4th valve slide falling in

[dsfinley]

The 4th valve slide on my HB-1P keeps slowly falling in when I play. I’ve tried very heavy grease to hopefully remedy the problem but it still persists. There doesn’t seem to be an air leak and the valves are vented so I’m not sure what the problem is. If you have any ideas on how to remedy this i’m all ears

[matt g]

If your 4th valve is vented, then you do have an air leak, albeit on purpose.

You could try some tight o rings on the tubes and see if that keeps it in place.

[Sousaswag]

It's probably a really well-aligned slide! Lucky you

You could get a slide stop added if it's that bothersome, or try getting some REALLY thick grease that isn't necessarily a "brass instrument" brand.

[bloke]

Remove that slide, shine it up nicely, pack it carefully, and send it to Anderson.

Tell them to plate the entire slide, including the tubes.
Politely ask them to handle it gently, explaining that it's particularly nicely aligned.

This is better than having someone mangle the inside slide tubes with an expander.

Using an expander to precision fit a tube to another tube is like using a backhoe to plant a petunia...
(re: the petunia analogy) As seen on youtube, a few people can do it, but can your guy do it?

OK...It's really not THAT hard, but it's REALLY easy to mess up, go too far, and they the end up going back-and-forth with sandpaper/buffing and the expander (EEK !!!)

information:
The added silver will be about .0004" thick, and barely thicker at the very ends of the inside tubes (once plated over).
This means that your inside slide tubes will probably come back roughly .0008" additional o.d. and perhaps .0010" o.d. at the very ends of the tubes.
You can use 1000 grit sandpaper (AutoZone) and valve oil on them (particularly at the ends) if its just a smidge too tight.

=================================

I would expand them gently - were it mine - but (again) I don't know who your local horn-fixers are nor how talented they are.
Also - as all of those tubas were shipped to the USA silver plated - it seems like a handy solution to me.

[dsfinley]

If your 4th valve is vented, then you do have an air leak, albeit on purpose.

You could try some tight o rings on the tubes and see if that keeps it in place.

Currently using this o ring fix and it works fine!. If an air leak occurs from the slide being worn I will probably send it off as Bloke suggested. As I am very cheap and don’t make much from playing I will rock along this way for a while…

[bloke]

They wouldn't charge you all that much to plate one slide.

[LeMark]

I'm sure that would fall under their minimum charge of $25

[cjk]

The 4th valve slide on my HB-1P keeps slowly falling in when I play. I’ve tried very heavy grease to hopefully remedy the problem but it still persists. There doesn’t seem to be an air leak and the valves are vented so I’m not sure what the problem is. If you have any ideas on how to remedy this i’m all ears

Do you ever have to push it all the way in while playing? If not, maybe pull out the bottom fourth valve slide to a fixed position, then keep the top fourth all the way until you need to pull it out? In other words, let the top one be all the way in, then tune the bottom one.

[bloke]

@cjk

That sounds like a helpful suggestion. I'm not one who ever grabs my #4 slide - at least not if I can help it, but there are some players who move that slide a lot. I don't know if he still does, but Gene P. used to move that slide a whole bunch on his big C.

[arpthark]

The 4th valve slide on my HB-1P keeps slowly falling in when I play. I’ve tried very heavy grease to hopefully remedy the problem but it still persists. There doesn’t seem to be an air leak and the valves are vented so I’m not sure what the problem is. If you have any ideas on how to remedy this i’m all ears

Do you ever have to push it all the way in while playing? If not, maybe pull out the bottom fourth valve slide to a fixed position, then keep the top fourth all the way until you need to pull it out? In other words, let the top one be all the way in, then tune the bottom one.

+1. I can't think of a time I've ever had to push #4 in. I set the bottom slide on my Eastman where D is in tune, and will pull 4 for C# and occasionally low G.

[cjk]

@cjk

That sounds like a helpful suggestion. I'm not one who ever grabs my #4 slide - at least not if I can help it, but there are some players who move that slide a lot. I don't know if he still does, but Gene P. used to move that slide a whole bunch on his big C.

The HB-1P is a 4 valve HB CC, so I'd expect the OP to need to move that slide quite a bit.

[dsfinley]

I'm sure that would fall under their minimum charge of $25

Wow, I didn’t realize it would be that cheap. I’ve never really gone down this rabbit hole before.

[dsfinley]

@cjk

That sounds like a helpful suggestion. I'm not one who ever grabs my #4 slide - at least not if I can help it, but there are some players who move that slide a lot. I don't know if he still does, but Gene P. used to move that slide a whole bunch on his big C.

The HB-1P is a 4 valve HB CC, so I'd expect the OP to need to move that slide quite a bit.

I’ve not found much need for moving the 4th. The first, absolutely.

[bloke]

Pointing that out to me, I'm guessing that it was bought used and maybe a previous owner I had that slide made to slide really easily for tuning solutions that they came up with.

[the elephant]

There doesn’t seem to be an air leak and the valves are vented…

If your 4th valve is vented, then you do have an air leak, albeit on purpose.

If an air leak occurs from the slide being worn…

This is not specifically aimed at @dsfinley but is for future players who Google this specific issue, or valve venting in general.
_________________________________

Just providing some clarity, here. Matt means that the vent makes your slide LEAK LIKE A SIEVE.

Valves are vented for two reasons.

First, they allow you to rapidly move slides for intonation purposes without having to work out the timing to avoid the very audible (and "feel-able") "pop" that happens if you move the slide first, and then press the valve. It allows the air pressure inside to stay more or less equal to that of the open tuba you are blowing into. Instead of working to time slide pulls to the same, exact moment as you press the valve, you can move the slide slightly in advance of the valve's actuation, so that "pop" will not happen.

Second, if your valves are in excellent condition (wear-wise) and well-oiled, every time you press a valve it will have a tiny "pop" as the slightly warmer air you are putting into the horn interacts with the cooler air inside the slide loop. Some people are very much bugged by this; in some cases, you can feel this as you slur a line. Some people get all their valves vented to remove the airtight seal and stop the popping.

"Venting" a valve intentionally destroys the airtight seal of the slide loop to allow the air pressure to self-equalize, whether due to a slide pull or push, or just due to a temperature difference between the open horn and the closed-off slide loops. Only the active part of the horn needs to be airtight, and when the valve is up the slide loop is not active. The vent is placed in a location where it can "breathe" when the valve is up, but it is plugged when the valve is down.

THEREFORE (You trusted that I would eventually get to my point, right?) If you have a slide worked on to allow it to more easily be moved for pitch reasons, some like the "touch" adjusted to be so loose that only the vacuum nature of the closed slide loop keeps it in place. If this is a top slide, when you are playing the air pressure acts like a pillow to keep it "afloat", and if you put the horn down on its bell the airtight nature of the loop acts as a vacuum to hold the slide in place. Venting a valve removes that airtight seal, so the slide can move freely via its own weight, falling in or falling out at a speed that depends on how large the vent hole is. If the vent is very small the slide will fall out (or in) very slowly, and vice-versa.

I am posting this less for the OP and more for any future Googlers who do not understand what getting their valves vented does to the horn. If you have a tricked-out slide and you vent your valves, you will probably have to add a slide stop to keep the slide from falling out or have the inner tubes plated, as per Joe's suggestion, to tighten it back up some.

Best of luck!