Making Replacement Reed Tongues By Hand

[Natasha]

I have a very old Klingenthal concertina by CGH I've been refurbishing. It has accordion-style German silver reeds on zinc plates and tuned to CG around A422. 

 

Some of the original reeds had broken or had cracks. It has been serviced before so some of the reeds had already been replaced with brass.

 

I could swap out the reeds and replace them with brass accordion reeds (which I have done, temporarily) but the original reed plates are stamped "CGH" so it's a shame to replace them. So I'd need to replace the tongues. Not worth paying to have them replaced so I thought I'd try making replacements by hand. 

 

I would have like to have used German silver, but I wasn't confident in how it may need to be hardened, if at all, so I played it safe and chose 0.5mm phosphor bronze sheet instead. 

 

I practiced first by making two reed tongues using a spare zinc plate I had. The second attempt was perfect so I decided to go ahead and replace this cracked reed

 

I filed off the rivet and removed the tongue. I then measured along it's length using vernier calipers to get an idea of the profile I'd be going for. 

 

I cut out a bit of bronze big enough for the reed tongue, punched a rivet hole into it using a hanner and panel pin, then attached the bronze to the zinc plate, and traced the shape of the slot onto the bronze. 

 

I then carrrrefully trimmed the shape out using tin snips. This took two attempts this time. It's good to trim it as close as possible since it saves on filing, but too close and it's ruined and you have to start again. This time I got within 0.2mm from the width I was aiming for. 

 

This is the most difficult part. Practice makes perfect. My first attempt when I was practicing was a complete mess. 

 

Then comes ALOT of filing. First I filed the edges so it was closer to the size of the slot. It doesn't have to be perfect yet because as I file in the profile, the metal "spreads" a bit so the edges are going to need to be filed again anyway. 

 

The rest of the filing I don't have pictures of since I had my hands full haha. Basically I held the bronze flat against another solid sheet of metal and held it tight with pliers. I then slowly filed away the surface with my tiny file until it is roughly the profile of the original reed.

 

I then bolted the reed back to the plate with a 0.4M bolt and nut. I didn't use rivets since I'd be taking it off and on again. I tested the reed in the concertina and it sang F#. I needed it to be tuned to E so back to filing. To lower the pitch, remove more material from the base of the reed, to raise the pitch remove material from closer to the tip. 

 

This whole process takes HOURS. If I had better tools or even power tools it would obviously be a lot faster. 

 

Eventually got it in tune. 

^^^German silver, brass, my phosphor bronze, and another German silver reed. 

 

It's as responsive as the other reeds and to my ears sounds exactly the same I found if the reed is too thick it won't be as responsive. 

 

This isn't exactly a tutorial. Just showing it's possible as long as you have basic tools and a lot of patience. Obviously don't risk this on an expensive concertina, but if you have a write-off, or one of these charming German concertinas, which I love, but makes no sense spending money on to professionally repair, then it's an option. 

[Natasha]

This was my first attempt haha

[Natasha]

Video demonstrating the reed. The valves need replacing as well. 

 

 

[Tiposx]

Good job, well done. The reeds tongues are the only part of concertinas that I have not worked on yet. I might give it a go after reading this - thanks!

[SIMON GABRIELOW]

Very interesting article, and yes, (as I know well myself)..you can achieve a lot with dedication and patience, and the most basic tools🌝

[RogerT]

Very interesting post thanks (I find the riveting back in position the hardest part of this process….a bolt is an interesting idea). So…for trad concertina reeds…..what is the process of removing and refitting the little screws and holder plate? 

[Natasha]

I haven't tried with traditional concertina reeds so I really don't know!

[Tiposx]

Roger

It is most likely that the screws will shear rather than screw out. If they come out ok they might be damaged, and might be difficult to source, I don’t know.

I have repaired a couple of brass reed shoes by drilling the screw holes out and tapping them to M2.5. Then filling the holes with the end of a brass M 2.5 screw, secured with Loctite. Mill flush, then drilled and tapped for stainless steel 10BA screws. It looked like a sound repair but I didn’t see them with reeds fitted.

[Tiposx]

[Tiposx]

I am having a bit of trouble with the technology (and my memory) 3 reeds that I repaired this way were installed  successfully and are playing well at the moment. Two of the reeds were small steel ones on an ec  (ignore the brass piece of reed in the photo), the big brass one was on an anglo. I will try again to upload a photo of that reed plate later.

Edited November 21 by Tiposx
Memory returning!

[Tiposx]

This is the largest reed showing the new screws

[alex_holden]

17 hours ago, Tiposx said:

It is most likely that the screws will shear rather than screw out. If they come out ok they might be damaged, and might be difficult to source, I don’t know.

 

When I've had trouble with seized clamp screws in the past, I was able to get them out by heating the frame with a blowtorch and quenching in water. After a couple of thermal cycles the screws came loose easily. This will of course ruin the temper in the reed tongue, but I was going to replace it anyway.

[RogerT]

V interesting (again) ..and Tiposx …I'll reply to you. But these 'tina reed screws were put in and not intended for removal….anyone know what the process was? How come they are effectively seized in place? How was this done?

[alex_holden]

24 minutes ago, RogerT said:

But these 'tina reed screws were put in and not intended for removal….anyone know what the process was? How come they are effectively seized in place? How was this done?

It’s just decades of rust. They would have been easily removable when new. 

[Tiposx]

The ones that I repaired had been sheared by someone previously. I guess that they had corroded- mild steel in brass plus a little moisture. They were well stuck in, and didn’t turn at all whilst drilling the core out. The photos show that on the small reeds only one screw had stuck on each plate. So is is quite random.

[Clive Thorne]

I imaging that soaking the whole reed plate in a light penetrating oil (eg plus gas) for a few days might help when removing the screws.

[wschruba]

On 11/22/2024 at 1:51 AM, alex_holden said:

 

When I've had trouble with seized clamp screws in the past, I was able to get them out by heating the frame with a blowtorch and quenching in water. After a couple of thermal cycles the screws came loose easily. This will of course ruin the temper in the reed tongue, but I was going to replace it anyway.

 

You might find some luck with a soldering iron (75w would be faster, but 40 works, too) for more precise heating/cooling.

 

I have used them on piano actions with some positive results, but then, most of the screws are going into wood on those; the soldering iron method works phenomenally well with screws in wood.

 

For metal stuff, you can use a shock penetrant (CRC makes something called "Freeze Off" in North America), followed by a heating cycle with an iron.