Reed Intermittently Not Starting

[varney]

The low A on the left hand side of my lachenal anglo ( i.e. fifth button down on inside row ) has been giving me trouble. When I draw the note on its own it's fine but when I try to do it in combination with another note ( usually the B top button, centre row, right hand side ) it won't start or starts late ( almost when bellows is fully expanded ).

 

After I've tried this a couple of times the reed won't sound at all until I press and draw it in combination with another adjacent low note and then it rights itself and plays okay on its own until I try it in combination with the B again. I've cleaned the reed and put a new valve in.... anyone got any other suggestions?

 

Thanks...

Michael

[Greg Jowaisas]

Check the set (distance) of the reed above the reed shoe. Compare to a similar pitch reed whose response you like (usually 1&1/2 Xs the reed's thickness is a good place to begin). If it starts OK on its own but not with other reeds (diminished air supply) chances are the set is too high. I use a small dowell/stick with a tapered end to push on the tongue. Take your time resetting the reed. Better to gradually approach where you want the set than to slip or over due it and stress the steel.

 

Centering of the tongue in the reed frame can also affect reed effeciency.

 

Greg

 

PS If you don't already have it, Dave Elliott's Concertina Maintenance Manuel is invaluable.

[varney]

Thanks Greg.........I have Dave's book and in his reed fault finding section there are two descriptions which seem to cover the problem I'm having:

REed stalls on initial button press or if playing loudly

or

Reed is slow to speak or 'breathy'

 

Both are caused by the gap between the tongue tip and the frame being too small. The suggestion is to tension the tongue by pushing it down with a wooden probe.

 

I tried pushing the reed tongue tip back through its slot a couple of times but am unsure how often to do this or by how much it needs to be depressed. The suggestion is to do it 'several' times, but I just wanted to check with people here in case I bend the bloody thing completely out of shape!

 

After I've tensioned the tongue do I have to put it back in the reed pan and bolt the end back on to check it, or is there a way to do this outside the instrument?

[varney]

Hey Presto! After posting my last I took the reed out again ( it's actually the low B - not A as I mistakenly said earlier ) and gave it a few more delicate pushes down through the frame, replaced it and it's now playing every time....

Thanks for the help, Greg..

 

Michael

[Greg Jowaisas]

"Good fer yuh," Michael!

In many instances it does not take much of a push to change a reed set just enough to get it working properly. The distances involved are small, measured in thousandths of an inch where the tip of the reed tongue clears the shoe.

 

The "rub" in describing how much is enough is that every tongue is different depending on the steel (brass is whole different animal), how long and thick the tongue is and the individual response of the reed. There is no substitute for experience. Carelessness and inattention can make things worse rather than better very quickly.

 

I recently worked on what should have been a nice 36b Lachenal that was playing poorly. A number of factors contributed to its lackluster performance, and in particular very poor reed set. Whoever had "fiddled" with the instrument previously did not understand how these reeds should be set to get the most out of this particular instrument. Some reeds would start fine, some would be breathy and some stalled and all at the same playing presssure. Volume and timbre were all over the board. With new valves, matched to the reeds and properly installed, and the right reed set and a thorough tuning it played to its full potential. The owner was delighted.

 

Best of luck getting your Lachenal to play its best. I used to read and reread the Elliott book (and still do) before going to bed. Sometimes a solution to a problem would appear by morning! Repairs take time and care and, as Dave would remind us all, "proper preparation".

 

Greg

[Dirge]

Presumably where you push on the reed affects the way the shape changes. I only touch my reeds with great trepidation but I have tweaked a couple and push close to the clamp; that would set it only at that end, hinging the whole thing about the clamp, in effect, whereas heaving on the free end would tend to change the bow of the whole thing would it not?

 

My technique came about purely because it seemed much more controllable (and effective), but should I worry about this aspect? Is there a right and wrong way to do this fine setting?

[Greg Jowaisas]

As per the diagrams in the Elliott book longer and heavier reeds sometimes benefit from having more of their surface above the shoe. Kind of a plateau effect. Pushing more toward the middle of the reed while holding down the tip can accomplish this. Smaller, shorter reeds need little or no tip showing. Medium reeds usually benefit by an adjustment at the tip or halfway back.

 

I would caution that experimentation and learning to set reeds on a good instrument is not the best idea. However, carefully observing the set of a similar reed that performs well can give clues on how to set a misbehaving single reed.

 

Greg

 

PS. After tuning an instrument I spend hours getting the reed set right. As far as I know there are no shortcuts. It take a lot of playing, making notes, unbolting the end, adjusting reeds, bolting things back together and trying the instrument again. Then repeat, repeat, repeat until everything is just right. Not a process for the impatient.

[Dirge]

Thanks for that Greg; I'm comforted to find even experts can't do it quickly.

[varney]

And as if to chime in with Greg's incantation of try, try again I found this morning the low B reed has resumed its stalling! I guess whatever reshaping my tinkering cause went and straightened out overnight and now it's acting exactly the same as before.

 

It would certainly be handy if there was a way to test the reed 'in the air' so to speak. If not, and it means bolting and unbolting the ends, then I'll soldier on in hopes of resolving the problem....

 

Michael.

[Ransom]

Re-gapping reeds is something harmonica players do, to. I wonder: if you buy a thirty-dollar harmonica and gap all the reeds to Christmas and back, does it teach you anything about gapping concertina reeds?

[Greg Jowaisas]

In the workshop, on a tuning jig, it is possible to carefully listen to a reed's response before and after changing the set.

 

Without a jig you could also cup your hand holding the reed between the thumb and your index (sometimes curling the index) to make a seal and be able to sound the reed in your hand by holding your lips close and blowing on it. It takes practice but after awhile you can hear and feel the reed's response.

 

Another method might be to have some shimstock, say .0005, which is a good thickness to place under the reed tongue while tuning and use that shimstock like a feeler gauge. How tight or loose the shimstock fits under the tongue will give you an idea of how far you have moved the set.

 

All the above does not negate the necessity of finally putting the reed back in the instrument and evaluating its response in the instrument. At which point you might begin the process again....

 

I don't want to discourage anyone from doing basic maintenance on their instrument. I think everyone should know how to competently open up their concertina to clear a reed, or replace a valve or a spring. But setting reeds as well as tuning and some aspects of action adjustment, fret work repair and replacement and refinishing take practice and a certain attitude/aptitude. If you are careful and deliberate and willing to practice you can probably learn to do some or all of these things. Having the proper tools doesn't hurt a bit.

 

But if you'd rather spend your time playing your concertina, or if you are prone to impatience or carelessness and not used to working in the perimeters of one thousandth of an inch please don't compromise your instrument. Call in experienced hands or a professional.

 

Greg

 

PS. Gaping reeds on a harmonica might be one way to practice and gain a feel for reed response and set. I'm not sure how much of this would directly transfer to english construction concertinas where the shoes are individual and the tongue is so much larger.

Edited March 22, 2010 by Greg Jowaisas

[Dana Johnson]

And as if to chime in with Greg's incantation of try, try again I found this morning the low B reed has resumed its stalling! I guess whatever reshaping my tinkering cause went and straightened out overnight and now it's acting exactly the same as before.

 

It would certainly be handy if there was a way to test the reed 'in the air' so to speak. If not, and it means bolting and unbolting the ends, then I'll soldier on in hopes of resolving the problem....

 

Michael.

If you actually changed the reed the last time, I would doubt very much that it has gone back to where it was. While there may be a "set" issue with the reed solved or otherwise, it is sounding like something else may be at work if it is up to it's old tricks. If after removing and replacing the reed frame in the instrument it worked for a while, I would suspect the frame may have been slightly lose and the replacing of it put it tight until it vibrated itself slightly lose again. Reeds tend to make a shallow frame length dent in the side of the dovetail from the expansion and contraction of the wood against the incompressible frame, The frame will gravitate to this area on it's own, though it may be a slightly tighter fit a little less or farther in. A lose frame will rob the reed of needed energy and slow the response, ( or keep a poorly set or reed with bad clearances from sounding at all ). People usually resort to thin paper shims as mentioned dozens of places ( best described by Greg ) in similar threads here to cope with these permanent changes in the dovetail slots. The problem is often seasonal ( worst in the dry time of the year ) but eventually may become full time.

 

Reeds do reset themselves sometimes in response to residual stresses or very hard playing, but I think it highly unlikely in your case and so soon. Valves that have lost their springiness and tend to remain open after a note is played ( the note in the opposite direction in the same chamber ) can also allow too much bypass air especially in low notes for the reed for the other bellows direction to start quickly or play at all, especially if they are staying so high that the vacuum of air going by the valve isn't enough to pull it down. Curled valves are the worst for this in my experience since they can actually resist closing.

Dana