Piston Valve Tension

[brocktorock]

Hey guys. I got a new horn not long ago, and lately the valves have been a little sluggish, so I took it to the local repair shop. We determined it was tension causing the problem, so he's currently heating the joints and braces to try and relieve some of that. My question is, what is most likely the cause of this, and how can I keep it from happening? He said it may have just been like this from the factory, but the woodwind guy says it's my gig bag. Something about the weight of the tuba pulling down on the bag and thus in on the slides. I could see that being the case. Any thoughts, Tubenet? Do I need a hard case, or maybe an upright gig bag instead of a horizontally carried one?

[brocktorock]

It's a Wisemann 900, brand new as of about a month. I'm using a standard B&S Pt-6 size bag, so I think it should be fitting fine. I'm not positive about the tension, but the first and 4th valves were definitely a part of the problem. I believe more of it was around the slides than directly into the valves, but again I'm not exactly sure.

[jsmn4vu]

This is not a simple question. The effect of tension on the valves, of course, is when it is sufficient to deform the valve casing. I think that (in general, not just in your case) simply carrying it in a gig bag is less likely the cause then either an impact while in the gig bag or lifting the tuba by part of the valve section.

[Donn]

There's a zipper on the top, right? Put the tuba in the bag, pick it up as you usually do but with the zipper open. Put your hand in there, where the supposed problem is. In my opinion, if it's bad enough to bend the tuba, you won't easily be able to get your fingers in there (or it's an awfully weak tuba.) If you can easily pass your hand over the valve section, then it isn't caused by just holding the tuba in the bag, and it isn't the bag's fault.

[Dan Schultz]

If your Wiseman is only a month or so old.... AND you haven't dropped the horn on the valve section causing some distorted valve casing ports....

If the horn has a removable valve section, that is likely the cause of the sluggish pistons.

SEND IT BACK TO WHERE YOU GOT IT!

[brocktorock]

I doubt it'll be accepted back as the repair has already been made...