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How to unstick piston valves?

Posted: Mon Jan 16, 2017 11:58 pm
by Sous-Chef-Phone
Dear TubeNetters,

After a rehearsal tonight with my university's marching band, I discovered a beautiful Yamaha sousaphone in the storage cabinet that seems basically untouched! People apparently don't like to use it because the fiberglass ones are lighter, but this thing is basically pristine, has a longer neck (which works well for me, because I'm on the tall side) and has a really big sound--at least on the fundamental (see next paragraph). I'd be happy to put up with a little shoulder pain if I could play a horn as nice as this one on a regular basis. (no pics, sorry)

The PROBLEM is that all of the valves are completely immovable. They must have sealed up because people left the thing idle for such a long time. I unscrewed one of the valve caps and the whole thing seems dried up on the inside.

This thing is really nice, so I definitely don't want to risk damaging it by doing something amateurish and stupid. Could somebody give me a few recommendations on how to properly unstick the valves without hurting the horn? I apologize if there's already a thread for this, since it seems like a common problem; i just couldn't locate it with a search for "unstick valve". (The slides probably need to be pulled, but I have a little more experience dealing with that.)

Thanks,
-Sous-Chef-Phone :tuba:

Re: How to unstick piston valves?

Posted: Tue Jan 17, 2017 12:05 pm
by Dan Schultz
bloke wrote:I could outline a few methods here or in a private message, but I won't...too many words, and too much chance for damage.

Take it to a reliable repair-guy and have him free them. They will be able to do it while you wait. If they don't seem particularly busy and tell you otherwise, I'd recommend taking it somewhere else. (To me, that would hint that they may have little more experience at freeing lime-cemented pistons than do you.)

...and leave the bell and case in the band room.
PERFECT advise!

Re: How to unstick piston valves?

Posted: Tue Jan 17, 2017 12:15 pm
by tclements
I would STRONGLY suggest you bring it to a repair tech. There are a MYRIAD of ways someone could mess it up.

Re: How to unstick piston valves?

Posted: Tue Jan 17, 2017 12:18 pm
by thevillagetuba
Speak to your director and get an invoice for the tech they use and bring it there. It shouldn't cost you anything more than the gas to get there and back as it is a school horn (did a similar thing a number of years ago during my undergrad).

Re: How to unstick piston valves?

Posted: Tue Jan 17, 2017 12:55 pm
by Sous-Chef-Phone
Thank you for all the great advice! You're right, at this level of deterioration, it's probably the job of a real repairperson. I'm not an officer in the band or anything, so I'll need to talk to them about the logistics. I'll let you know how it turns out!

-Sous-Chef-Phone

Re: How to unstick piston valves?

Posted: Tue Jan 17, 2017 11:41 pm
by Art Hovey
If they are stuck really badly of course you must take it to a good repair person.
But here's what I would do to find out if that will be necessary. (I have done this many times with many different tubas and have done no damage yet.)

First, run some water through the valves and let it soak in. Then remove the button from the top of one of the stems.

Hold something like a hardwood popsicle stick over the top of the stem and tap on it a few times with a small hammer as if you were driving a very small nail. Don't hit it hard enough to bend anything. If you are lucky the piston will start to move after several taps. If not, then take it to someone.

Re: How to unstick piston valves?

Posted: Wed Jan 18, 2017 8:33 am
by Bill Troiano
Maybe this wasn't smart, but as a band director, this happened many times, especially to tubas and euphoniums, if they sat around for too long without being used. I would unscrew the top and bottom valve caps. Place the instrument with the bottom of the valves facing up, on a folded towel or soft surface to catch the valve when, and if, it fell out. Then from the bottom, I would use a snare drum stick and a rawhide hammer. I would place the bead end of the stick in the center of the bottom of the valve. Then I would tap the other end of the stick. Usually, the valve would fall onto the towel. After a few taps, if it didn't fall out, then I would have to send it out for repair. Actually, for top action instruments, I had someone place their hands underneath to catch the valve.

Re: How to unstick piston valves?

Posted: Wed Jan 18, 2017 10:28 am
by opus37
bloke wrote:Yamaha sousaphones, in particular, have small (easy to bend and break) threads on the bottoms of their valve stems, as well as thin-wall valve casings. Further, I believe this person is a teenage person, without the authority to take action nor (likely) the funding in place to cover any boo-boos that might occur.
I've unstuck valves from many old horns. My method involves using a solution (water, valve oil, penetrating oil, etc.) and a little tapping. In this case, I agree with Bloke, it is a school horn. Have their tech do it.

Re: How to unstick piston valves?

Posted: Wed Jan 18, 2017 10:45 am
by NCSUSousa
For the one summer that I helped in the repair shop (as a teenager), I had to give it to the tech when I found stuck valves or slides.
I wasn't allowed to unstick any slides or valves during that summer, and for good reason - too much can go wrong.
I 100% agree with Bloke's answer on this one.

Re: How to unstick piston valves?

Posted: Thu Jan 19, 2017 12:27 pm
by Sous-Chef-Phone
I'm very grateful for the home remedies people are suggesting; thanks! I should clarify that our "marching band" is actually really small; it's one of those "scramble bands" that doesn't really drill or march in arrangements. I don't think we often send out instruments for repairs, so we don't really have an established "tech". (That's why I was so shocked when I discovered this really nice sousaphone; apparently we got a really big donation that year for one? Most of the stuff we have is kind of beat up.)

There's a place in the area that I got a very rough quote from. It might be worth trying one of those water-/oil-based valve remedies WITHOUT the hammering to see if I can loosen or free the valves before we send it out for a $60-$250 repair, but otherwise it might need to get taken in. I'll talk to the band officers (who are also students) to see what they think is best, since they're ultimately the one with the decision authority for what we should try.

Re: How to unstick piston valves?

Posted: Thu Jan 19, 2017 9:06 pm
by acjcf2
While I'm not an instrument repairman I have however, unseized pistons in an engine block by letting some penetrating oil soak and creep around the affected piston. I would think by removing the top and bottom caps and applying valve oil oil some other light oil (Marvel Mystery Oil) should do the trick.

Re: How to unstick piston valves?

Posted: Fri Jan 20, 2017 12:10 am
by J.c. Sherman
bloke wrote:I could outline a few methods here or in a private message, but I won't...too many words, and too much chance for damage.

Take it to a reliable repair-guy and have him free them. They will be able to do it while you wait. If they don't seem particularly busy and tell you otherwise, I'd recommend taking it somewhere else. (To me, that would hint that they may have little more experience at freeing lime-cemented pistons than do you.)

...and leave the bell and case in the band room.
+1 (except for the bell thing... I hate not having the whole instrument. Let me free the valves and toot it to make sure all's well).

Re: How to unstick piston valves?

Posted: Sun Jan 22, 2017 10:58 pm
by Sous-Chef-Phone
The "warm water" suggestion worked a little! I was finally able to remove the stuck caps on the bottom of the pistons, and after a lot of soaking and finagling, i was finally able to unstick the first valve. However, in the process, i wound up cutting my finger up pretty badly, because the loostened piston finally gave way and pinched it like a guillotine.

Afterwards, i also unscrewed the finger button shaft like an idiot, allowing the felt to become uncentered and re-jam the piston a second time. (And with my injured finger i don't have the grip strength to free the top valve cap.). Getting it professionally fixed is starting to seem extremely appealing...