ot? Machine out stuck trumpet valves?

Just had a guy come to me with a unique challenge. Machine out stuck valves on an antique trumpet. He said he had taken it to a couple of insturment repair places to no avail. I told him to bring it by simply because I'd never worked on a musical insturment.
Anyone have experience with this?
have fun
i_r_

Can you get hold of the valve stems? I'd suggest maybe using an ER16 collet chuck to grab the stem with, and construct some sort of slidehammer extension for the collet holder. I'd imagine corrosion is the issue, and I don't know if chemicals would loosen that up or not. Probably use some heat with the slide hammer for effect.

Played trumpet as a kid. After about a week, you get green slime at the valves (all that wet air you blow into it). Can see that if not cleaned and oiled (there is a special valve oil) before it was put away for 50 years that it could get badly gummed up. The fact that the instrument guys couldn't deal with it is a problem, but if the owner says go for it, tell him what's likely to the FU'd when you're done. I assume that it is not of national treasure value.

John

Kenny Rogers Gambler song.

Sometimes antiques are simply dust collectors, and useful only to admire. Anything you do will likely diminish it's value.

HuFlungDung said:

Can you get hold of the valve stems? I'd suggest maybe using an ER16 collet chuck to grab the stem with, and construct some sort of slidehammer extension for the collet holder. I'd imagine corrosion is the issue, and I don't know if chemicals would loosen that up or not. Probably use some heat with the slide hammer for effect.

Click to expand...

When I wanted a slide hammer collet set-up, I used R8 collets. They are so plentiful they are cheap and used ones are just fine.

Before any of the Slide Hammer use I'd get a pan big enough to submerge it completly and add the universal solvent... WATER... and I'd probly add some vinegar ...make it strong... 50% Water, 50% Vinegar.... test a spot on the instrument to make sure....

Then I'd wait... go about your day to day biz and check it once in a while... if it shows signs of lossening up, wait a little longer... then maybe try the slip hammer idea....

Whatz the hurry??? right??

Light up your oxy/ac torch adjust for proper flame.....
Snuff out fire, blow the mix into tubing.

Light it off.

Ya might want to wear heavy welding gloves....

digger doug said:

Light up your oxy/ac torch adjust for proper flame.....
Snuff out fire, blow the mix into tubing.

Light it off.

Ya might want to wear heavy welding gloves....

Click to expand...

End up with a trumpatubonet.

Trumpets (all brass instruments) are soldered, so the torch is likely to lead to it falling to pieces. The valve cylinders are honed, so machining them is going to destroy it - and no you're not going to go buy some '20 over' valves to fit the bored out cylinder.

I play horn for yeas as a kid. My first one was a handle down from my cousin that used to be my uncles when he was a youngster. it too was frozen when my other uncle got a hold of it for my cousin. He soaked it in acid in the bath tub or so I've been told. It ate all the laquer off, but it is was still a good horn, in fact I still have it today - an Olds Ambassador from the 50's.

I'd try the slide hammer or soak approach. Maybe slight heat and then spraying the valves with freeze spray (hold canned air upside down) to see if they crack loose.

Brent

Antarctica said:

Trumpets (all brass instruments) are soldered, so the torch is likely to lead to it falling to pieces. The valve cylinders are honed, so machining them is going to destroy it - and no you're not going to go buy some '20 over' valves to fit the bored out cylinder.

I play horn for yeas as a kid. My first one was a handle down from my cousin that used to be my uncles when he was a youngster. it too was frozen when my other uncle got a hold of it for my cousin. He soaked it in acid in the bath tub or so I've been told. It ate all the laquer off, but it is was still a good horn, in fact I still have it today - an Olds Ambassador from the 50's.

I'd try the slide hammer or soak approach. Maybe slight heat and then spraying the valves with freeze spray (hold canned air upside down) to see if they crack loose.

Brent

Click to expand...

Nice horn.
As noted, a long soak and gentle force/heat is the only option for salvaging the valves.
It's possible that one of the rust chealators will dissolve the corrosion, beware though, it also eats metal at a slower rate.

YouTube has several good videos on the parts of the valve and how they go together.

Solvent soak seems like a good place to start.

Let us know how it turns out.

Steve

Antarctica said:

Trumpets (all brass instruments) are soldered, so the torch is likely to lead to it falling to pieces.

Click to expand...

Torch is snuffed out, no flames on trumpet at all.

Antarctica said:

Trumpets (all brass instruments) are soldered, so the torch is likely to lead to it falling to pieces. The valve cylinders are honed, so machining them is going to destroy it - and no you're not going to go buy some '20 over' valves to fit the bored out cylinder.

I play horn for yeas as a kid. My first one was a handle down from my cousin that used to be my uncles when he was a youngster. it too was frozen when my other uncle got a hold of it for my cousin. He soaked it in acid in the bath tub or so I've been told. It ate all the laquer off, but it is was still a good horn, in fact I still have it today - an Olds Ambassador from the 50's.

I'd try the slide hammer or soak approach. Maybe slight heat and then spraying the valves with freeze spray (hold canned air upside down) to see if they crack loose.

Brent

Click to expand...

Careful if it is plated....silver usually. If you soak it make sure it will not kill the plating. They are soft, it will end up with a dent in it if you look at it wrong. Use very little heat, you can wreck it in no time if you try to rush it. The valve has a threaded ring that guides the valve rod and stops the finger pad. you can unscrew the finger pad and remove the guide ring. then you can fill the valve tube above the valve with Brake Free, Kroil other penetrating lube. Take your time, it took years to stick, you won't free it in 10 minutes.

There are caps on the bottom of the valve, too... So making a fairly precise pusher, and a plate with a close-clearance hole to push the valve thru, instead of working out a way to pull it. Since the valve stem (at the top) is threaded, pulling on it or placing a threaded puller in the hole will just strip out the threads. Plus, you don't have to worry about the strength of the solder joints around the trio of valves. Of course, don't push the valves out the bottom... only the top.

Valves are often cast and then machined, and are fairly complex. I think they're also hollow inside, for responsive action. Duplication will be tricky, if you're trying to get back to playable condition.

Chip
60's Selmer K-modified, 70's Bach Strat.

Thanks for all the ideas. If he does bring this thing to the shop, I'll document the project.
have fun
i_r_

After removing the bottom and top caps it might be possible to use the old grease packed pusher trick.
Fill the bottom cavity with grease, slip fit a dowel and tap on the end of the dowel.
The grease will transfer the pressure evenly to the bottom of the piston.
That should help get it started, once you reach the ports it will quit working though.

Like popping the bushing out of the back of a crankshaft.

Piston valves on wikipedia has a nice exploded view of a modern trumpet valve.

In my post above, the "pusher" needs to be sized so it presses on the periphery of the valve, not in the center (due to hollowness...) For that reason, the grease-gun approach would be contraindicated. Or even bad.

It would be interesting to know the age and make/model involved. Even mainstream instruments like my Bach can be $6-8000 for ones just slightly older than mine. No offense intended, but something at that level would beg for a more experienced instrument repair shop, or at least guidance by pro's in that field, rather than, well, us. That said, flea markets are full of interesting-looking horns that are worth $50 on a good day with a tailwind.

What you have on your side is the ability to make the right tool for the job, instead of trying to make-do with the wrong tool. Instrument repair shops generally aren't machine shops. (I'm sure there are some, though.) Whether or not the compensation package is appropriate is up to you, of course...

Chip

Is the "guy" a friend or a customer? First, what are the trumpets owner's expectations? The reality is that there is high likelihood that this trumpet will never play again. If the owner is expecting the valve to be restored to working condition, he will be disappointed. If this is a paying job for you you have to manage his expectations.

Trumpet valve pistons are thin tubing that is then has the ports (the valve passages) soldered or brazed in. Then the piston is often plated then honed to fit the casing. The casing is thicker brass with stub tubes brazed on to match the ports. The rest of the tubing is soft soldered together.

The existing piston is corroded in place. First I would soak it in penetrating oil for as long as I could stand - maybe a week or so. Then you could try to drive the piston out with a fitted drift. You could make one to fit snuggly in the casing. It needs to fit tightly in the casing. You want to push on the walls of the piston, not the bottom cap of the piston. You push up from the bottom, NOT the top. There is a keyway in the side of the casing and a closely fitted key, the valve guide, that keeps the valve from rotating. This keyway only goes part way down the casing, so the piston will only come out the top.

You can tap on your drift and hope that the piston comes out without too much damage. But on old instruments it is unlikely.

You could take this to another instrument repair technician. One place to find one would be to check the National Association of Professional Band Instrument Repair Technicians (NAPBIRT) website. They have a website with a tech locator:

Home Page

You could also talk to local school band directors and get some recommendations.

I do this professionally. I would expect that it would take an hour or more to just get it apart. I would not expect it to be playable. If the owner is looking to restore it to playing condition, it will be expensive. The valves will probably need to be rebuilt by plating the pistons, then honing the casings and the pistons to fit. If the trumpet is a valuable antique, you can reduce its value with an inexpert repair attempt.

Sorry to sound negative, but this is work where you have one chance to get it right.

-Jess

You might want to look at a video of how the trumpet may have been made: https://www.youtube.com/watch?v=8NAaRQUTp9g
The video shows the valve piston to be fairly long and complex (not a simple solid cylinder.) If it has corroded itself solidly inside the valve body the body itself may collapse before the piston comes loose.
Here is another one on how a tuba is made. It gives a bit more detail on how the valve section is fabricated: https://www.youtube.com/watch?v=NQIP53NEBIY
Also visit a pawn shop or instrument dealer and see if you can have a close look (take apart) at the valves of a trumpet. Better yet if it is the same make and model. Perhaps take a caliper and a thread gage with you.
Good luck.

-DU-

Miguels244 said:

After removing the bottom and top caps it might be possible to use the old grease packed pusher trick.
Fill the bottom cavity with grease, slip fit a dowel and tap on the end of the dowel.
The grease will transfer the pressure evenly to the bottom of the piston.
That should help get it started, once you reach the ports it will quit working though.

Like popping the bushing out of the back of a crankshaft.

Click to expand...

That works great in a old brake caliper, no chance here. as soon as it moves a bit a port will open up and the grease will do nothing more.