To Vent or not to Vent...

[USMCTuba]

Greetings All!

I have a PT-10 that seems to seems to have some weird airflow issues. I often get a kind of "blowback" on my embouchure during slurred passages and I have to "pop" all my valves after longer rests. I concentrated on airflow and finger exchanges for two months thinking it was probably me, but when I played on horns at the Midwest Clinic I had none of these flow problems. Will venting the valves of my horn help with this issue? If not, what might?

[imperialbari]

I have no vented valves, but I for the sake of my curiosity would like to piggyback this thread with the reverse question:

Why have some vented instruments had the vents soldered back tight?

Klaus

[Mojo workin']

I often get a kind of "blowback" on my embouchure during slurred passages

Sounds to me like you play a tuba.

Advice: Song and wind.

[Michael Bush]

Why have some vented instruments had the vents soldered back tight?

Could it be that valve wear eventually makes the venting redundant and even problematic?

[imperialbari]

Why have some vented instruments had the vents soldered back tight?

Could it be that valve wear eventually makes the venting redundant and even problematic?

I cannot exclude this consideration being the case sometimes, but that particular valve block, where I saw the resoldering documented, appeared being in a good shape.

Klaus

[swillafew]

My B&S rotary valves pop a little after the horns been sitting. I wonder if temperature difference is enough to cause it.

I don't find it worth investing time in a fix.

[imperialbari]

When the tubing cools the evaporated water in the valve loops will condense thereby removing part of the pressure inside the valve tubing. That effectively creates some vacuum, which will fill with a pop when a valve is engaged. Moving the valves regularly during long rests will minimize the problem.

Klaus

[Dan Schultz]

My B&S rotary valves pop a little after the horns been sitting. I wonder if temperature difference is enough to cause it.

I don't find it worth investing time in a fix.

Yes... the temperature difference between when the horn is being played and then put down for 32 measures or so is enough is the valves and slides are tight. You'll probably never notice on a horn with even a slight bit of clearance.

I don't think so, either. All four pistons on my 1291 were vented when I got it. There is very little reason to pull any slides on the horn so I regard it as a waste of time and money. My opinion, anyway

[swillafew]

Thanks for the feedback. I was a slide puller until I switched to a left hand 5th valve horn, and I have unlearned it since then. Practicing intonation seems to overcome whatever the horn might do.

The outcome of drilling holes in the horn is hard for me to understand.

[Stefan]

The outcome of drilling holes in the horn is hard for me to understand.

I vented the 1st valve of my 2155 and all the valves of my Petrushka are vented. For me, the main reason to vent is to be able to pull a slide without having the valve down. I guess there are other reasons as pointed out by this thread, but I haven't thought about any of that.

Stefan