Buffet English Horn Day 15 - 2/27/14

I was able to stay late at work tonight to fix the error I made yesterday in drilling the pilot hole in my new post. And by "fix the error" I mean "make a new post. I though it would go more quickly this time, but really it didn't. That's ok though, because (spoiler alert) the new post turned out super great. 

I had to start by resharpening the tool bit on my lathe, which was already dull the other day when I was working on the first post, and by now was in really bad shape. I'm still learning to sharpen bits, so it took me awhile, but after a few false starts I got the bit nice and sharp. 

I just turned the threaded section on the lathe this time, then did all the other shaping by hand with a file in the bench motor. Last time, I cut the post off the excess brass rod before checking the fit and position in the body of the instrument. That resulted in a lot of marring on the face of the post from where I had to grab it with pliers to thread it in. So this time, I checked the fit and position before cutting off the excess. That way I could just grab the excess rod with a pair of pliers and scratch that up without touching the post. I also drilled the pilot hole and spring hole before removing the excess this time, and I drilled the holes much more carefully and slowly. Here's the hole thing after drilling, right before I cut off the excess.

Then I used my tuba valve stem from the other day to hold the post in the bench motor while I further shaped it.

After shaping and sanding, I checked the fit one more time before countersinking the back of the post to receive the pivot screw head, and facing the front to mate with the key.

Here it is after facing, with the key up against the now flat face of the post. It fit perfectly!

With the key removed, you can see the flat face. I don't have a mill, so I had to get a little creative to figure out how to cut a smooth, straight face. I used a hinge tube shortener and it worked very well.

Here's a final shot with the original post, the new post after buffing (it's ready for plating!) and the piece of brass rod I used to make it.

After that, I was on to wood working on the lower joint. Careful checking revealed that I needed to be a little more fastidious than I was with the upper joint tone holes last night, so I really took my time to establish a flat on each tone hole, face the outside with my new facers, then chamfer the inside with a set of pad seat reamers. I checked each one multiple times with a light in the bore, a 10x eye loupe, and a faced brass rod for reference, and I'm happy with how things came out. If I studied the results correctly, then padding should be relatively smooth this weekend.

Tone hole facing was the first half of wood working I had to do on the lower joint, and the second half was repairing that nasty crack near the C# tone hole where a post had jammed. I started by filling the gaps and pressing the wood back into its correct shape as much as possible. That was followed by sanding the surface smooth and adding more glue to fill the remaining cracks. Alternating those steps a few times gave me a nice smooth surface with a minimally visible repair. I suspect that after the wood is oiled, things will blend a lot more smoothly.

Here it is in progress.

And after sanding and smoothing.

And for reference, here's what it looked like before.

Now the lower joint is in the immersion oiling tube, the upper joint is drip drying, and tomorrow I should be able to fix the split in the upper D ring and plate the keys that need it. I'm (hopefully) only a few days from having a functional english horn!

Buffet English Horn Day 14 - 2/26/14

Today I started facing tone holes. I found the perfect glue to use for sealing the tone hole rims - a superglue that's not too thick or thin, so that I can wick a thin bead all the way around the rim. The facers seem to be working well, too. I got all the tone holes on the lower joint leveled and then dropped that joint in the immersion oiler. Tomorrow I'll take care of the lower joint tone holes and deal with that crack near the C# hole.

I also installed the new post I made and got to check its fit.

I don't know why that picture looks so washed out. Oh well. The post fit well and was the right height, so that was great. Unfortunately, while I was drilling the pilot hole for the pivot screw, the drill bit wandered a little bit, and I ended up with a hole that wasn't centered. So it looks like I'll have to start over with a new new post. This time the job should go much more quickly since I've already done it once.

Buffet English Horn Day 13 - 2/25/14

I got my tone hole facers today!

The machine shop I used was Peterson Machine in Chester Springs, PA. The machinist there, Tim, was great to work with and his work turned out very nicely. Not only that, but turnaround time was quick and he kept me in the loop. He said he measured the angles of all the tone holes and they weren't all the same, so he sort of averaged them out to make the facers. I'll be trying them out tomorrow and hopefully they match!

Buffet English Horn Day 12 - 2/24/14

This morning I threaded and cut off the post I started yesterday, then made a threaded jig to hold it out of an old tuba valve stem. Now, once I have the pivot screw hole drilled, I can polish and buff the whole thing without scouring away my fingerprints!

Later in the day I had a chance to talk to the machinist working on my tone hole facers, and he said they should be done tomorrow. Buoyed by that good news, I spent the evening corking keys.

Buffet English Horn Day 11 - 2/23/14

Today's job was making a new post. One of the posts on the lower joint looks like it was cut or ground down at some point, so it doesn't contact its key at a nice square angle. Unfortunately, I don't have the body of the english horn (it's still with the machinist making my tone hole facers), and I left the thread die I'd need at work. But that's okay, because I could still get some work done.

This is my lathe, a Unimat that I rebuilt last year. It's not perfect, but it runs pretty well and is perfect for working on small parts, especially something like this where I just need to use it to rough out the shape and then finish it with a file and sandpaper. It's not great at creating a nice smooth finish, although that probably has more to do with my meager abilities at machining and tool bit sharpening than it does with the machine's limitations. I am getting better though, and in the future when I can purchase a larger, more precise lathe it will provide an opportunity to continue developing those skills.

I used the lathe to turn the end of the brass rod down to the diameter needed for the post threads. Like I said, I don't have the die to actually cut the threads, but that'll be a quick process now that the rod is the correct diameter.

You can see above that I also used the lathe to rough out the shape of the post, but that put me at the limitation of my tool bit and skills, so from there I moved on to filing with bench motor.

Here it is, with the curves smoothed out and closer to the finished shape.

Finally, I roughed out the sphere at the top of the post, but left everything attached to the rod so that tomorrow I can grip it in the bench motor while I cut the threads. After that, it's just a matter of lining it up in the body, marking and drilling the screw hole, tapping the screw hole, and plating it.

Things always look rough after filing, but a little sanding and polishing left a very nice finish, which I can further smooth by buffing later.

Buffet English Horn Day 10 - 2/22/14

Not much to report today, as I spent a large part of the day traveling to and from the birthday party of a college friend's son. It was a great time, and while there I was able to finally pay for the english horn I've been working on for over a week (don't worry, I had the previous owner's permission to start working). She's another friend from college who also happened to be at the party, and it was nice to catch up a little bit and talk about the project. I'm grateful that she was willing to part with it, so that I could have the opportunity to give it a new life. 

Buffet English Horn Day 9 - 2/21/14

This is my immersion oiling tube, filled with oil. There are many like it, but this one is mine. 

I mean, I guess there aren't many like it, but there are surely a few out there.

What's an immersion oiling tube for, one might ask? It's for oiling the wood of an instrument when it's fully disassembled. The tube lets you dunk the instrument in and get it fully covered with oil, which can then be absorbed into the wood. Once I level and dress the tone holes on the english horn, I'll oil it and let it sit a few more days before doing final key fitting and padding. That's still a few days away, though.

There's a good deal of debate about the process of oiling wooden instruments, including questions about whether it's even necessary, and a lot of differing opinions on what kind of oil is best. To start from the beginning, though, there are reasons for oiling, whether you think it should be done weekly or only once in the life of an instrument. Wood starts as a living thing that either absorbs water or expels it depending on atmospheric conditions. Once the wood is felled, processed, and turned into a musical instrument, it still interacts with the humidity in the air. A piece of wood that's allowed to remain in a very humid environment soaks up a lot of moisture and can develop things like rot, mold, or fungus. On the other hand a piece of wood left in a dry environment for years will eventually give off most of its moisture and dry out. Dry wood is more brittle than humidified wood, so it's more prone to chipping and cracking. A very dry instrument that's suddenly subjected to a rush of warm, moist air from a player's lungs will start to absorb that moisture quickly, causing the bore to rapidly expand while the outside wall is still dry. It isn't hard to imagine how a crack can develop in that situation. By the same token, if a piece of wood suddenly absorbs a lot of moisture from the air, there's no way of telling what other things might come with it, like bacteria, mold, or any number of other kinds of funk. Therefore it's in the player's best interested to 

Musical instruments are regularly subjected to pretty severe changes in humidity, not only from the infusion of moist air from the act of playing, but also from the different locations a musician might use their instrument and the seasonal changes in humidity that happen in many parts of the world. Oiling helps slow the wood's reaction to these rapid changes, which prevents it from expanding or contracting too quickly. The oil fills voids in the wood, coats the individual cells, and creates a semi-permeable barrier for moisture to pass through, which it does at a gradual pace. This has the double advantage of preventing rapid expansion or contraction of the bore which can cause cracks, and minimizing the absorption of water vapor that may carry bacteria, mold, or some other kind of "funk." 

Of course in order for the oil to do its job, the wood needs time to absorb it, which can take hours or days depending on how "thirsty" the wood is. Wiping the bore of an instrument with oil and immediately cleaning it out will probably have a negligible effect, as almost zero oil gets absorbed. In fact, the only effect may be that a microscopic layer or oil gets left behind in the bore, which will prevent it from absorbing any moisture for a few days. That's why an instrument should always sit for a few days after a full immersion oiling, and maybe a day or so after oiling the just bore.

So which type of oil is best? The short answer is that I don't know. Most people agree that on grenadilla instruments, hardening oils like linseed or tung oil should be avoided. These oils gradually dry out and leave behind a coating that creates a vapor lock, preventing any moisture from getting to the pores of the wood. As a result, the wood can't respond to changes in humidity. (Ok, it doesn't completely prevent moisture from getting through, but the Berlin Wall didn't completely stop people from crossing the border either. That doesn't mean it didn't slow things down quite a bit.)  Another type of oil most people like to avoid are the commercially available bore oils available from some music retailers. These are usually petroleum based oils, particularly mineral oil. Mineral oil doesn't seem to be terrible for the wood, although it is toxic if ingested. From what I understand the main downside is that mineral oil doesn't contain the right fatty acids to be able to polymerize, so it doesn't stick around very long and doesn't really nourish the wood.

That leaves fruit/vegetable and nut oils. Fruit and vegetable oils are practically non-hardening, especially in the small amounts that would be distributed through the wood of an instrument, so that's a strong point in their favor. They can go rancid over time, but that assumes a standing amount of oil over a long period, so the risk of the oil in an instrument spoiling is minimal, and can be further reduced by adding antioxidants to the oil.

But even having narrowed down our list to these oils, there are still a myriad of options, and very little agreement on what is best. Olive oil and almond oil are both popular, but have their drawbacks. Olive oil can contain a lot of chlorophyll, which of course reacts with sunlight, and in this case can cause the oil to oxidize and go rancid. This can be minimized by using a golden colored extra virgin olive oil, which comes from riper olives that contain less chlorophyll. That still doesn't eliminate the possibility of oxidation, though. Almond oil, on the other hand, is difficult to find in a pure form because of the way it's extracted and processed. Those factors and other concerns mean that even these two popular oils have many detractors. I can't tell which is best, though I'd note two of the most popular products: Bore Doctor from Doctor's Products is thoroughly researched and developed by a chemist, Dr. Omar Henderson, and he is active in promoting the science behind his products, including its antioxidant and disinfecting properties. Naylor's Bore Oil is also a popular formulation, developed by Larry Naylor, a prominent veteran instrument repair technician. Both have strong following among repair techs. The formula I've personally started using in my immersion tube is one shared by Jeff Dening, and well-respected technician now working in Baltimore, and includes a couple different vegetable oils along with an anti-oxidant. In a year, though, I may be using something different, and a year after that something different again. I haven't firmly planted my flag in any camp yet.

Even after you can choose an oil, there's still the matter of deciding how to apply it and when. I oil an instrument if I'm overhauling it, after I've cleaned it and allowed it to humidify a little bit. Using the tube, I immerse it in oil to thoroughly coat every surface, then allow it a few days to absorb what remains on the surface. If it looks dry after that I'll oil it again. I don't go crazy with bore oiling as a regular maintenance practice, though. I do the immersion oiling after cleaning based on the fact that I've just washed the instrument a sucked a lot of oil out of it. The immersion process replenishes what I've taken out. Bore oiling is aimed more at nourishing the wood and hydrating it to prevent cracks. There's probably something to the idea that nourishing the wood with oil will prevent the wood fibers from breaking down over years of use, but the idea that oiling prevents cracking on an instrument that gets regular use is less convincing. If you haven't played an instrument in weeks, months, or years, and are planning to pick it up again, an oiling would probably be beneficial. The same if you're traveling with it to a place with a different climate. But if you're playing in the same locale on a regular basis, chances are your instrument isn't suddenly going to suck up a huge amount of moisture and split open one day when you pick it up to play.

If you are going to oil an instrument's bore regularly, it should be when the bore is clean and dry, and when it will have enough time to absorb the oil before you play it again.

I still have a lot to learn about oiling, but there is a wealth of information out there for those of us who don't have the wherewithal to do our own research or analysis. A few I've found helpful are:
http://www.shwoodwind.co.uk/HandyHints/oilingbore.htm
http://members.iinet.net.au/~nickl/wood.html
http://www.naylors-woodwind-repair.com/Publications/life-everlasting-for-a-good-clarinet
http://www.naylors-woodwind-repair.com/Publications/deterioration-of-grenadilla-instruments
http://test.woodwind.org/clarinet/BBoard/read.html?f=1&i=45168&t=45154
http://test.woodwind.org/clarinet/BBoard/read.html?f=1&i=92507&t=92393
Both threads from the Clarinet BBoard contain a lot of information from Dr. Omar Henderson

Buffet English Horn Day 8 - 2/20/14

Today's big accomplishments were a) finding a machinist who would return my phone calls and b) meeting with said machinist. He agreed to make me some pad seat facing tools that will exactly fit the angle of the tone holes on this instrument. With any luck he might even be able to finish them by tomorrow (Friday) so that I can start leveling and facing tone holes this weekend.
That's really all I have to report for today, but since you were kind enough to stop by, here's a picture of a wolf barking at a bear.

Buffet English Horn Day 7 - 2/19/14

Two days ago I wrote about doing some work on the right hand Eb lever after its tube split during swedging. That lever fits between the two parts of the C# lever on an assembly, and it turns out my work with that assembly was not done. Today was focused on making a replacement for a stripped shaft lock screw on the lower C# lever. In this picture, the red circle indicates the hole where that screw should go.

The shaft lock screws hold the lower C# lever to the steel hinge rod that runs through this whole assembly. On the other end, the C# touchpiece is permanently attached to the rod with a spline. The Eb lever between them, however, floats freely on the rod and isn't attached to anything. That enables the player to press on the touchpiece and cause the lower C# lever to move, while the Eb lever can remain stationary. This is all necessitated by the fingering system for the english horn and the location on the instrument of the Eb key (which would be directly below the assembly in this picture) and the C# key (which would be immediately to the left of the lower C# lever). The reason the lower C# lever has screws holding it on (instead of being permanently attached like the C# touchpiece) is so that the lower C# lever and Eb lever can be removed for cleaning, oiling, or other servicing.

A similar mechanism exists on flutes to enable the instrument to play Bb and F#. However on most flutes the keys are secured to the rod with tapered pins that can be knocked out. Most oboe and english horn manufacturers use tiny screws instead. The upside to this is that they're a lot easier to remove without marring the key. The downside is that a tiny screw is a lot harder to replace than a tapered knock pin. That being said, here's the process I used:

The first thing was to clean up the threads on the inside of the hole with a tap. That's a watchmaker's tap going through the key. You can't see its threads in this picture because they're so small. Sorry about that.

With that being done, the first step in making the screw was to turn a piece of drill rod down to the correct diameter, in this case .045 inches, which is measured with a micrometer.

Once the rod was turned down the correct diameter, it was time to thread it. The plate in this picture has dies for making several different sizes of screws, and you can see the newly threaded rod coming through the fifth slot. This is a delicate step, because the rod is so narrow and fragile. As the die cuts metal away from the rod to make threads, it can snag and break the rod. That happened to me twice, and fortunately both times I was able to extract the broken part of the rod from the die plate.

Once the rod was fully threaded I cut off the excess and smoothed out the head of the screw, then cut a slot with a jeweler's saw. This was most easily done with the screw threaded into the correct sized hole on the die plate.

  
Here's what the finished screw looked like. I didn't make the penny. That's just to show how absurdly tiny the screw is.

After that, it was just a matter of installing the screw in the hole, which was a little harder than expected because I used a pretty cheap tap and die set and the hole didn't exactly match. But by threading the screw in nice and slow like, it all got trued up and now everything fits together quite nicely.

And that's how I made a shaft lock screw. It was terrifying!

Buffet English Horn Day 6 - 2/18/14

Today I was stuck at home waiting for a guy to come fix our washing machine. With all my tools at the shop, there wasn't much I could do, which is a shame, because I had a buttload of free time. However, between making oboe reeds and domestic stuff, I did find time to polish the keys. I'm really amazed at the condition of the plating. There are five or six keys with any noticeable plating loss, and on the others the plating looks really great.

Here's a pic of the keys, post-polishing!

Buffet English Horn Day 5 - 2/17/14

Today was a busy day between work and rehearsal, so I only had about a half hour between the two to work on the english horn. But 30 minutes is more than enough time to get caught in a quagmire. I'm pretty efficient at that.

I was doing the last of the swedging that I didn't complete yesterday on the Eb lever. It goes on the C# lever hinge rod, between the two ends of the C# lever. It's a key that gets used a lot, and has force exerted on it at kind of a weird angle, so it was severely worn and needed a lot of swedging. Like, more than I've ever needed to do on a key. You can see on this end how much of a gap there is between the tube and rod.

So I was doing working on that and things were going alright, but I failed to take one factor into account: As metal is worked, it hardens. So as I was swedging, repeatedly squishing and deforming the metal of the hinge tube, the metal was getting less and less flexible, until finally it couldn't absorb the stress being placed on it. That caused the end of the tube to crack in two places. This is something I should have foreseen, but thankfully all is not lost.

To fix my mistake, I first cleaned out the cracks with a fine jeweler's saw, then filled them both with silver solder. In this picture you can see that the left side of the hinge tube looks a little weird. That's the end that cracked, and the slightly darker color is the silver solder that pooled on the outside of the key.





In this next picture, you can see the end of the tube where it split. I didn't bother making the end of the tube look perfect, because that area is going to get cut off when the tube gets shortened in a few steps.

The next step was to file away the excess solder and sand the outside of the tube to restore a smooth finish and remove the distortion from the excess silver solder. It's difficult to see the color in this picture, but filing and sanding also removed the silver plating and exposed the base metal of the key - on this instrument the keys are made of brass. I'll need to buff and spot plate it later to fix that.

Next I needed to ream out the inside of the tube, which got a little bit of solder in it. That's not necessarily a bad thing, since now I can ream it just to the diameter I need so it will fit snugly on the hinge rod, thereby creating a new bearing surface in the tube out of silver solder.

Finally I shortened the tube a bit, since all that swedging made it a good bit longer, and it was no longer fitting between the two sections of the C# lever. This is when any of that nastiness at the end of the tube got removed.

Here's the whole assembly put back together. The Eb lever fits perfectly between the two halves of the C# lever, and fits snugly on the rod. Once it's spot plated, there should be no permanent damage.

Buffet English Horn Day 4 - 2/16/14

Today was devoted to swedging. There's not much to say about that. I did get to use the pliers I made yesterday, though they needed to be thinned out some more to fit some of the upper joint keys. More on that tomorrow. Mostly I try to use my swedging collets wherever possible, as I find them much more consistent and easier to control than the pliers.

The nice thing is that none of the keys were really mangled or completely blown-out, so the amount of swedging I had to do was pretty reasonable, and I'm very pleased with the results.

One consequence of swedging is that it makes the tubing longer. As you squish the tubing, the metal you're displacing needs someplace to go, like rolling out a log of Play-Doh. That means that later some of the tubes will have to be shortened to make them fit between their posts or between other keys. Done carefully, that allows a technician to shorten them just enough that they fit tightly, with no side to side movement at either end. That's how you get really well-fit keys, which move only in one direction - up and down.

Tomorrow is the last of the swedging, and a minor catastrophe.

Buffet English Horn Day 3 - 2/15/14

Today the first day for the body of the english horn to humidify in my super-advanced humidifier - a garbage bag with a wet sponge in it.

In the meantime, I made these swedging pliers today out of an old set of side-cutters that never really cut all that well. Swedging is the process of fitting a hinge tube to its corresponding rod by carefully squishing the tube to reduce its diameter. The idea is to make it so that the tube moves freely on the rod, but with no slop in the hinge. That way the keys can move smoothly up and down without having any wiggle back and forth. It also ensures the mechanism will be as quiet as possible. Over time, the repeated movement of the keys wears out the soft metal of their hinge tubes, reintroducing slop into the equation. However, keys that are swedged properly can go a long time before any slop is noticeable.

They'll be very helpful when I do key fitting tomorrow. I made them especially to get to the short hinge tubes on the upper and lower stack keys where it's difficult to get access.

Buffet English Horn Day 2 - 2/14/14

The universe's gift to me for Valentine's Day was a late opening at the shop due to snow, which meant I could still go in at my regular time (through some less-than-ideal driving conditions) and get some work done on the english horn. Today was a day just for cleaning. I cleaned both the upper and lower joints, then did some light polishing of the bore on the upper joint, which has some gouges in it. It looks like someone may have pushed a sharp implement up there, maybe in an attempt to remove a stuck swab. The damage isn't too severe, and after dressing and polishing it looks a lot better. The wood of the bore on the lower joint is pristine - I almost can't believe how nice it looks after cleaning.

Cleaning the keys was next. I simply ran them through an ultrasonic cleaner for a few minutes, rinsed, then immersed in silver dip to remove the built-up tarnish. This cleaning process is the reason I had to separate all the steel screws from the silver keys before cleaning, as the chemicals in the ultrasonic and the silver dip cause steel to rust very badly within a few hours of exposure. The keys came out great! 

Actually, in the right side of that picture you can see one steel rod that's pinned to its key (the C# touchpiece) and the little bit of rust that started to form after it was cleaned. Fortunately, that will come off.

Here's another shot of what they looked like pre-cleaning, as a comparison (though this one was taken without flash, d'oh!)

Buffet English Horn Day 1 - 2/13/14

As an oboist, I get occasional calls to play in musical pits, and the books often call for english horn. In the past when I've played those engagements I've always borrowed an english horn, but it's about time I have my own. So this post is about a personal project instead of a customer repair. It's a Buffet english horn that needs an overhaul and I intend to play in a show in exactly 3 weeks. Every day over the next 21 days, I'll be posting about the steps involved in this type of comprehensive repair, and chronicle its transition back to a fully functional instrument.

Aside from needing all new pads and corks, a lot of key fitting, and a good cleaning, the instrument appears to be in fair condition. The wood is free of cracks and has good tight grain, and the keywork hasn't sustained any serious damage. The plating is missing in the spots you'd expect, on touchpieces and the tops of keys, but even then it's probably over 95% intact. There is a lot of work to be done facing the tone holes to remove chips and defect from grain, but that's to be expected on an older instrument that's been sitting unused for a long time, as this one has.

There are a few problem spots. One post on the lower joint has had its face filed back, to the point that it will need to be replaced. The outer ring on the D key is split and slightly out of round, so the split will need to be filled and the key rerounded. Then there's this:

The Eb/B lever on the lower joint is bent, and it looks like the impact that bent it also knocked the lower post out of alignment. The threaded hole in the above picture is where that post was installed, and when the post moved it split the wood on the surface. The fortunate this is that the crack doesn't extend into the bore. Hopefully it will all fit back together nicely and make for an invisible repair. Here's another picture, this time with the post inserted. You can see that it's slanted slightly toward the left of the picture.

Day one involved taking a lot of notes, snapping a lot of pictures, and making some drawings for reference. Then it was on to disassembly. Everything came apart with very little resistance. I removed all the keys and springs, then removed all the regulation and adjustment screws from the keys. The silver plated keys and the steel screws can't be subjected to the same cleaning chemicals, so it's necessary to remove every single screw. By the same token, the steel springs on the body shouldn't be subjected to too much moisture, and since I'll be cleaning the body it was necessary to remove them. Plus it's easier to work on the body when it's not covered in tiny little needle springs.

Here are the keys after disassembly, and with the pads removed. They're pretty tarnished, but should clean up nicely. Aside from a few bent parts and one stripped shaft lock screw (for which I think I can make a replacement), things look good.

And here's the body after disassembly. Oof. I need to play this thing in three weeks.

Here goes!