Stuck screw rim

[bububassboner]

I have a LOUD LM-7 that i got from a member of this board and the rim is VERY stuck on it. How should I go about getting it unstuck?

Thanks in advance

[pgym]

Getcherself a coupla these:



(Strap wrenches)

Wrap one around the rim, the other around the cup (3-piece mpc) or shank (2-piece) and turn in opposite directions.

[tubatom91]

That seems to be the easiest solution, although you could do it the old fashion way and soak it in penetrating oil for a week or two and then give it a shot. Hell my Grandpa freed up a sleeve valve engine with a mixture of Iodine and transmission fluid . You could try that but I doubt you'd end up with a mouthpiece you'd want to play on .

[SplatterTone]

"If it jams, force it. If it breaks, it needed replacing anyway."

[Alex C]

What? You don't have slip-joint pliers?

[oedipoes]

What? You don't have slip-joint pliers?

there's nothing wring with slip-joint pliers, if a piece of leather is applied between pliers and metal surface of whatever you want to unscrew.

I managed to unscrew the bottom caps of the rotary valves of my 70 years old kaiser tuba that way, not a single scratch.

[Dan Schultz]

What? You don't have slip-joint pliers?

there's nothing wring with slip-joint pliers, if a piece of leather is applied between pliers and metal surface of whatever you want to unscrew.

I managed to unscrew the bottom caps of the rotary valves of my 70 years old kaiser tuba that way, not a single scratch.

I've been known to use leather-lined pliers in very rare cases. But... EXTREME care must be taken to avoid distorting the caps from the pressure. Once a cap (or even worse... the casing) is bent... the project is pretty much over unless you have the mandrels to straighten things our again.

Hey kids.... stay away from your horns with pliers. And.... most definitely keep your dad's hands away!

[jonesbrass]

pfft.

Tap the side of the rim rigorously with a rawhide mallet.

This is right. As a tuba player who does some of his own basic maintenance and owns a rotary horn, I happen to have a rawhide mallet around . . . doesn't everyone?

[Dan Schultz]

pfft.

Tap the side of the rim rigorously with a rawhide mallet.

This is right. As a tuba player who does some of his own basic maintenance and owns a rotary horn, I happen to have a rawhide mallet around . . . doesn't everyone?

I just happen to have a rawhide mallet... but I usually can't find it. However... one thing that always resides in the kitchen is a big wooden spoon. A few sharp raps with one of those will usually loosen stuck sousa bits, too.

[oedipoes]

What? You don't have slip-joint pliers?

there's nothing wring with slip-joint pliers, if a piece of leather is applied between pliers and metal surface of whatever you want to unscrew.

I managed to unscrew the bottom caps of the rotary valves of my 70 years old kaiser tuba that way, not a single scratch.

I've been known to use leather-lined pliers in very rare cases. But... EXTREME care must be taken to avoid distorting the caps from the pressure. Once a cap (or even worse... the casing) is bent... the project is pretty much over unless you have the mandrels to straighten things our again.

Hey kids.... stay away from your horns with pliers. And.... most definitely keep your dad's hands away!

I did not mention the fact that my kaiser just came back from repair, and the valve caps had been unscrewed by the tech for maintenance.
He just turned them too tightly together to unscrew by hand (for lubrication). A gentle push with the pliers did the trick.
The stuck rim on the mouthpiece might just be in the same case, being turned together by hand too tightly.
I hold a masters degree in engineering and I do know the consequences of wrong tooling and unprofessional handling of mechanical constructions (like tubas).

I do appreciate your concern and I hope I did not make anyone to destroy part of his/her tuba with my unthoughtful, too short writing (during my 30min. lunch break).

Wim (my dad stays miles away from my horn)

[DavidK]

Remember:

Lefty-Loosey
Righty-Tighty

Good luck!

[Dan Schultz]

.... I've been known to use leather-lined pliers in very rare cases. But... EXTREME care must be taken to avoid distorting the caps from the pressure. Once a cap (or even worse... the casing) is bent... the project is pretty much over unless you have the mandrels to straighten things our again.

Hey kids.... stay away from your horns with pliers. And.... most definitely keep your dad's hands away!

.....I do appreciate your concern and I hope I did not make anyone to destroy part of his/her tuba with my unthoughtful, too short writing (during my 30min. lunch break). Wim (my dad stays miles away from my horn)

Oh... I wasn't being critical of you personally. Just speaking the truth in the fact that much of what I see by way of repairs is the direct result of someone making an honest attempt at fixing music instruments.

Perhaps the reason why those back caps were tight as soon as the horn came back from the repair shop is that a favorite 'trick' of many repairmen is to give the stop screw a little 'rap' in an effort to make the rotors turn more freely. This drives the rear bearing plate into the back cap and often causes a 'lock' condition. If that's the case, then a sharp 'rap' with a rawhide mallet in the center of the back cap will send the rear bearing plate back where it REALLY belongs and allow the back cap to turn freely.