. Any grease or foreign matter on the surface will prevent the silver from adhering. I had to degrease several times before the silver actually took hold.

When the part comes out of the plating solution, it's completely black. If you've done things right, though, you can wipe off the black crud and reveal the silver plating underneath. Here's how the post turned out. 

Here's a before pic of the raw brass finish for reference.

And here's the Eb lever from last week.

And a before pic. The difference isn't as noticeable in these pictures, but in person the raw brass really stuck out like a sore thumb.