Treble pallets misalignment cause air leaking

[JerryAccordion]

Hi everyone. I have a problem that I want to know how to solve it.

I was checking the air leaking by holding an accordion by two hands on the right side and bellows were moving down. During this test I noticed the air leaking on the treble side. I tried to fix by putting pallets under correct angle but it wasn't successful. What do I need to do in this situation?

 

[Gonk]

It can be hard to align the pallets without seeing the leaks. You can check with a lamp to see exactly where your leaks are. Remove the treble end, the reedblocks, and the grill, and hold it up to the lamp in a dark room.

 

[debra]

The trick I learned to check for pallet alignment is to press the key, place a cigarette-paper (thinnest kind) under the pallet and release the key. The force needed to pull out the paper should be the same for all pallets,
The other trick (already mentioned) is to remove the reed blocks, put the treble side over a bright lamp, turn on the master switch (all voices engaged) and see if there is any trace of light coming through anywhere. The light points to where the leaks are.

 

[Glug]

For aligning the pallets I carved a dummy soft wood pallet with square pegs that fit snugly in the endmost air holes.
Then you just put the dummy pallet in each pallet position and draw round it with a felt tip (comes off with meths).
Then adjust the real pallets to stay inside the marks.

My Hohner already had some similar lines marked (I think they were original) but they were very faint.

 

[Ventura]

The trick I learned to ...... place a cigarette-paper (thinnest kind)

i am thinking Cannabis Rolling paper may be better... then re-used
for the original purpose

 

[JerryAccordion]

I have photos of the one of treble pallets. I would like to know is it in good shape or not.

 

[Ventura]

this looks like a student level Settimo i recall from the 60's or so.. modern
by accordion standards.. the pallet is somewhat self-leveling actually
due to the rubber mount

the problem is with the middle of the sandwich... the Aluminum is still
reliable, and actually the leather/suede pad surface looks decent,

the problem is the middle is not Felt, but a more modern (and short lived)
alternative man made material that was ill-advisedly used for a period of time

it is actually good that you caught this now, as under prolonged heat or UV light
(like sunlight from a storefront window) this entire middle material just ages and crumbles
into powder, which is a real pain to get out of the reeds and action as it gets everywhere

the distortion from "flat" is because the material is itself distorting and going critical

it is a medium hard job to do, but mostly takes patience and reasonable skill with
the sharp Scissors and razor.. you will need to cut new "middles" from a good proportioned
piece of high quality Felt, and remove the old crap from EVERY key pad then glue on the new Felts,
using the old leathers is OK but it would be better to put new ones on too

there are a few tricks to glueing, so look at old Threads on the subject for tips

good luck

 

[debra]

I have photos of the one of treble pallets. I would like to know is it in good shape or not.

These pallets look to be still in good shape. But the foam material that was used may eventually disintegrate completely. The preferred material nowadays is felt (plus leather for the seal of course).

 

[nagant27]

Anyone when replacing these in a tone chamber accordion do all the low and middle in the chamber first and then do the non chambered pallets second? Or do you replace both at the same time? I was thinking if you do just the chamber first you can test it with the reed blocks in before starting the outside the chamber pallets.
btw always use the rolling paper for the intended use after checking the pallets, other way around could lead to some strangely placed pallets ?

 

[JerryAccordion]

What can you say about condition of the pallet/leather/foam rubber/ lever arm based on photos below?

 

[debra]

What can you say about condition of the pallet/leather/foam rubber/ lever arm based on photos below?

The most telling is the 5th photo (150555). The pallets are not felt+leather but foam+leather and foam tends to permanently compress more than felt. The pallet is more compressed near the top of the photo than near the bottom, which indicates that the pressure on the pallet has been uneven for years already. Although the pallets are otherwise still good (the foam isn't yet disintegrating like I've seen on old Atlantics) I'd recommend replacing them and then ensuring the levers are adjusted in such a way that the pressure is equally spread over the whole pallet (which you can test with the cigarette paper test).

 

[Glug]

If you look at the last photo the pallet on the left of the one removed is out of alignment by about 2mm.
It should be inside those corner marks.

 

[JIM D.]

Just to answer a couple of questions here. When replacing pallet facings on a tone chamber box -- the tone chamber pallets
will have to be installed first, tested for leaks & then apply the none tone chamber facings . There are now quality self adhesive
valve paddings that will when applied properly will out last the instrument itself.

FRM Enterprises – Accordion Parts and Piermaria Accordions – Valve Padding

frment.com

 

[debra]

... There are now quality self adhesive valve paddings that will when applied properly will out last the instrument itself.

Do you have good experience with them, also with the behavior over time? The last time around when self adhesive valve paddings were introduced the term "Klebemorino" was born a few months later...

 

[JIM D.]

I've been using them for some 20 years now. Not only self adhesive but saves labor time , a quality product & and so far have
no complaints in performance .
The great advantage is when buying by the sheet is that you can cut the padding for many pallet dimensions.


They do not in any way have " Klebemorino" tendencies.

 

[JerryAccordion]

If you look at the last photo the pallet on the left of the one removed is out of alignment by about 2mm.
It should be inside those corner marks.

Did you mean according to holes and recesses in valve bases in pallets?

 

[Glug]

Nope, I'm looking at the corners of the pallet relative to the 'corner' marks on the soundboard:



It looks to me like the 'corner' marks are orginal and the pallets should be centered on those (if the marks are accurate).
An easy way to check is to look at the leather face on that pallet and see if the pillows are centred.

 

[JerryAccordion]

May incorrectly installed valves to the deck to match the stamped recesses in the base of the valve to cause air leaking on the treble side?

 

[Glug]

The leather on the pallet facing needs to be centred over the air holes, that matters the most.
If the pallet facings were put on correctly then the pallet being centred on the corner marks will achieve that.

You can see on your first photo above (the one of the pallet facing) that the pillows are centered on that pallet facing, so there's an equal amount of leather on all sides to form the air seal. If the pillows are too far off centre air will probably leak.

 

[Ventura]

the valves were correctly installed originally,
and the foam was soft and pliable when new...

it is time to change them ALL and re-align the action arms

every single one of them

much easier dealing with this completely and be done with it