“Junk” accordion bellows for DIY tuning table - fix busted corner with tape?

[AlicePalace]

Hello, helpful people. I picked up a cheap, beat up old Hohner Carmen yesterday with the intention to (a) use the bellows in a DIY tuning table, and (b) practice repairs on it. I’ve poked around inside and have removed the bellows, and I note there’s a big-ol’ hole in one of the bellows corners (picture attached, you can see light shining thru). Just thought I’d check with y’all to make sure it’s okay for me to just slap some duct tape (or something) on it because it’s just going into a tuning table. Yes?

I find it interesting that the reeds themselves (not the leathers, not the wax, just the reeds) seem in better shape than the (somewhat rusty) ones in the Larenti accordion I’m trying to fix up. It shows how much of a difference it makes to store accordions in a dry vs. wet environment. The wax has given up and there were three detached reeds just free-riding around the bass compartment (one is missing a leather valve, and I don’t know where that has gotten to), along with a mysterious, triangular piece of paper. This will give me some good practice for waxing reeds back on. I appreciate the fact that Hohner marked the outer side of the reed with a T so it’s easy to know which way to attach it.

Anyway, TIA for your advice on the bellows.

 

[debra]

If you want to make a generally usable tuning table you will need larger bellows. The treble side has reed blocks that protrude into the bellows, at least somewhere (typically at the lower notes) and the bass side has reed blocks that protrude into the bellows everywhere. The tuning bellows need to be large enough to accommodate the protruding reed blocks. (I'm assuming you are building a proper tuning table, not just a table for checking the voicing and valves of a single note.
When the tuning bellows are large enough you may need to also have a smaller cover for smaller accordions.
The proper fix for the corner is thin (goat) leather on the inside and a metal corner piece on the outside. Anything else is a temporary "stop gap" measure at best.
The T on the reeds is an indicator of the type of reeds. T reeds are trapezoid, with a rectangular wall between the two reed tongues. There are also H reeds. Italian reeds mark one side of the reed plate with one or more diagonal stripes.

 

[AlicePalace]

Thanks for your input, Paul. My idea was to just make the voicing/valve check sort of table, but if it turns out these bellows are wide enough to accommodate my two small accordions, I suppose I could consider making a “proper” tuning table that would actually help me with whatever tuning I might need to do. I’m not sure I’ve ever seen a proper tuning table — seems like everything I’ve seen on YouTube and elsewhere is just for checking single reeds.

Thanks for the info about the T mark on the reeds. I’ve learned something new today and this will give me something to look for on my other accordions.

 

[boxplayer4000]

AlicePalace:

It sounds like the tuning bellows Debra describes is the type where the treble end of the accordion, with the reed banks in place, is placed over the tuning bellows. The type you envisage, I think, is the type where the removed reed blocks alone are placed on the tuning table and each reed listened to individually.
I had a ’spare’ set of bellows (and some spare time) and made the tuning bellows in the picture below. I prefer to have three holes cut for the reeds so that I can listen to a 3 note musette. The bellows used are only 13” long and the top measures 12” x 24” so accommodates any reed block with ease. The fitted reed blocks in some accordions protrude ‘out’ of the accordion beyond the edge where the bellows are fitted so that the assembled accordion treble end cannot be laid on the tuning table top to listen to the assembled instrument. In this case a simple collar of wood/felt/foam can be made to lift the reeds clear of the table.
Hohner started manufacturing ’T’ reeds in the 1930s. No doubt changes have been made to their manufacture but they are still available for sale today. They are all still pretty good for replacements in many situations and you have a good supply of ’spares’ there in your Carmen.
The hole you have in the Carmen bellows will require suitable leather and a metal corner to repair. It may not be a top class repair but will be perfectly adequate in a tuning bellows situation.
If you decide to make tuning bellows I recommend you use marine quality plywood along with a good varnish.

 

[AlicePalace]

The type you envisage, I think, is the type where the removed reed blocks alone are placed on the tuning table and each reed listened to individually.

Thank you so much for your response. Yes, this is what I was planning, as I didn’t even know the other type existed. I do have a question: How did you attach the bellows to the wood?

 

[boxplayer4000]

The wood is fixed to the bellows with glue and screws.
It can be helpful to be able to blow the reed(s) both as detached/removed reed blocks on the table as well as when the reed blocks are in position in the treble end. The pitch normally changes slightly when going from one position to the other. ie. the pitch (normally) rises when the reed blocks are removed from the more constrained position inside the treble end.

 

[AlicePalace]

The wood is fixed to the bellows with glue and screws.
It can be helpful to be able to blow the reed(s) both as detached/removed reed blocks on the table as well as when the reed blocks are in position in the treble end. The pitch normally changes slightly when going from one position to the other. ie. the pitch (normally) rises when the reed blocks are removed from the more constrained position inside the treble end.

I have read about the pitch issue and was wondering how people managed to tune (and check) while the reeds were still in position. I wish there was a video of this. All I’ve found are people doing tuning with the reed blocks removed (along with comments about how this is not the way to do it properly)

 

[boxplayer4000]

I have read about the pitch issue and was wondering how people managed to tune (and check) while the reeds were still in position. I wish there was a video of this. All I’ve found are people doing tuning with the reed blocks removed (along with comments about how this is not the way to do it properly)

It's quite possible to tune many of the reeds 'in position' if you have the tools and skills; even the 'inside' reed. There are videos showing this being done. Try YouTube. Thierry Benetoux has a fine book on accordion repair. The translation from French has some weaknesses but you can usually catch the meaning. Here he is:

 

[AlicePalace]

It's quite possible to tune many of the reeds 'in position' if you have the tools and skills; even the 'inside' reed. There are videos showing this being done. Try YouTube. Thierry Benetoux has a fine book on accordion repair. The translation from French has some weaknesses but you can usually catch the meaning. Here he is:

Thank you for the picture. It’s helpful to have a visual. I believe I have the right tools, as I purchased a reed tuning tool kit from ErnestDeffner.com — it has a reed ”plucker” (shim), 2 reed scratchers and 2 reed ”lifters” (curved hooks). I will have to watch the videos and practice with the hooks, as those are tricky. I’ll also look for the book you mentioned, if you think it offers more than accordionrevival.com.

I do know that I have to be very, very careful with the smallest reeds, and that these can snap if they’re not handled delicately. So I’ll be leaving those alone unless I absolutely have to tune/voice them.

 

[boxplayer4000]

It sounds like you have the start of a good tuning tool set there. As a reed should always be supported while it is scratched or filed perhaps you need something to support the inner reed while the reed block is on the table. A simple metal bar to place underneath it while you lower it and a wire to lift (and support) the reed tongue out of its slot while you raise it will help if you don’t already have them. (See diags. below)
You describe two ‘curved hooks’ and wonder if these are the hooks to lift and support the inner reed while the reed block is fitted in position in the treble end. (I’m sure Mr Thierry Benetoux will have a reed lifting hook lying nearby in the photo above). It’s an acquired skill but not as difficult as it might sound ie. the hook is inserted under the outer reed and twisted round to get underneath the inner reed and lift/support it. You are fortunate in having the old Carmen accordion with a good supply of reeds to practice on.
The smallest reeds are best dealt with with a thin strip of sand paper/emery cloth stuck to a thin spatula type device to make your own ‘file’ and is a less aggressive method of adjusting those more delicate reeds.
Thierry Benetoux’s book is called ‘The Ins and Outs of the Accordion’. It tackles accordion problems in a methodical manner ie. if (x, y or z) is the problem then the following items may the answer and by a sort of ‘critical path’ method narrows down the answer to focus on the problem and explains how it should be rectified. The author of ‘Accordion Revival’ refers to Thierry Benetoux’s explanation of musette tuning in his approach. However to understand Thierry Benetoux’s explanation a good understanding of the physics of sound is required ie. in particular the relationship between Hertz (frequency), Beats per Minute (B.P.M.) and Cents (a semi-tone divided into 100 parts). An appreciation of what an exponential curve is also helps. However I’m aware that many good tuners are not into the physics of the situation at all and I think, at the end of the day, it is an art rather than a science.

 

[AlicePalace]

You describe two ‘curved hooks’ and wonder if these are the hooks to lift and support the inner reed while the reed block is fitted in position in the treble end.

Here’s a picture of what was included in the tool kit. I’m sure you’re right, that the hooks are for lifting and supporting the inner reed while the reed block is fitted in position. I’ll have to practice that on the Hohner.

As for tuning, I’ve been reading up on the physics of it so I understand it better. I’m a lifelong musician and am good with math and science, so I figure I will be able to grasp the concepts and techniques, and will be very careful not to screw things up. I know I will not be using a Dremel, that’s for sure!

 

[jollyrogeraccordions]

So, here is a video to demonstrate how to use a hook to get at the inside reeds. Please note that for accurate tuning the reeds should be tuned inside the instrument as the pitch tends to alter once the block gets inside the casing. Although in point of fact if you have the concert/reference reed correctly pitched, you can successfully set the tremolo reed like this, which can save a fair bit of time.

 

[AlicePalace]

Oh my gosh, that video is so helpful. Thank you so much! It seems to me it would take quite a lot more time to tune with the reeds in place in the instrument, because you have to keep flipping the treble end, putting it on the tuning box to check the tuning, then if the tuning needs more tweaking you’d have to lift it off, put it in a stand (??), file as appropriate, put it back on the tuning box, etc., is this correct? I mean, that’s not a reason to avoid it, but I think it means it’s a lengthier process, and one would also need to know which reeds correspond to which keys on the keyboard. What do people do for this — make a diagram? That’s what I figure I would need to do.

 

[Ventura]

well, i am very imperfect.. so
yes, i first make a diagram/chart of every note deviation in and out
(last years deskpad monthly calendar flipped over is just the right size)
this gives a good overall understanding of how the tuning sits in the
grand scheme of things

i also have very good tuning machines with wide sweeping needles
(analog and digital) side by side to compare)

therefore, the noted "deviation" is my target, not the actual frequency
when the reed is over my air-pump driven tuning table

if i can successfully adjust the reed to offset the noted deviation,
then oftentimes once back in the accordion it is good enough, or
only needs a bit more tweaking

for myself, i am not usually worried about tuning to perfection, as
i kind of feel slight imperfections are part of an accordions personality,
so as long as a box is in tune with "itself" relatively speaking, i am happy

of course i am not ever tuning someone else's accordion.. just my own

 

[AlicePalace]

i also have very good tuning machines with wide sweeping needles

Which tuners do you use? I just have a free app at the moment (and there’s plenty of time for me to find something else to use, as I’m nowhere close to doing any tuning quite yet)

 

[JerryPH]

Dirk's Accordion Tuner software is considered the pinnacle of applications for tuning accordions... but it is not cheap and it is difficult to get loaded on to another or computer if that one dies.

They have a nice "how-to" on YouTube:


You will note that the tuner in this video uses a dremel tool... kind of a big no-no to professional tuners as it can do a lot of damage in an instant quite easily. Files are considered the defacto standard to do that task safely but it does take a bit more time.

One thing that they explain, but NOT clearly is that they "test" the accordion with everything in place, measure all deviations, document it precisely and adjust for the deviation amount off when tuning. They do NOT tune for proper pitch when the reed block or the reed is out of the accordion.

A YouTube search for "accordion tuning" should give you a few good results.

I think that I will want to also start on this sometime soon... I have a couple of accordions that would benefit from getting some attention.

 

[EMan]

Here is the "table" that I built to listen to individual reeds. It's not pretty, but it works. Note I replaced ( not very well) the corners of the worst leak offenders on the bellows. I live in Florida so there is much humidity and it shows on the outside of the bellows. I can put a reed block on the top and "sound" any reed I choose. Serves my purpose. It's also easily moveable, since it's self-contained, so I can pick the entire unit up and move it off my bench.

 

[AlicePalace]

Here is the "table" that I built to listen to individual reeds. It's not pretty, but it works. Note I replaced ( not very well) the corners of the worst leak offenders on the bellows. I live in Florida so there is much humidity and it shows on the outside of the bellows. I can put a reed block on the top and "sound" any reed I choose. Serves my purpose. It's also easily moveable, since it's self-contained, so I can pick the entire unit up and move it off my bench.

Very nice! A forum member was kind enough to reach out and send me a few corners to try out, and I found one with the right radius (thought the “arms“ are too long). So my repair looks a lot like yours. Thank you for sharing some pics of your design. This is what I’m planning to make — something where I can test each block. I realize I can’t do a full tuning on something like this, but I’ll figure that out if/when I need to. Thanks!

 

[Ikesaccordions]

How I tune:
First off my tuning bellows are crude. Two pieces of plywood with leather facing on one side with holes to put the reedblock over. The holes not in use are covered with a strip of masking tape.
The bellows are removed from the wooden frame pried off with an old meat cleaver. The edges of the bellows are glued to prevent air leaks, and any hole in the bellows is fixed with duct tape.
How I compensate for having such a crude tuning bellows is using excellent tuning software; in my case there is a strobe emulator and a frequency readout, high grade microphone and pre-amp, and audio module plugged in to the USB jack in series with all the stuff.
I can see the pitch change with air pressure using the strobe emulator. There is automatic pitch detection, and a cents deviation readout. The best steel files are from Jewelry supply, or diamond coated, and for shims to protect the aperture, I make them from flat metal stock, or I use car valve lifters for adjusting tip clearace ( can 't remember what they are called). For piccolo reeds, I take the metal shim out of the thing that makes the store alarm go off when you go out the door whether you paid or not. These can also be used to check if a reed is off-center.
The lower piece of plywood is clamped to a wooden parson's table on top of the workbench, so I can work standing. I can lay the mic there. The pre-amp has a bias voltage for these fancy mics.
Flat reed lifters are better than round to keep from twisting the raised reed from inside the block. Sometimes if a rapid pitch change is needed I have small sticks I bought with sandpaper on them. I have mounted diamond burrs on a dowel handle including a pointed one for the underside of a lifted reed. The hooks shown in the picture are best used to lift reeds in non-removable reed blocks. A reed scratcher can be made by snapping off the tip of even an inferior steel needle file.
The software 12-tone basis can be set to Equal Temperament or several historical Temperaments or user-defined. The standard pitch can be A440, or changed to match the accordion's like A442 or A438 etc.
The tip of the reed must ordinarily rise above the aperture about the distance of the reed thickness, and this can be also checked by ear by varying the bellows air pressure.

 

[Dingo40]

You will note that the tuner in this video uses a dremel tool..

The sound of the dremel reminds me of my recent visit to the dentist!