How do reed gaps get wider?

[Ed S]

My only accordion thus far is an 80-plus year old Cellini that is probably "totalled", in the automotive sense; that is, it would cost more to fix it up than to buy a similar one that is well-maintained. I last had it worked on about 40 years ago. One problem it has is that some notes require a lot of air to start playing. I opened it up, and many of the larger reeds have a very wide gap; that is, the moving end of the reed is far from the plate. I understand that this is probably the source of the reluctance to vibrate described above.

How do reed gaps widen on their own? It has not been shipped. I have driven some with it on its back in the car, which is bad for other reasons. But can that bend the reeds? When I get a good accordion, I don't want this to happen to it!

 

[Dingo40]

Our member, Debra, is well informed about reeds, gaps & all things relating to tuning: he'll probably respond
In the meantime, I wonder if some of the gaps you're describing aren't original?
Not all gaps are meant to be "airtight ", to coin a phrase .
BTW, I have a PA 41/120 getting on for 80 years old. Over the years it's had considerable tuning and "valving " and has been behaving very well for the past 30 to 40 years: so, don't jump to conclusions in haste. All is not necessarily lost!

 

[debra]

I understand the thinking that because air is blown through the gap to make the reed vibrate it must result in the gap widening over time (over many years). However, the physics is actually quite the reverse. The physics is just like that of an airplane wing. The shape and angle of the wing causes air to move over the wing faster than under the wing. That creates low pressure over the wing and higher pressure under the wing and pulls the wing up (and the whole plane with it). When air goes through the gap between reed tongue and reed plate the air moves faster over the underside of the reed than over the upper side, so the reed is actually pulled towards the reed plate. (If the gap is too small the reed is sucked in and the note doesn't sound, which is called "choking". Normally the "spring" effect of the steel is enough for the reed to not be pulled in all the way but instead start vibrating.) This happens all the time as you play: the reed is pulled inwards a bit more than it is pushed outwards, so over many many years the gap actually gets smaller, not larger.
In practice this effect is negligible. The only reeds I have ever seen to be really influenced over time are the smallest piccolo reeds. And some reeds that came from the factory with the gap a bit too small may develop more of a choking problem over the years as well.
There is something else that has a huge influence on (especially large) reeds starting slower over the years: the valves don't close as well as they used to. When you play a note one reed sounds and the valve next to that reed is closed so no air is wasted through the hole for that reed. When the valves no longer close properly when the note isn't being played when you start air is first wasted through the hole next to the reed that should play, wasted to suck the valve closed. Only when that valve is sucked closed does the reed start playing. The problem in diagnosing this is that it gets very gradually worse over time, so people get used to the notes starting slower and slower and think that the slow response is just a normal property of an accordion, whereas it is a sign that the valves no longer stay closed.
So you should definitely not change the gap of the (large) reeds, but you should fix the valves so they stay nicely closed when the note isn't being played.

 

[Ventura]

hey Ed S

co-incidentally, there is a pre-war Cellini currently in play on Craigslist

Vintage Cellini Novara Italian Accordion - musical instruments - by...

Vintage Cellini Novara Italian Accordion. Untested. Worn as shown.

washingtondc.craigslist.org

just in case you might want some spare parts for a labor of Love re-building project

it is my long habit to generally monitor accordions for sale in a 200 mile radius or so
on Craigslist

the ebb and flow of brands and models available over time is enlightening...

oh, Debra, there is also an old Pigini Ellegard chromatic for less than $1000 right now that
i bet you could fix up and make a small fortune on in Europe

 

[debra]

...

oh, Debra, there is also an old Pigini Ellegard chromatic for less than $1000 right now that
i bet you could fix up and make a small fortune on in Europe

Thanks for the tip, but I'll pass. Since it's a Pigini it probably has been tuned to 442, whereas everyone around me either has 440 or regrets seriously to having bought 442 without knowing about it. Changing the tuning from 442 to 440 is pretty bad for the reeds, so I wouldn't do that. And I'm also generally not interested in getting involved in accordion sales. I will stick to just repairing and tuning accordions for people I know well.

 

[Ed S]

Thanks much, everyone!
Debra, by "fix the valves" you mean "replace the lifted/curled valves" - right?
I've never read that they can be literally be fixed.

 

[debra]

Thanks much, everyone!
Debra, by "fix the valves" you mean "replace the lifted/curled valves" - right?
I've never read that they can be literally be fixed.

If the leather valves are still flexible enough you can remove them, curl them back and straighten, then glue them back and put the booster spring back on. The valve needs to stay flat against the reed plate when the note is not being played. If leather valves do not have a booster spring, you need to add one and then the note will be out of tune and needs to be tuned again.
If the valves are not flexible, replace by new ones (and add new booster springs as well.
To replace the valves on the inside of the reed block it is easiest to just take the reed plates off and put them back on with new wax.
Yeah... once you start doing maintenance it quickly becomes a lot of work!

 

[Ffingers]

If the leather valves are still flexible enough you can remove them, curl them back and straighten, then glue them back and put the booster spring back on. The valve needs to stay flat against the reed plate when the note is not being played. If leather valves do not have a booster spring, you need to add one and then the note will be out of tune and needs to be tuned again.
If the valves are not flexible, replace by new ones (and add new booster springs as well.
To replace the valves on the inside of the reed block it is easiest to just take the reed plates off and put them back on with new wax.
Yeah... once you start doing maintenance it quickly becomes a lot of work!

Identify a problem; open instrument to fix it; find dozens more problems to fix.
A bit like that half hour job on the car!

 

[Ffingers]

...as I was saying...

One small issue turning into a HUGE project. No choice, it had to be resolved #diy #houseextension

www.youtube.com

A corollary to Murphy's (sods') Law

 

[debra]

Identify a problem; open instrument to fix it; find dozens more problems to fix.
A bit like that half hour job on the car!

Indeed! People (friends) do come to me asking to tune a few notes they can hear are out of tune. So I open up their accordion and have to fix...
1) Noticing decades of piled up dirt and debris under the keyboard and grille and inside the bass mechanism...
2) So complete disassembly of the keyboard and bass mechanism is needed to do a thorough cleaning.
3) The pallets may have disintegrated and/or hardened and may need replacing.
4) Then opening up and noticing the bellows gasket tape has completely disintegrated and needs replacing.
5) Leathers have turned into what looks like cardboard, completely stiff, and need replacing. Plastic valves if they are present may have been glued incorrectly and fall off when you touch them. Reed plates fall off because the wax holding them in place has turned very brittle.
6) If reeds are all rusted the accordion is declared "total loss" and needs to be discarded. If the bellows cardboard has sprung several leaks it may also be time to order new bellows.
7) The underside of the reed blocks needs to be checked, whether it is totally straight or is warped. If needed sanding must be done to straighten them.
8) After everything is fixed, with new wax, new leathers, and enough time for the wax to completely dry and settle it is time to put everything back and check that the reed blocks are held firmly in place and there are no air leaks.
9) Often bellows tape is worn at the back or bottom (in the playing orientation) and needs to be replaced.
10) Finally tuning can begin. With any luck it may be possible to find one or two reeds (among several hundred) that are within acceptable tolerance from being "in tune". The other several hundred reeds all need to be tuned...

For all these reasons I now only deal with good quality accordions, not too old, and only from friends. Only then is there a reasonable chance that the accordion needs little more than just a complete tuning job. So far every accordion I received for tuning needed work besides just tuning.

 

[Beemer]

If the leather valves are still flexible enough you can remove them, curl them back and straighten, then glue them back and put the booster spring back on. The valve needs to stay flat against the reed plate when the note is not being played. If leather valves do not have a booster spring, you need to add one and then the note will be out of tune and needs to be tuned again.
If the valves are not flexible, replace by new ones (and add new booster springs as well.
To replace the valves on the inside of the reed block it is easiest to just take the reed plates off and put them back on with new wax.
Yeah... once you start doing maintenance it quickly becomes a lot of work!

Always great when I learn something new from you! You said 'If leather valves do not have a booster spring, you need to add one and then the note will be out of tune and needs to be tuned again'
Why will the note be out of tune just because a booster spring is added?

 

[debra]

Always great when I learn something new from you! You said 'If leather valves do not have a booster spring, you need to add one and then the note will be out of tune and needs to be tuned again'
Why will the note be out of tune just because a booster spring is added?

The frequency of a note goes down as the valve offers more resistance. The booster spring adds resistance by trying to keep the valve closed. You always need to "tune" valves (and thus booster springs) so that the resistance evolves exactly such that the frequency of the note stays constant as sound volume changes. Often accordions have some notes that clearly go up in frequency as you play harder (so the valve offers too much resistance at low volume) or goes down a lot (so the valve does not offer enough resistance at low volume. It can be quite hard to get acceptable behaviour...

 

[Beemer]

Now understood and similar to tuning inside or outside the bellows. Thanks, Ian

 

[tcabot]

there is also an old Pigini Ellegard chromatic for less than $1000 right now

Damn, it even has chin switches!

 

[Ventura]

ikr ?

they say chromatic's just are not a big market in the USA

same fella appears to have a FR7xB under $1000 too.. these have both
languished on CList for awhile now

 

[tcabot]

At least Pigini is C-griff, so I won't be losing sleep over it.
But the prices across the pond make me cry - in the UK $1000 will buy you a clapped out Hohner student with a couple keys missing.