My horn's had a sluggish first valve for a while, and I've not been the best about caring for it in general. This horn is not worth enough, and I have not been paid enough playing it, for it to be worth sending to a professional, plus the work isn't actually that hard. Disclaimer: I do not warrant the information contained in this album to be fit for any purpose; it is merely informational, and not instructional, in nature. I can in no way be held responsible for damage to any instrument that occurs from attempting to replicate this procedure. In other words, perform work on your instruments at your own risk! To address a few points that have been brought to my attention: no less than three people have told me never to use a steel hammer on my valves, as of a day after posting this. If you do try this, please use a nylon, rawhide, rubber, or pretty much anything-but-steel hammer. Brass is an incredibly soft metal, and repairing or remachining valves is not cheap. It has also been suggested to use vinegar diluted 1:1 with water, increasing the concentration only if the corrosion does not come off, to minimize the risk of damaging any platings. Last, please consider carefully whether you want to try doing this yourself. None of the work is terribly difficult, but it is easy to mess it up, and screw ups in this could easily have four digit price tags. Please do not try this if you aren't willing to spend a lot of money or replace your horn in the event you break something.

I always forget how exactly the strings go back on, so I start by taking a picture of them.

A few closeups of each valve help as well.

Starting with the second valve, because I forgot to photograph the first from the beginning. Removing valves is quite simple: Step one: remove the oil cap.

Step two: remove the lever that actuates the rotor. I was able to leave the strings attached through this step, which is going to be nice later when I don't have to restring them. I'll save that for another day, since I need new string anyway.

As I mentioned before, please do not use a steel hammer for this. Nylon, rubber, or rawhide mallets will not damage the brass, but steel has a substantial risk of doing so. Step three: tap the rotor with a hammer. The upper bearing plates are merely press fit, so this should cause them to come out. A light tap should be all it takes; if it didn't come out easily, a trip to a proper instrument repairer would be warranted. It's also probably wise to put something between the hammer and the rotors, as brass is a fairly soft metal. Be sure to hold the horn over something soft for this, but ensure the rotor is free to fall out. I find it sufficient to hold the instrument on my lap for this, though it may not be the wisest method.

That light tap should be enough to pop off the bearing plate. We can now see the rotor itself, with all deposits and oxidization, which have been causing hangups.

Back to the first valve, which was the primary reason I did this whole cleaning - lots of blue gunk (oxidized copper).

The bearing plate: more gunk

The first valve rotor. Notice the design is different from the second - two and three share the same design, while the plumbing around the first and thumb valves requires different rotor designs for them.

The other end, where we can see more of just how bad the problem has become.

Drop it in a glass of vinegar, and on to the next one.

There's lots of the blue gunk in the cylinder as well. I wasn't able to clean much of it off, but professionals will be able to clean these as well as (or better than) I did my valves.

Here we see the thumb trigger's rotor. It's slightly smaller and of a somewhat different design from the others.

The four rotors in their vinegar baths. You can see the vinegar has taken on a light blue tint from all the gunk it's dissolving. Support your local brewery! I should have had a Spotted Cow while using the New Glarus glass here, but I was all out.

I wiped a bunch of the gunk onto a section of fabric from an old pair of jeans. The rotors still looked pretty nasty after I removed them from the vinegar, but after wiping them down most of the gunk came off. However, I can still do better. There's still a bunch of gunk in the edges, and even some still on the faces of the rotors.

Heat is how you really break down that corrosion. I only use this electric kettle for cleaning things, though I imagine with a thorough wash it could be made food safe again. The vapor from boiling or near-boiling vinegar reeks, and it burns when you inhale it. I'd recommend doing this outside, or at least in a well-ventilated area. As this week's highs are in single-digits Fahrenheit, I'll have to do it indoors.

I turned the heat to low and cooked some leftovers for dinner. After I finished my supper, I turned the kettle off and pulled the rotors out. Totally spotless! You can see the patches that were in contact with the bottom of the kettle; I'm not sure whether there was some sort of plating on these rotors, or the finish has just dulled over time. In the first case, the heat removed the plating, which means I'll may have to do this again, and much sooner than I would otherwise have had to; in the second, I merely restored the shine to a few patches. I suppose it's also possible the heat separated the copper from the zinc in the brass (in fact, it looks like the rotors may just be copper, or a very high copper brass), which also probably means sooner corrosion is likely; I wouldn't worry too much, however, as those surfaces should always be covered in oil (another reason to oil your rotors frequently), which should help prevent any oxidizing. I noticed here, it appears someone may have done this before; there are marks scratched or punched into all the rotor components to identify them (you can see them on the caps in the photo of the cold vinegar bath); before I noticed this, I put the screw into the second valve rotor to avoid mixing it up with the third. The two appear to share the same design, but it's possible that there is a subtle difference I didn't see, or that slight differences in the finished parts have worn into the cylinders (or the cylinders have worn into the rotors) differently, making two and three incompatible. As disassembling and reassembling is a rather involved process, I didn't bother to test this.

Here we see the bearing plates and the tops of the rotors. Again, spotless! Time to put it all back together.

This is a tool that's rather easy to make. I don't remember how I came across the wood disc, but a short section of dowel will do. The hole in the center has to be just wider than the raised section of the bearing plate.

The whole surface of the rotor should be covered in a thin film of oil prior to putting it back in the instrument. I like to make sure I can spin the bearing plate a few revolutions with a single flick before I put it back together.

Before replacing the rotor, the cylinder should also be dried (I used an air compressor) and coated with a thin film of oil.

A few taps should get the bearing plate back into place. I believe I had trouble with mine because I had gotten oil on the sides of the plate, which should not be lubricated against the cylinder wall (their job is to stay in place and keep the rotor where it belongs!).

When it's seated correctly, the rotor should have almost no vertical play (i.e., it cannot move up or down within the cylinder), but it should spin almost as freely as the bearing cap spun on the oiled rotor. Often I find a rotor that won't spin is a result of the bearing cap not being fully seated - i.e. it was tapped too lightly. Of course, great care should be exercised in this, as it is the easiest part of the process to cause irreparable damage to the valves.