Help with Rotary Valves

[theanalogkid]

Hey guys,

So over the break I checked out my school's F tuba. It's been sitting in storage for awhile, and the valves on it have all seized up. My first instinct was to take it to the shop, but it might be there for awhile. So, I figured I'd take a shot at fixing it myself. I don't really know where to start though. Anyone have any suggestions, tips, etc.?

Thanks!

[imperialbari]

Oil top and bottom spindles plus all moving links and the bearings of the transmission (don’t forget the paddle axle). There are ideal oils for the various moving parts, but after storing I would use a very thin oil like Blue Juice generously, as the main point is making the oil penetrate through all friction areas.

This will often free the valves. If not, there are fairly simple tricks, but they better are applied by experienced people. It is most important not to apply force on the paddles to make them move. There is a major risk of skewing the transmission system.

Klaus

[Rick Denney]

Often, they are seized up because of dried mouth crud. Oil may not do the job until the bond is broken. I have often been able to loosen rotors stuck for that reason with a couple of light taps on the stop arm using a small rawhide mallet, applied in the same direction as the linkage. That is a tool that every tuba player should own. Once you break the bond, you'll be able to wiggle the valve and the oil will be able to penetrate much more easily.

Don't be the next guy to cause the problem. When you are done with it, pull the top slide and dribble some valve oil down into the rotors (taking care to hold it vertically so that the drips don't run down the sides, carrying grease with them). Work the oil into the valves before putting the horn away and that will help reduce the chances of it corroding again.

If a couple of light taps with a small mallet and a generous oiling don't work, then the valve needs to be taken apart and thoroughly cleaned.

Remember, light taps with a small rawhide mallet.

This is more of a problem with new tubas in my experience. With older tubas, the rotors have a well-polished oxide patina that will minimize the problem in the future.

Rick "been there, done that" Denney

[UTSAtuba]

Often, they are seized up because of dried mouth crud. Oil may not do the job until the bond is broken. I have often been able to loosen rotors stuck for that reason with a couple of light taps on the stop arm using a small rawhide mallet, applied in the same direction as the linkage. That is a tool that every tuba player should own. Once you break the bond, you'll be able to wiggle the valve and the oil will be able to penetrate much more easily.

Don't be the next guy to cause the problem. When you are done with it, pull the top slide and dribble some valve oil down into the rotors (taking care to hold it vertically so that the drips don't run down the sides, carrying grease with them). Work the oil into the valves before putting the horn away and that will help reduce the chances of it corroding again.

If a couple of light taps with a small mallet and a generous oiling don't work, then the valve needs to be taken apart and thoroughly cleaned.

Remember, light taps with a small rawhide mallet.

This is more of a problem with new tubas in my experience. With older tubas, the rotors have a well-polished oxide patina that will minimize the problem in the future.

Rick "been there, done that" Denney

I more than second these statements. I would leave for break, and my older 186 valves would always freeze up. The above mentioned technique worked all the time, every time.

Joseph

[Ken Herrick]

The advice offered here is essentially good.
BUT

MY advice is - if you don't know what you are doing, find somebody who DOES and go to them and have them show you. Over the years that I was doing repair work I made a lot of $$$$$$$$$ fixing rotary valves which had been damaged by well meaning, but uninformed people trying to service them for the first time. More than once I found strange objects which were jamming valves.

Surely there must be a repair tech or fellow tubist or even (if you can get along with frog horn players) one of those spaghetti players who knows what they are doing (though most of them don't either and resort to doing things like pouring milk down their instruments - a big reason for avoiding sitting behind them.)

It should only take an hour or so to do a good job, including checking alignment and a few bucks spent might save a bigger bill for the instrument being in the shop for an extended period.

[Dylan King]

How important is it to oil the valves under the valve caps, in the back of the horn?

On my new Miraphone 291, I can't for the life of me unscrew the back to get to it, on any of the five valves! They all work fine so far, but in the past I have always oiled under there at least once a month.

I've tried using a towel for grip -- and even as much brut-force as I can muster (and I'm a pretty strong guy). They seem like they were screwed shut by one of the strong-man competition dudes in Germany before the horn shipped.

[rocksanddirt]

I saw a video clip, somewhere that discussed how to carefully disassemble and clean rotary valves for tubas.

http://www.uni.edu/drfun/repair_video/videoindex4.html

check this out....it might give you some pointers on getting the valves free.

[UTSAtuba]

They seem like they were screwed shut by one of the strong-man competition dudes in Germany before the horn shipped.

[Rick Denney]

How important is it to oil the valves under the valve caps, in the back of the horn?

On my new Miraphone 291, I can't for the life of me unscrew the back to get to it, on any of the five valves! They all work fine so far, but in the past I have always oiled under there at least once a month.

I've tried using a towel for grip -- and even as much brut-force as I can muster (and I'm a pretty strong guy). They seem like they were screwed shut by one of the strong-man competition dudes in Germany before the horn shipped.

The small rawhide mallet will help here, too. Strike the edge of the rear cap a glancing blow in the direction of loosening (righty-tighty-lefty-loosey) and that will usually pop the threads loose so that the cap will unscrew. If you can't aim and hit the target without putting a dent in something else, take it to a repair tech. This is, by the way, the prescribed method, not a flaky shortcut. Using pliers is the flaky shortcut. The problem is that threads bind because the metal has deflected into the tightened position so much that the resulting friction defeats the fingers. The mallet causes a shock wave through the part to release that friction, allowing the part to jump out of the bound-up condition. Forcing it slowly with pliers or similar tools doesn't release the binding and if the part is tight enough, the threads will tear and gall.

If anybody damages a rotary valve using light taps with a small rawhide mallet, then either they are not making light taps, using a small mallet, or the valve was already broken. I do not believe it is possible to bend the rotor shaft or damage the stop arm with light taps from a small mallet. Granted, the technique may not work, in which case you are no worse off.

These are basic skills that will keep us from annoying repair techs with repairs so easy they often end up doing them for free to avoid having to write it down.

The F5 small rawhide mallet from Ferree's is what I'm talking about, though I prefer the F11 tapered canvas mallet, especially for the knurled edges of rear rotary valve caps. http://www.ferreestools.com, pages 37 and 44 of their 2008 catalog, respectively.

Rick "who uses the mallet against the side of the receiver to unstick tuning bits and mouthpiece, too" Denney

[WakinAZ]

I've had good luck using a small strap wrench from Home Depot to loosen those pesky back caps. This has worked on two brand new Miraphone tubas and some older crudded up ones. Also a rubbery thing like you use to open jar lids sometimes works on the less stubborn ones. I will invest in a small rawhide mallet one of these days when I get the courage to dismantle my rotary valves.

Eric "offering no technical explanations or warnings with these suggestions" L.

[Wyvern]

I have never had a rawhide mallet and have as a substitute in the past used a normal hammer with piece of wood against the part being freed to avoid damage, but think I will invest in the correct tool for the job. It sounds like a rawhide mallet should be in every tuba player's tool box - particularly those playing rotary tubas.

PS Never seen in the shops, so have just ordered one off Amazon.

[Dan Schultz]

How important is it to oil the valves under the valve caps, in the back of the horn?

On my new Miraphone 291, I can't for the life of me unscrew the back to get to it, on any of the five valves! They all work fine so far, but in the past I have always oiled under there at least once a month.

I've tried using a towel for grip -- and even as much brut-force as I can muster (and I'm a pretty strong guy). They seem like they were screwed shut by one of the strong-man competition dudes in Germany before the horn shipped.

Yes.... you need to apply oil to the rear spindle once in a while. While Rick offered instructions on how to use a small rawhide mallet on the outer edge of the cap.... that is good advice and will often do the trick.

One of the favorite 'tricks' of some repairmen (NOT ME!) to make rotors unbind after doing a poor assembly job of the rear bearing plate is to strike the top of the stop-arm screw. When this is done... it drives the rear bearing plate into the rear cap and causes it to 'lock'. A sharp 'rap' with a small rawhide of plastic mallet smack in the center of the cap will use the clearance in the threads to move the back plate away from the cap and allow it to be loosened my hand.

As others have suggested, though.... it might be better for you to take your horn to someone who is versed in such techniques and let him show you how to do it.

[Chriss2760]

One of my repair gurus recently related to me his concern that electrolysis action in the valves may result in the deposition of rotation-inhibiting accumulations on the surface of the valves. (Gee, did I write that?) Anybody got any thoughts on this?
BTW, he chemically cleans the valves to correct this issue.

[iiipopes]

One of my repair gurus recently related to me his concern that electrolysis action in the valves may result in the deposition of rotation-inhibiting accumulations on the surface of the valves. (Gee, did I write that?) Anybody got any thoughts on this?
BTW, he chemically cleans the valves to correct this issue.

Pop the rotors out, buff the calcium off of them, clean the casings in the usual manner, reassemble, and play. That's what they do where I live, because there is so much calcium in the drinking water (municipal wells into limestone aquafers) that on a bad day, you turn the tap and chunks come out instead of water.

[Wyvern]

One of my repair gurus recently related to me his concern that electrolysis action in the valves may result in the deposition of rotation-inhibiting accumulations on the surface of the valves. (Gee, did I write that?) Anybody got any thoughts on this?
BTW, he chemically cleans the valves to correct this issue.

Pop the rotors out, buff the calcium off of them, clean the casings in the usual manner, reassemble, and play. That's what they do where I live, because there is so much calcium in the drinking water (municipal wells into limestone aquafers) that on a bad day, you turn the tap and chunks come out instead of water.

But how does that calcium get into the valves? My understanding is that the moisture in the valves is mainly condensation. Obviously some spit too, but do inhabitants of hard water areas carry high levels of calcium in their bodies and blow into the tubas they are playing?

[oedipoes]

One of my repair gurus recently related to me his concern that electrolysis action in the valves may result in the deposition of rotation-inhibiting accumulations on the surface of the valves. (Gee, did I write that?) Anybody got any thoughts on this?
BTW, he chemically cleans the valves to correct this issue.

Pop the rotors out, buff the calcium off of them, clean the casings in the usual manner, reassemble, and play. That's what they do where I live, because there is so much calcium in the drinking water (municipal wells into limestone aquafers) that on a bad day, you turn the tap and chunks come out instead of water.

But how does that calcium get into the valves? My understanding is that the moisture in the valves is mainly condensation. Obviously some spit too, but do inhabitants of hard water areas carry high levels of calcium in their bodies and blow into the tubas they are playing?

maybe by cleaning the tuba with tap water?

[Wyvern]

maybe by cleaning the tuba with tap water?

If that is the case, then the message must be to only ever flush the inside of tuba with filtered, or boiled water

[imperialbari]

Players with tendencies towards getting dental calculus will very often see calcium deposits in their instruments.

Klaus

[iiipopes]

Yes, even occasionally in lung x-rays you will see calcium deposits here. We never worry about lead solder verses lead-free solder in the copper water pipes, because within the first year of use they all have a layer of calcium carbonate. Water heaters, unless you purchase a water softener, only have a life span of about two-thirds of the expected life, and before I got my water softener, I completely choked my humidifier on my furnace with the carbonate condensation out of the water.

Yes, calcium ions can accompany the breath into the horn.

[Dan Schultz]

Players with tendencies towards getting dental calculus will very often see calcium deposits in their instruments.

Klaus

From my experience... those calcium deposits often are the breeding ground for 'red rot'. Don't know for sure that they are related but perhaps the same scenario causes both.