My beautiful Greg Mouton Bb accordion with bellows spacer. The action seems to be the same as other accordions. I like the way it looks.

Decorative only! But I think for the older boxes it was necessary because longer bellows were either not available or too expensive.
Note: If you do it with a 20 fold bellows you will lose a fold effectivly making your bellows shorter. (Count the folds on Joanie's)

It is my humble opinion that modern usage of a bellows divider, other than for a bandoneon, is a design "affectation"...

Why anyone needs more than 16 even 14 folds is beyond me... with modern accordeons and modern bellows' stretching them out is "performance" oriented and not a functional necessity.

I would believe that the early use of dividers was because of the the current technology and materials available..

There may be some sort of cool factor but to me its kinda like a continental kit on a family sedan..

As the player of a Mélodie (fait en Québec) with double-bellows I can confirm the effects of it. The bellows divider serves as a time machine, transporting the player and listener back to the 1930s. The music sounds better and everyone seems to want to dance more and drink more eau de vie when the accordion with the bellows comes out.
So, in answer to your question, the divider is "only for show" -- or is it?
;)
-Andy

The music sounds better?

perception or reality

I like the look of the double bellows...

The only advantage I can see is they look nice.

If they added to the performance, all the pros would be using them.

Perhaps at one time they had a purpose but that seems to be lost to history.

The purpose is not lost to history

It was the method used to fold the cardbaord that prevented using longer bellows

Simply easier to use a divider

Look at bandoneons 3 dividers lotsa and lots of air and very long bellows.. same with the Chemnitzer Concertina

I agree that if there was a performance advantage.. they might be more popular

My conclusion.. they look good but unnecessary

You're right, but it's somewhat less tedious to make shorter bellows, so with a divider you essentially make two shorter bellows. I believe the Mouton double bellows are made by cutting a pre-made (Italian) bellows. The Quebecois builders buy pre-folded cardboard (also Italian) so they would actually make two separate (shorter) bellows that are glued to the frame.

I like the way they look on a one-row box. Combined with custom fabric (from boxer shorts or nightgowns) they make for a fairly unique box that is not overly flashy. ;)
-A.

True ion Mouton and true on the Quebec builders

Clement Breton told me the fabric he used on my accordeon came from his wife's nighty..
Hmmm...


Also you can build a wood frame around the center fold of the bellows without cutting the bellows....
tres simple

The all important question is: Are the center dividers mitered at the joints?

Craig,

It doesn't really matter , as the joint receives a small metal decorative corners, and is covered anyways with material.

Graig, as an aside, Mr. Greg Mouton, "routinely" mitters all his frames (4) corners.

He also, recently told me, that he was going to use different striking Pallets or "Tappers" as he brillantly called them.

The new ones are going to be made of a synthetic material.

As you may know, theses have in most cases , shown a nasty propensy to swell their end grain, resulting especially after beeing painted, to a rather visually unsightly result.

Also his "Tappers" rocking arms, are made of a special alloy, meaning, that they permanently shine.

As you know most "arms" are made of cooper and are either hand or spray painted.

Nevertheless, I love the dividers on his accordions, and I know that you didn't ask for a "Report" but I thought that theses informations would be usefull to all.

Claude.

No butt they ain't butted either...

there's a better way... the cowboy way

Seal all end grain with hot hide glue and sand smooth. This will eliminate swelling and over absorption of any stain. Do the same for mitered cuts so the glue up is even and strong. I rarely use polyvinyl (elmers) or alaphatic (titebond) glue since it is not tolerent to heat and as a plastic, it creeps. I'm speaking as a Luthier, not a box builder though. Hide glue has a very long history and many pieces built with it are still holding strong after hundreds of years. only use hot hide glue that must be mixed and heated to no more than 145 deg/F. Any hotter and the collagen breaks down int geletin.
Who cares, right?

And hide glue is notorious for ingress and egress of moisture ( can be a good thing when disassembling a violin) and for spore growth of fungus etc...

As to the end grain swelling.. a simpler soulution
(though more work) is NO endgrain

One of the new plastics or aluminum would do the job.. and then you could also eliminate the foil

Another option for glue is the instrument glue offered by LMI and Allied Luthiers...

Unfortunately a mitered cut is all end grain. There is approx. 45% more surface area with a 45 deg. cut but you are gluing end grain to end grain. A weak joint as the glue is absorbed into the grain. Sealing the grain is highly reccomended. The beauty of vinyls and alaphatics is that all commercial guitar Mfgers use it and it keeps the $$$ flowing in my shop with a variety of repairs. Mostly neck resets and belly aches.
Applying a finish over a hide glue seam acts as a moisture barrier. Never had a fiddle in the shop that simply fell apart. I do use cyanoacrylate (Bob Smith Indust)for cracks and other similar repairs.

Craig

The original comment from someone about "end grain" was in reference to exposed end grain on the flappers


Sealing joints with something makes sense and is standard operating proceedure

A mitred joint without some sort of other fastening device .. mechanical or other wise.. has limited strength but infinitely better than an "unfortunate" butt joint
where end grain will eventual tear off the long grain of the other piece.. and of course allow moisture to enter the end grain even while intact..mitres have no "exposed" end grain..and that is why it is used..

Even with coating the joints prior to assembly there is no imperviable finish that will stop moisture..

Hmmm I have owned well over 100 guitars and a little over 50 mandolins

Many by commercial makers such as Gibson and Martin. With the exception of one absolutely brand spanking new D18S which had all the back braces popped off the day I received it.. never seen a glue failure..
I am certain it happens...

But ususally it isn't the glue it's the prep work or temperature or some other cause...

I prefer the LMI glue.. but I also use about 2 gallons of animal glue per year....

Curious.. you do neck resets as a result of glue failures ?

I have long thought that the typical dovetail neck joint was just **** silly and a hold over from violin
construction.. makes sense on a violin no sense on a guitar.. a formula for failure...

And I am sure the reason Collings and other makers use bolts..