How much does felt settle in half a century?

[KiwiSqueezer]

May I ask the experts here a couple of questions?

I am slowly (oh, so slowly!) rebuilding a couple of accordions. Both date from the 1950-60s and show no evidence of having been worked on before now. They both have 'clattery' actions, the pallets closing somewhat noisily, if allowed to 'free fall'.

I don't know how much noise is acceptable, never having handled a new instrument (I'm pretty new to this...), but, since there's also moth damage to some pallets' felt, I will probably renew all the pallet facing felt and leather.

First question: how much settling or permanent deformation of pallet felt is to be expected? The ancient felt is quite firm, and measures 4mm thick, but is it likely to have started life 5mm thick? Should I replace it with 5 mm or 4 mm thick stuff (I'm resigned to re-aligning the pallets on their rods)?

Secondly, on a CBA, with stepped keyboard (85 buttons), what is a typical treble button travel and force required (weight)? I've read George Bachich's words on setting up piano accordion keyboards, but can't find any advice about button boards, and assume the rules may be different for them.

 

[debra]

Afaik the felt+leather comes in thicknesses from very thin up to about 4.5mm. Over time the leather suffers most from being squished. A temporary fix is to brush the leather against the grain to raise the "hairs" and that will reduce the clacking noise, but not for very long. I would suggest to replace by 4.5mm felt+leather.
The force required on a CBA (and on PA alike) varies a lot between instruments. The strength of the springs needs to be enough to keep the pallets closed so there are no air leaks, but not more than that. The amount of force required is a lot higher on a 5 voice accordion than on a 2 voice accordion. Typical keyboard travel is around 3mm, about the thickness of the button tops. It's about the same on a stepped button keyboard and on a flat button keyboard. Key travel tends to be larger on PA, but it varies more as there is more room to adjust it during construction (or repair).

 

[KiwiSqueezer]

Thank you - very helpful. On this CBA, button travel is limited only by the felt ring under the button (for all I know, this is how they all are), so I suppose I must expect this felt to change a bit, and get thinner and stiffer, with age. I'll check that the low-note pallets open sufficiently with your suggested amount of button travel. It should be straightforward to set up the box 'mechanically', in other words to function correctly, but I didn't know whether CBA players, especially 'crawlers' liked more resistance, so they can feel their way around, without the risk of inadvertent button pushes.

 

[debra]

Thank you - very helpful. On this CBA, button travel is limited only by the felt ring under the button (for all I know, this is how they all are), so I suppose I must expect this felt to change a bit, and get thinner and stiffer, with age. I'll check that the low-note pallets open sufficiently with your suggested amount of button travel. It should be straightforward to set up the box 'mechanically', in other words to function correctly, but I didn't know whether CBA players, especially 'crawlers' liked more resistance, so they can feel their way around, without the risk of inadvertent button pushes.

The felt ring under the buttons (and felt strip under the keys in a PA) is only compressed when a button or key is pressed (which is less than 1% of the lifetime of an accordion). The felt+leather under the pallets is compressed all the time when the button or key is NOT pressed, so that is over 99% of the time.

 

[kimric]

I have found that the felt under the keys tends to be on the thinner side and gets more abused since the keys get pressed down as had as you care to press the keys,this tends to be harder than the spring pressure on the pads, and the pads typically are larger in surface area.
Piano felt (this is a woven and combed fabric) works really well under the keys and is available in different thicknesses.
You can "needle" the felt pads to re fluff them , but I will often use a air compressor and a narrow tip to fluff up the pads to good effect and this will work well to fluff and clean the leather too.
Vince Cirelli ( designed and serviced accordions for Colombo) said the pads would pack no matter what and the keys would always get louder. This was the reason a bunch of companies tried foam rubber foam in the 50's. This worked great till it did not.

 

[RowanSumner]

I've just picked up an accordion from the 70s, the pallets are in good order but the under key felt is very compressed on about half of the keys and basically good as new on the others. Its strange some of the bushings (for side to side) look almost new, others squashed, others not present.

 

[boxplayer4000]

KiwiSqueezer: A picture of the keyboard, particularly of the keys near the top and bottom, would have been helpful.
It's very likely that when the accordion was new the keys at the extreme ends, normally A and F on a 'full size' accordion, would have been level with the keyboard ends. It's a choice that's never let me down when I was choosing the pallet felt/leather.

 

[KiwiSqueezer]

Boxplayer4000: Thanks for the brain wake-up. I hadn't thought of that, even though I 'knew' it... I can check whether the pallets lift if the keys are aligned as you (and Bachich) suggest. Lifting suggests pallet felt has taken a permanent set. I'll certainly do that, for the piano keyboard. But for the CBA's button keyboard, things are less convenient: it has no reference plane, against which to set the buttons' alignment, when 'up'. In my ignorance of CBA playing technique, I don't know whether the very different finger action is best served by button travel and weight quite different from piano keys. Debra suggests a button travel somewhat less than the piano key travel suggested by Bachich. I guess he should know!

 

[boxplayer4000]

KiwiSqueezer: I agree. The setting up may be simpler in a piano keyboard.
I think I would be looking closely at the keys/buttons at the extreme ends (high and low) for guidance. Quite often some of those are 'dummy', ie. unplayable and will not likely have moved/compressed much since they were installed.

 

[KiwiSqueezer]

Good idea! There's one dummy, so that should at least provide an idea of original button felt thickness, and an alignment reference. Thanks!