Is it harmful to squeeze the bellows without pressing any key?

[Ashmalan]

Myth? Exaggeration? or wise advice?
My mom always said this is harmful and I'm trying to understand how true this is.

I've been reading this thread and have not fully understood the answer.
Can it harm the accordion to squeeze without pressing buttons? What damage can it do? Is it okay to squeeze the bellows to test air leakage without applying strong pressure?

Thanks.

 

[debra]

It is not harmful when you don't press too hard. You're not trying to pop the bellows like a balloon!
Squeezing the bellows without pressing any key is in fact something that only accordion repairers should do, to search for air leaks. (Pulling the bellows without pressing any key is also part of this search for leaks, depending on where the leak is.)

 

[murathan]

It may make harm to the valves maybe. Or leakage to the bellows.

 

[jozz]

might harm your shoulder

 

[Vladimir M.]

It's the same as pushing the gas pedal fully to the floor in a car with a manual transmission without being in gear.

 

[dak]

It is not harmful when you don't press too hard. You're not trying to pop the bellows like a balloon!
Squeezing the bellows without pressing any key is in fact something that only accordion repairers should do, to search for air leaks. (Pulling the bellows without pressing any key is also part of this search for leaks, depending on where the leak is.)

A rare time when I find myself in disagreement with Paul. Squeezing the bellows hard will work against the pallet/key springs and open the pallets before anything bad can happen. Some people even use this as an "air button" for getting the accordion ready fast for another phrase on the draw.

This works best for full registrations (since then more pallets connected to the same key/button/piston are being pressed), does not work at all for "silent" registrations used with MIDI-equipped acoustic accordions, and it only(!!!) works on push.

On the draw, the pallets are being sucked closed instead of being pushed open, so indeed here you put your bellows in danger as the weakest link.

Even on the push, the bellows should not be open too much so that it isn't tempted to engage in evasive maneuvers.

 

[debra]

A rare time when I find myself in disagreement with Paul. Squeezing the bellows hard will work against the pallet/key springs and open the pallets before anything bad can happen. Some people even use this as an "air button" for getting the accordion ready fast for another phrase on the draw.

This works best for full registrations (since then more pallets connected to the same key/button/piston are being pressed), does not work at all for "silent" registrations used with MIDI-equipped acoustic accordions, and it only(!!!) works on push.

On the draw, the pallets are being sucked closed instead of being pushed open, so indeed here you put your bellows in danger as the weakest link.

Even on the push, the bellows should not be open too much so that it isn't tempted to engage in evasive maneuvers.

You are right that most likely the pallets will start leaking air before anything bad happens to the bellows.
You cannot use this as an "air button" though: that only works when you press many keys, with full registration, not when you don't press any key. Also, the register has no influence on how many pallets are involved in pressing a key or button because it's always the same number of pallets (unless you use octave couplers/decouplers instead of real registers).
Accordion repairers push with single-reed registers to find which pallet is closing with the least amount of strength. That note will start playing first when no keys are pressed. Very useful for pallet (arm) adjustment. Not really advisable to do it while playing. It essentially serves no purpose during play. Only the push with MANY keys and/or bass buttons can serve as an air release to close the bellows rapidly.

 

[dak]

You cannot use this as an "air button" though: that only works when you press many keys, with full registration, not when you don't press any key.

Different topic. When you press keys yourself, there is no need for pallets to get pushed open by air pressure.

Also, the register has no influence on how many pallets are involved in pressing a key or button because it's always the same number of pallets (unless you use octave couplers/decouplers instead of real registers).

I protest against my déclassement being called an unreal register. At any rate, "pallet" was a bad choice of word by me (though the separate pallets of a cassotto instrument would count): the relevant metric is "pallet area" for each note since the total force delivered by the bellows pressure is given by multiplying the pressure with the area it acts on, and that area most definitely differs with the registration. The total force conveyed through 4 registration slider holes on a pallet is larger than the force conveyed through a single hole.

 

[debra]

Different topic. When you press keys yourself, there is no need for pallets to get pushed open by air pressure.

I protest against my déclassement being called an unreal register. At any rate, "pallet" was a bad choice of word by me (though the separate pallets of a cassotto instrument would count): the relevant metric is "pallet area" for each note since the total force delivered by the bellows pressure is given by multiplying the pressure with the area it acts on, and that area most definitely differs with the registration. The total force conveyed through 4 registration slider holes on a pallet is larger than the force conveyed through a single hole.

Sorry, I didn't mean to be unkind towards your déclassement. It is a bit like the bass side "decoupler" found on the old Scandalli Super VI and some other accordions (if I'm not mistaken).
The total force through 4 registrations slider holes is indeed larger (4 times) that of the force conveyed through a single hole. With all four holes open you can see how much total air loss the accordion has (on push). With just one hole open you can more easily detect when a pallet isn't closing evenly on both ends.

 

[Rosie C]

It's the same as pushing the gas pedal fully to the floor in a car with a manual transmission without being in gear.

ooh, the vrooooom-keh-keh-keh sound! At least on my car after we fitted a rev limiter

 

[dak]

Sorry, I didn't mean to be unkind towards your déclassement. It is a bit like the bass side "decoupler" found on the old Scandalli Super VI and some other accordions (if I'm not mistaken).

I know the déclassement mechanism (as used in the Morino Artiste D series) pretty well and the "decoupler" not at all, so I have no idea about how they compare.

The "push pallets open with bellows pressure" physics for déclassement are kind of nightmarish. When decoupled, the déclassement pallets are held closed independently by their own individual springs (their air holes are never closed by register sliders). When coupled, they can be opened on their own by air pressure too, but the non-déclassement pallets cannot be pushed open without also opening the déclassement pallets.