wunks

I should let this go but I can't. I'm proposing a tough but flexible plug ( leather has a thickness after all ) with the slightest feathering before cure atop and beneath. Not a patch, ( although perhaps in conjunction with one ). Tried and true works but there's more than one way to skin a cat.

True, certainly but if the alternative is to toss 'em and buy a new set a bit of experimentation wouldn't hurt. That's why I made the disclaimer in the first place. The concertina world isn't divided sharply into Experts and Dolts. Cheers

My friend Joel (passed ) had a very small bandoneon I always envied. It was about the size of a standard 'tina, all the beautiful workmanship, pearl button tops and such and yes, a bandoneon.

I've posted about this a couple of times but I'd like to mention that a slice of refrigerator magnet about one third of the reed length will lower the pitch a whole step. easy to do, easy to reverse, easy to experiment. Stays put.

" Shirly " this has been posted before?

Perhaps not but the flex/fill/adhesive properties should allow for a plug contiguous with the leather edges with little or no overlap at least externally and maybe a brief thin film on the inside to anchor. A future leather patch needn't reverse anything. At any rate:

Not a fettler but these corner breaches appear to be caused by wear rather than flex. I would be tempted to apply a flexible adhesive such as Goop Marine Sealant/Adhesive or shoe goo very sparingly from the inside and pressed out to be just barely proud of the corner then hand dressed with a small tool such as a flux brush inside and out. The patch could be easily color matched with a dry powder. The above appear to be silicone based. There is a latex based alternative specifically for fabrics and leather. The product I have is called Tear Mender. I'd try this before springing for a new bellows....

I may help if you "engineer" your play so that you're starting each phrase with the bellows completely closed or open. Assuming you have an air button you can play with a "controlled leak" to achieve this.

One thing you can do to smooth out your playing is learn how to switch fingers on a note without interrupting the reed thereby re-positioning your hand and avoiding a "hop" to reach a subsequent note or harmony shape. It doesn't involve a bellows change but smoothing out in general may make those more tolerable.

It sounds to me like you're trying too hard to impose your will on the instrument. As a duet player, I've yet to encounter a "phrase" that wouldn't be improved by or at least tolerate a bellows change here and there. Limitations are the source of creativity.

Hopefully all this is of use to the OP ( Perhaps in the future? ). From observation, I would figure it this way to start then adjust: If one third of the reed length for a given card thickness yields 2 semitones, adding a half piece ( at the tip? ) should be close to 3 semi's. Zero it in by clipping the small piece or perhaps sliding it up or down. I'd be interested to know if anyone tries this. Cheers

Yes. That's why I said 1/2 not more but I'm an intuitive tinkerer. One could use thicker card stock instead or piggyback. if I recall, some cards seemed too thin. It's easy enough to experiment. I'm sure some here could do the calculations but for me, if it sounds right it is right......😊

There is an easy way to do this that I posted awhile back. It was met with some skepticism but I can say now after several months of play that it works very well. I cut a piece of magnetic card stock ( 'fridge magnet ) about 1/3 the length of the reed and just slightly narrower. This was to lower one low cello F reed of the pair to Eb. No buzz or other problems to date. Totally reversible. For three semitones I would start with half the reed length and clip to adjust. I was lucky with my first guess.

I already have 5 thumbs on each hand....😏

Although the Jeffries Duet is even rarer than the others and is generally priced above your budget it's worth mentioning Gary Coover's Tutor with arrangements for this instrument.