2 keys not sounding when bellows squeezed

[accordo]

HI everyone,
I have posted before about this problem. I located the faulty reeds that do not sound when bellows squeezed, so I was about to investigate if the reeds were blocked, but before I did, I thought that I might gently blow and suck each reed, expecting them not to sound when I blow/suck, but the reeds sounded fine in both cases. So I assembled the accordion expecting all to be OK,but ,no, same problem! So my question is why do the reeds work fine when I suck/blew each reed and yet do not work when the bellows try to do it. I must add everything else about the accordion is fine. Any suggestions ? I thank you if you for your time .

 

[Tom]

Could there be something blocking the air flow? Malfunctioning voice “slider” perhaps? Or pallet not opening?

You say the reeds don’t sound on squeezing, how about on opening the bellows?

 

[accordo]

Could there be something blocking the air flow? Malfunctioning voice “slider” perhaps? Or pallet not opening?

You say the reeds don’t sound on squeezing, how about on opening the bellows?

Thank you for your reply. The reeds sound fine when opening bellows. This is why I am confused. The slider looks OK and as I wrote, if I gently blow and suck these reeds they work fine. The pallet is opening and closing fine . This has me stumped!!!

 

[debra]

This might be a case where the source/direction of the airflow comes into play. When it is critical whether a note does or does not play you have to consider where the air pressure comes from. Let me explain.
When you pull the bellows the air is sucked into the accordion through the hole in the bottom of the reed block. the sucking action actually sucks on the outside of reed block, thus pulling in the air into the accordion through the reed block. When you take the reed block out and blow into the hole you are pushing the air into the resonance chamber (into the reed block) and the air comes out through the (space around the) reed.
When you push the bellows the situation is reversed: The air is pushed along the (outside) reed into the resonance chamber and then out through the hole. When you such on the hole the air follows the same way but instead of creating high pressure in the accordion, blowing out, your mouth on the hole is creating low pressure to get the air to come through.
When the voicing of the reed is critical the reed may sound when there is low pressure sucking on the hole and not when there is high pressure pushing on the reed (to get the air to go out through the hole). Not only are the forces on the reed different, if the reed has valves as well the valve is sucked open versus blown open and it can work in one way and not the other...
So it may be a difficult problem to diagnose and fix properly. I have encountered this a number of times on high piccolo reeds but in a rare occasion also on low reeds. (With low reeds it's easier to fix as you can just see the voicing error or the valve problem, on the smallest piccolo reeds it's hard to see what's going on, even with a magnifying glass.)

 

[colinm]

Are you sucking and blowing on the correct hole

 

[accordo]

Thank you for replying. For now I will use other register settings as everything works fine it is only on this one register setting that the 2 notes do not sound when bellows are squeezed. I will enjoy playing the accordion as is and look into this problem more deeply at a later date and also replace a lot of the leather valves that have curled upwards.

 

[accordo]

Are you sucking and blowing on the correct hole

Yes,not only did I note their position,but I also tried all of them just to make sure notes are in tune

 

[Ventura]

hi

because you have limited experience, i am going to suggest
an unusual test (when you have time)

the reed pair you are testing.. razor cut the wax and free them,
flip them over and heat the wax to seal them again

re-assemble the accordion and test

now, if you have the same problem still, it proves the air
flow path has the problem, not the reed

if the problem is now on the pull only, you know the problem
is the reed

(flipping reeds over is generally not reommended, because the tuning
is different for the reed facing in vs out)

 

[accordo]

Thanks for that suggestion. Makes perfect sense. I will try.

 

[Glug]

Thanks for that suggestion. Makes perfect sense. I will try.

You probably want to make a note if there's any sign of which way up the reed is.

Some reeds have a line scribed across the corner of the plate to show which side is 'outer'.
If they don't you could always add that yourself.

Here's one from a Scandalli

 

[dak]

One thing that hasn't been mentioned is that reeds respond differently depending on the resonant space they have available. In order not to change the resonant space all too much, you need to try with an extreme "hot potato" mouth with as much free air space as possible inside, both when blowing and sucking.

It also is worth mentioning that particularly accordions that have been dormant some time can harbor some really nasty mold spores that you don't want to have your lungs overgrown with. On the converse, reeds and leathers tend to have a dim view regarding the humidity of human breath.