Reed Going Flat

[Woodsman]

Possibly this has been raised before, but I didn't find it on a quick survey.

 

I bought an approx. 1895 48 button Lachenal EC last September. It has brass reeds. In general, I'm very happy with the feel and sound of the instrument, given that I can't justify paying thousands for something more upscale. I've been gradually wrapping my head around the EC fingering (I play accordion).

 

After about a month, one reed, the G2 (low G on the left side) went flat. Consulting with the seller, I filed it to tune, but soon it went flat again. After a few tries it would only hold the tuning for less than an hour. So the seller supplied me with a replacement reed. I got that in January--all great. It played fine until last week. Now the same reed is going flat again. Again I tuned it, but it's not holding. Why does it go flat, and why this one reed out of 96? What is the solution?

[Wolf Molkentin]

What is the solution?

 

I can't actually tell you - this is just to advise you not to apply more filing to that "poor" reed. You will have to solve the problem otherwise anyway, whereas a repeated (but needless in the end) loss of material will damage the reed irrevocably!

 

Besides - good luck with your crossing from the Piano (?) Accordion to the English Concertina - I hit that trail myself two years ago ...

Edited June 8, 2013 by blue eyed sailor

[Theo]

The classic symptom a a cracked reed is that it goes progressively flatter and flatter till it eventually breaks. The only solution is to replace the reed tongue, or the whole reed unit. It can happen with any reed, but brass reeds seem to be more susceptible.

[Wolf Molkentin]

The classic symptom a a cracked reed is that it goes progressively flatter and flatter till it eventually breaks. The only solution is to replace the reed tongue, or the whole reed unit. It can happen with any reed, but brass reeds seem to be more susceptible.

 

That's what came to my mind too - but Woodsman reported it to happen with the replacement reed as well!

 

Just strange coincidence?

[Guest mglamb]

.

Edited August 10, 2013 by mglamb

[Geoff Wooff]

It does sound like a "work hardened" brass reed tongue. In other devices it could be called Metal Fatigue and when you consider a 120 year old Lachenal Brass Reed... and in all honesty they were not the finnest thing when they were new...... and then you take the fact that the reed has probably been filed to bring it down from Old Philharmonic Pitch to modern A440hz ( a lowering of about half a Semitone)...

... you could be asking too much of it, perhaps ?

[Theo]

the reed has probably been filed to bring it down from Old Philharmonic Pitch to modern A440hz ( a lowering of about half a Semitone)...

 

 

Or perhaps more? What note name is stamped on the reed frame? If it is anything other than G it may have been tuned down even further.

[Wolf Molkentin]

 

the reed has probably been filed to bring it down from Old Philharmonic Pitch to modern A440hz ( a lowering of about half a Semitone)...

 

 

Or perhaps more? What note name is stamped on the reed frame? If it is anything other than G it may have been tuned down even further.

 

 

That's bright, Theo!

 

... and it might explain the rapid providing and failing ot the replacement reed...

[David Barnert]

I also was thinking "fractured reed" and the fact that it has happened twice does not make me reject the coincidence (as I can see no other explanation). ["When you have eliminated the impossible, what remains—however unlikely—must be the truth." —Sherlock Holmes]

 

What needs to be said in the above discussion (which is often said elsewhere) is that tuning reeds can be fraught with misadventure if attempted by the amateur.

Edited June 9, 2013 by David Barnert

[Woodsman]

Thanks for all your helpful comments. The diagnoses & solutions are mostly as I suspected. Metal fatigue was my assumption, once it continued to go flat. Neither the old nor the replacement (which is in all probability also an old reed) have any extra metal soldered on. The replacement is stamped with G. I can't recall whether the other one did--I sent it back when I got the replacement. This G is probably the most used note, as I'm playing lots of Celtic stuff, mostly in key of G or D. I have looked carefully and can't see signs of cracks etc.

 

Greg Jowaisas is sending me both a brass and a steel reed to replace this one. He has been extremely helpful. With his (on line) guidance I filed the old reed several times, just so I could continue to use it. But the time it would stay in tune got shorter and shorter--down to 1/2 hour.

 

It's great having all this expertise accessible through concertina.net

[SteveS]

... I filed the old reed several times, just so I could continue to use it. But the time it would stay in tune got shorter and shorter--down to 1/2 hour.

How exactly are you filing the reed?

An incorrect technique can seriously impair a reed and make it fail altogether.

Pictures of the reed after filing would be useful too.

Edited June 11, 2013 by SteveS

[Frank Edgley]

Something to keep in mind.....How aggressively are you playing? Some of us ask an awful lot of our instruments, pushing beyond what a normal concertina should have to bear. I find that people coming to the concertina from another instrument sometimes push & pull them to hard. Coming from an instrument like the piano, which has a greater range of dynamic possibilities than a concertina, the new player may try to emulate what he/she can do on the piano. Likewise, people coming from an inexpensive (under $1000) instrument are so used to the force needed to play them, often overplay the reeds, until they get used to the relative ease of a good Vintage or Hybrid concertina. Overstressing a brass reed is even more harmful than on a steel reed. Not saying that's what's happening, but something to keep in mind.

[d.elliott]

It does sound like a "work hardened" brass reed tongue. In other devices it could be called Metal Fatigue and when you consider a 120 year old Lachenal Brass Reed... and in all honesty they were not the finnest thing when they were new...... and then you take the fact that the reed has probably been filed to bring it down from Old Philharmonic Pitch to modern A440hz ( a lowering of about half a Semitone)...

... you could be asking too much of it, perhaps ?

 

As a thought, brass work hardens in cold forming, (is in initial manufacture) it then age hardens thereafter. the result is micro-cracking resulting in a loss of section and a stress raisers that culminate in crack growth through metal fatigue as the reed's cross section is reduced and its strength eroded then is goes flatter.

 

When I make reed tongues I cold forge the stock down to close to the working size to ensure a thorough and consistent hardening before shaping the reed and fitting it.

 

There are two distinct 'grades' of both Lachenal brass reeds, those fitted to the basic and so call tutor models, and those fitted to the premier models in the late 1800's. This is the same with Wheatstones. These higher grade brass reeds are beautifully crafted and so finely filed in manufacture that the chances of stressing are much reduced. Their responsiveness is high and tone superb. I would not dismiss all brass reeded instruments as sub-standard if I were you.

 

regards

 

Dave

[Theo]

I have looked carefully and can't see signs of cracks

Any crack that leads to the pitch dropping is usually invisible to the naked eye until the reed is well past the point of being in-playable.

 

Filing to bring the pitch back up will be at the tip of the reed, the crack will be further down the reed where the greatest flexing takes place, so it is very unlikely your filing has made matters worse.

[d.elliott]

The best way to confirm a crack is often to remove the reed assembly from the reed pan, then gently flex the reed whilst looking through the vent at the polished underside of the reed tongue, as you move the reed position you can see a discontinuity on the reflected light in the polished surface.

 

The cracking is intergranular in the brass's crystal matrix, as Theo says too fine to see, so what you are looking for is an indication of a location of a weakness caused by the crack, rather than the crack itself.

 

Dave