Old Conn valve stems

[Michael Bush]

The local brass repair guy has my big old Conn this week, aligning the valves. He's run into an issue. Presumably due to various more or less half-way done repair jobs in its long life, every valve stem is a different length. This has me wondering if there are any of these stems available out there. I'm thinking it wouldn't be a big job for a machine shop to fabricate four of these, but which one is the right length? It seems better to try to buy them. Any help out there?

[Dan Schultz]

I'm not trying to be 'snarky' here but If your repairman knows low-brass.... he'll be able to easily figure out what to do. If he's stymied by this... take it somewhere else. People working on your horn not knowing what they are doing is what got your horn into the shape it's in.

[Michael Bush]

Well, I'm still planning on bringing it to you next week, so if he doesn't get it solved all hope is not lost!

And I should say I have every confidence in him, just seeing if I could find a way to make things easier.

[SousaSaver]

The correct stems will allow your valves to be in alignment in the up and down strokes with the proper felts or cork. If your repairman has a small lathe and a set of taps and dies, he can make you a whole set of valve stems. I had to make a Conn 20K valve stem a week or so ago because I had just run out and I needed one sooner than it could be ordered.

I have also had to make adjustments to a Martin Sousa's stems that had modified King finger buttons because the original buttons were missing. The stroke was just a hair too short and I had to make an extension for the stem for proper alignment.

This is an easy issue. Let us know how it goes.

[SousaSaver]

Bloke -

Thanks for the info. It seems counter intuitive to use a trumpet style stem design when it would be simpler to manufacture a flush piston and straight brass rod.

[SousaSaver]

Bloke -

Thanks for the info. It seems counter intuitive to use a trumpet style stem design when it would be simpler to manufacture a flush piston and straight brass rod.

time...

It's much quicker (particularly during the summer rush, when sousaphones are encountered by repair folk) to grab an old Martin trumpet stem (if available), silver solder on a bit of brass rod, and trill/tap, rather than...

...grinding off that odd raised female stem receiver from the top of the Martin sousaphone piston, HOPING that the main top plate of the piston is made of thick enough material to support drilling and tapping it directly, and then (though the design it simple, still involving several operations) manufacturing three new stems from scratch (as the replacement stems would have to be quite long indeed, and therefore custom-made).

I was referring to manufacturing at the Martin factory.