TromboneChat

I would like to get some techs ideas on whether or not it hurts the valve to pull out the F tuning slide
and hear a "pop"?
I have a Thayer valve.
I always used to depress my valve in order to avoid the "pop". I read in some posts that it is good to pull the F slide out without depressing the valve when oiling the spindle shaft.

Thanks

When you are oiling the spindles it's good to pull the tuning slide of the attachment without actuating the valve. This puts a slight vacuum inside the attachment that pulls the oil into the spindle. Pulling to a pop is not going to do any good. The pop is the release of the vacuum and you lose the force enhancing your lubrication. Put on the oil, pull to a slight vacuum (maybe a couple of inches (5 to 7 cm) and leave it. Then actuate the valve and push the slide back in.

If you are not lubricating the valve, pulling to a pop does nothing for your valve. I would suspect it may do some bad things to it.

I was told in high school by my teacher to not pop the valve unless you were oiling the valve because the vacuum being made and suddenly unmade could mess with the compression or seal. I'll be honest I am not scientifically inclined enough to know if that is true or not, but my valve does seem to need less maintenance if I keep it unpopped.

It's not going to hurt anything unless you have soft components to your valve like o-rings that weren't designed for the pressure. But since all trombone valves to my knowledge only have metal faces making the seal, "popping" the valves really doesn't do any harm. But why do it?

Fun fact, on a Hagmann valve the cap is not screwed but pressed, and the seal of the cap is made by an O ring. When the ring gets old and needs changing, it can happen that you push the tuning slide in and forget to press the valve, and the cap will pop flying off your horn

Unless you REALLY pull it, I doubt you would get enough pressure to hurt anything. Thayer valves are not the tightest sealing valves, so getting a pop from them can be hard.

However, I would still try to avoid doing it, as you can possibly end up sucking "crud" , "gunk" into valve areas.

Following the prevailing advice to pull the slide to draw in oil when oiling the rotor spindle, (as Bruce mentioned above) it must also suck in air which would displace some of the lubricant when popping at other times, thus reducing the lubrication and requiring more frequent oiling...not a huge downside, but since you asked....

noordinaryjoe wrote: ↑Wed Feb 03, 2021 7:33 am Following the prevailing advice to pull the slide to draw in oil when oiling the rotor spindle,

If it really does. I've never seen it happen. I can put a drop on the spindle and pull the slide, and watch the drop just sit there.

timothy42b wrote: ↑Wed Feb 03, 2021 7:41 am

noordinaryjoe wrote: ↑Wed Feb 03, 2021 7:33 am Following the prevailing advice to pull the slide to draw in oil when oiling the rotor spindle,

If it really does. I've never seen it happen. I can put a drop on the spindle and pull the slide, and watch the drop just sit there.

Definitely works on my edwards thayer.

timothy42b wrote: ↑Wed Feb 03, 2021 7:41 am

noordinaryjoe wrote: ↑Wed Feb 03, 2021 7:33 am Following the prevailing advice to pull the slide to draw in oil when oiling the rotor spindle,

If it really does. I've never seen it happen. I can put a drop on the spindle and pull the slide, and watch the drop just sit there.

Remember, the vacuum will take the path of least resistance to equalize itself. If you put a drop of oil on one spindle and leave the other dry, the air will preferentially be sucked in from the dry side, On my conventional rotors I put oil on the shaft under the actuator, then a drop on the bearing under the removable cap. THEN I pull the tuning slide to create the vacuum.

Kdanielsen wrote: ↑Wed Feb 03, 2021 7:59 am

timothy42b wrote: ↑Wed Feb 03, 2021 7:41 am

If it really does. I've never seen it happen. I can put a drop on the spindle and pull the slide, and watch the drop just sit there.

Definitely works on my edwards thayer.

That makes sense. I think axial valves inherently have larger clearances than rotary.

I recommend _not_ pushing the trigger paddle to counter your pull of the F-slide. That much pressure on the trigger is too much stress for the solder joint of the trigger's main pivot bridge. This joint can break and ruin your week.

The issue is unique to trombone with F-attachment. Other brass don't have the breakage factor to consider when pulling slides.

Better: Hold the instrument by its fixed braces, move your thumb _away_ from the trigger paddle, then pull the F slide.

sferg wrote: ↑Sat May 08, 2021 1:12 pm I recommend _not_ pushing the trigger paddle to counter your pull of the F-slide. That much pressure on the trigger is too much stress for the solder joint of the trigger's main pivot bridge. This joint can break and ruin your week.

The issue is unique to trombone with F-attachment. Other brass don't have the breakage factor to consider when pulling slides.

Better: Hold the instrument by its fixed braces, move your thumb _away_ from the trigger paddle, then pull the F slide.

I just hold it by the bell brace and sort of cradle the linkage in an open position with my palm. No pressure on the paddle or linkage, and the bell brace can handle it.

If the slide is attached, then you can just hold the trigger down normally since the stress will be on the slide tenon.

Definitely need to release that pressure, but without putting that much pressure on the lever.

Letting out the pressure definitely decreases the chances of flying tuning slides.

The amount of pressure here is very small in the great scheme of things and will not do any harm to an instrument made of METAL.
I was told that in the very old days of seamed tubing it was discouraged as it was thought it might weaken the seam.
Having made loads of seamed tube , it would have to have been very badly fabricated for this to be the case.

BellEnd

My hypothesis is that some obnoxious 6th grader kept popping them in a class and a band director told them they'd break their instrument... thenone of the more impressionable students went on to spread that and it went "viral" after that.

Matt K wrote: ↑Sun Jun 06, 2021 8:16 am My hypothesis is that some obnoxious 6th grader kept popping them in a class and a band director told them they'd break their instrument... thenone of the more impressionable students went on to spread that and it went "viral" after that.

harrisonreed wrote: ↑Sat May 08, 2021 3:58 pm

sferg wrote: ↑Sat May 08, 2021 1:12 pm I recommend _not_ pushing the trigger paddle to counter your pull of the F-slide. That much pressure on the trigger is too much stress for the solder joint of the trigger's main pivot bridge. This joint can break and ruin your week.

The issue is unique to trombone with F-attachment. Other brass don't have the breakage factor to consider when pulling slides.

Better: Hold the instrument by its fixed braces, move your thumb _away_ from the trigger paddle, then pull the F slide.

If the slide is attached, then you can just hold the trigger down normally since the stress will be on the slide tenon.

I disagree with your last sentence. My rule of thumb is always, whether the hand slide is attached or not, don't press the trigger when pulling slides. Pressing the trigger to counteract the F-slide pull may break the trigger bridge joint eventually.

The former head of instrument repair for the US Army band did a clinic at my school once. He said that the whole "don't pop your valves" thing was started by bad manufacturers so that you couldn't tell that their valves had bad compression. He said it does no harm at all and is actually a good way to see if the valve has good seal.

sferg wrote: ↑Mon Jul 12, 2021 4:17 pm

harrisonreed wrote: ↑Sat May 08, 2021 3:58 pm

If the slide is attached, then you can just hold the trigger down normally since the stress will be on the slide tenon.

I disagree with your last sentence. My rule of thumb is always, whether the hand slide is attached or not, don't press the trigger when pulling slides. Pressing the trigger to counteract the F-slide pull may break the trigger bridge joint eventually.

Hmmm. That would only be the case of you were countering the tension of pulling the slide WITH the trigger. That wouldn't be good in the long term

fsgazda wrote: ↑Mon Jul 12, 2021 5:13 pm The former head of instrument repair for the US Army band did a clinic at my school once. He said that the whole "don't pop your valves" thing was started by bad manufacturers so that you couldn't tell that their valves had bad compression. He said it does no harm at all and is actually a good way to see if the valve has good seal.

So, will an axial valve pop? Might be a good comparison. I only have a traditional rotor, 1971 vintage, but it still pops.

Axial valves will pop, if they're fitted correctly.