Tech/maintenance Key Rod Wobble

[SaxBerg]

I have a saxophone where the key rod wobbles inside the bottom post right hand (lower stack). The key rod is fitted from below, so the wobble is at the slotted end of the rod. A consequence of this defect is that there is a lot of movement in the low "D" key.

I have read that one common way to repair key rod wobble inside posts is to use a special set of pliars to compress the post head.

Is there a DIY or temporary fix for this kind of problem? Is it possible to fit a sleeve on the key rod inside the post? Teflon tape?

 

[Stephen Howard]

Sounds like a soprano? They usually have a rod screw that's inserted via the lowest pillar.

It's a fair bet that if you have wear in the pillar then you also have it in the key barrels...unless it was made that way.
The common fix is to 'peen' the pillar with a special pair of pliers. A better fix is to ream out the pillar and fit a bush - or ream out the whole stack and fit an oversized rod screw.

Bodge fixes include hammering a flat on the end of the rod screw so that it wedges into the pillar. This is not a reversible fix.
Another bodge is superglue. Undo the screw until the threaded end just comes out of its pillar then screw in back in half a turn. Degrease the exposed end of the screw (don't degrease the pillar), then pop a drop of superglue on the rod. Do the screw up and clean off any dribbles. Check the D key still moves. Leave for a couple of hours. You can also use epoxy adhesive - it's easier to clean up because it takes much longer to set.
A slightly more 'advanced' version of this fix is to put a blob of soft solder on the rod - but this will only work if you have a gas gun and a lathe.

Teflon tape will work but it tends to be one hell of a job to get it to follow the rod into the pillar.

 

[SaxBerg]

Sounds like a soprano? They usually have a rod screw that's inserted via the lowest pillar.

It's a fair bet that if you have wear in the pillar then you also have it in the key barrels...unless it was made that way.
The common fix is to 'peen' the pillar with a special pair of pliers. A better fix is to ream out the pillar and fit a bush - or ream out the whole stack and fit an oversized rod screw.

Bodge fixes include hammering a flat on the end of the rod screw so that it wedges into the pillar. This is not a reversible fix.
Another bodge is superglue. Undo the screw until the threaded end just comes out of its pillar then screw in back in half a turn. Degrease the exposed end of the screw (don't degrease the pillar), then pop a drop of superglue on the rod. Do the screw up and clean off any dribbles. Check the D key still moves. Leave for a couple of hours. You can also use epoxy adhesive - it's easier to clean up because it takes much longer to set.
A slightly more 'advanced' version of this fix is to put a blob of soft solder on the rod - but this will only work if you have a gas gun and a lathe.

Teflon tape will work but it tends to be one hell of a job to get it to follow the rod into the pillar.

Thank you very much for providing such excellent advice! I have recently read the article "Swedging the keywork - pros and cons" on your website, and together with the information above, I now have some basic knowledge about repair of the saxophone keywork.

I might try a DIY temporary fix of the key rod wobble with teflon tape, but I will probably have to have find a good saxophone technician for a proper repair.

 

[PigSquealer]

@Stephen Howard I wonder if a dab of HMG on rod end would do ? Cooled then running in. I think the pillar would just scrape off the excess to a net fit. Non intrusive and reversible.

 

[skeller047]

On my Beaugnier alto, the pivot screws have some kind of goo on the threads to keep them from turning. If I ever clean that stuff off, I will put purple Loctite on in its place. These are “headless” pivot screws which are screwed in until the key starts to bind, then backed off a little (like 1/8 turn) so the key moves freely. I know other horns have a slit in headless pivot screws with some kind of rubber or plastic wedge that accomplishes the same thing.

The point being, for a loose rod screw, is purple Loctite on the threads a viable approach until you can get it to a tech? And what about clear nail polish? That seems to be a time-honored bodge…

NB - purple Loctite is weak and will hold a fastener in place, but the bond is easy to break. It’s meant to be temporary. Don't use regular Loctite anywhere on a saxophone.

 

[Pete Thomas]

Don't use regular Loctite anywhere on a saxophone.

But isn’t regular loctite also temporary? Ie not budge with regular loose but should give way under the force of a tool like a screwdriver or wrench?

 

[skeller047]

But isn’t regular loctite also temporary? Ie not budge with regular loose but should give way under the force of a tool like a screwdriver or wrench?

There are several grades of Loctite. Some are permanent and once cured cannot be released without damaging the material.

The standard “red” Loctite requires heat from a torch to let go, which makes it unsuitable for use on a sax, as solder also lets go at those temperatures.

The color grades are an indication of how strong the bond is. They also have numbers, but lots of people use the informal color descriptions. Purple is the weakest, number 222, and is made specifically as a low strength thread locker.

I probably shouldn’t have even mentioned this, so I will say again, don’t use Loctite on your sax unless you really know what you are doing. Only the “purple” Loctite 222 is safe on a saxophone. Even the blue grade is too strong, it’s meant for automotive use. And only use a tiny bit of the stuff.

 

[Stephen Howard]

@Stephen Howard I wonder if a dab of HMG on rod end would do ? Cooled then running in. I think the pillar would just scrape off the excess to a net fit. Non intrusive and reversible.

I've never got it to work - it's just too viscous even when hot.

 

[Stephen Howard]

The point being, for a loose rod screw, is purple Loctite on the threads a viable approach until you can get it to a tech? And what about clear nail polish? That seems to be a time-honored bodge…

NB - purple Loctite is weak and will hold a fastener in place, but the bond is easy to break. It’s meant to be temporary. Don't use regular Loctite anywhere on a saxophone.

It's not that the rod screw is loose, it's that the pillar at the head of the screw is worn - so the screw can move in the lateral plane.

While purple loctite (222) is the go-to for action work there are times when blue (243) is better suited to the job in hand. You can also regulate its holding power by using it very frugally rather than splashing it all over (a li'll dab'll do ya). In any event it gives way with modest heat.