Water key question

[CaptPat]

I have a Bach Strad and the water key retaining screw backs out of the threads in the support leg. I first noticed this when the screw had backed out completely from one of the support legs, a bit more and the spring and lever would have detached. Since then I routinely check that the screw is fully seated, it still will back out over time if not attended to. Is this normal for this type of water key? Is there any benefit to adding a bit of blue Loctite for peace of mind?

[gord-o]

That's different. Usually those screws are frozen in place on a Strad and it's difficult to get them out. Usually when a screw is working itself loose it's because the screw is bent slightly or the waterkey itself isn't round. That could happen if the tuning slide was dropped and it hit the floor right on the waterkey, which would make the tube of the waterkey slightly oval in that spot and possibly bend the screw. I'm just speculating here. The fix involves taking the waterkey off, checking that it's round and straight inside, probably replacing the screw and spring and cork. Not too expensive really. The Loctite fix wouldn't hurt to try if you don't have a local shop that can do the fix. Hopefully this helps!
_________________
Richard Hastings
Brass and Stringed Instrument Repair,
Popplers Music

[CaptPat]

I thought the situation was odd as never had an issue with other trumpets I've owned. The instrument was new when I got it, neither the instrument nor the slide had been dropped. I'll take a look to see if there might be some misalignment.

[zaferis]

An unusual thing.. I'd put some clear fingernail polish on the nut or threads, then the next time I was near a good repair tech have them take a look.
I'm also thinking that it's a sign of something being bent, threads stripped, or broken.
_________________
Freelance Performer/Educator
Adjunct Professor
Bach Trumpet Endorsing Artist
Retired Air Force Bandsman

[LittleRusty]

One thing to consider is that there are people who state that loosening that screw slightly has a positive effect on the instrument. Locktite blue, which is what I would use, or nail polish might reduce the effect. I used locktite blue on my high school aged son’s Bach to retain the third valve retaining nuts.

I personally didn’t find any difference playing with the water key, but a one well respected tech posted about this.

[yourbrass]

I use a socket wrench for Bach waterkey screws. I think it's 1/8", haven't looked at the size in a long time.

I'd caution you against taking it apart as the spring has a heavy tension and is not easy to reassemble. Typically, when I service these keys, it's a new spring and cork that are installed.

Oil on the screw is a good idea and light tension when tightening. You might play with the tension a bit and see how the sound changes - it does.

Good Luck!
_________________
"Strive for tone." -John Coppola
Edwards X-13
ACB MV3C /ACB A1/26 backbore
https://yourbrass.com/

[CaptPat]

The screw looks okay, but the spring looks a bit funky, the coil on one side is doubled onto itself and the leg on that side seems shorter than the other side. I ordered both and may try to replace them. I've never used a wrench or ratchet on a water key screw before, not convinced this is the time to start. In the meantime, a little oil on the screw and I check that the screw is finger-tight before every session.

[yourbrass]

Changing the spring will be a challenge - they have a very stiff tension, and then should be bent around the bridge legs and cut. I don't recommend it as a self-service thing.

What you could do more easily is change the cork. That alone will make a difference and you won't have to disassemble the key.
_________________
"Strive for tone." -John Coppola
Edwards X-13
ACB MV3C /ACB A1/26 backbore
https://yourbrass.com/

[CaptPat]

On a careful examination the spring seems okay. No sure why changing the cork will help, the current one seals just fine.

[LittleRusty]

[yourbrass]