valve issues?

[scoopet]

i have about a dozen valves on my english concertina ,they are not quite covering the slot (maybe 1/2mm short).would this make the concertina use significantly more air on these notes? or am I being obsessive and should continue rather with looking for holes in the bellows with a smoking torch

When does one give in with airtightness?

[Frank Edgley]

I don't know which reeds you are referring to, but some of the very smallest reeds play better without valves. I suspect the valves in question are for smaller reeds and the person who installed them in this fashion may have done so because of playability issues.

[scoopet]

hi frank,

they're actually on the reeds around and just above middle c...(as an aside its an extended treble so I think the top 2 or 3 notes on each side look like they've never had valves)

[Geoff Wooff]

The valves should pass the ends of the slots by a small amount, ideally not too much but at least a millimetre.

 

If you have a high "Air Usage" issue it could be several other things;

 

Quality of the valve material.

Reed tongues set too high.

Felt gaskets giving too slack a fit of the reedpan in the bellows frames.

Warped end boards (action board, pallet board, which ever you wish to call it) or reedpans causing air to pass over the walls between reed chambers.

End bolts sunk into the end frames so that there is not enough thread length on the bolts to snug the ends down.

Reedpans that are sunk in so that the top surface of the chamber wall gaskets are below the level of the Bellows frames.

 

And then there are the usual Pads and Bellows leaks too.

[scoopet]

thanks geoff,

I'll check everything!

I roughed up the chamois leather on the end frames with a pin last night and that made a big difference.

cheers ,

simon

[scoopet]

well, as roughing up the gasket chamois made such a difference I thought i'd have a go at the chamois between the reeds.

there are no 'marks' on the bottom of the action board from the chamber walls so i thought over the top leakage might have been an issue so I have raised the reed pan by putting one layer of bushing felt on the top of the 6 corner supports under the reed frame at each end.

 

Its made a fantastic difference..thanks geoff!

 

shame i spent so long in the dark looking for holes in the bellows!

 

obviously( in hind sight!!) the bellows compression was good when not playing so I should have therefore discounted pads and bellows?

now I've just got to replace the valves and I have a very nice concertina ;and I've learnt some more concertina stuff

[Geoff Wooff]

I think that as you have 'roughed up the bellows gasket' and made a big difference, then you could make sure that the reedpans fit nice and firmly in the bellows.. even to the extent of lifting the Chamois gasket so as to fix a thin cardboard packing piece under the Chamois... as a guide the Pans should fit in such a way that it needs a little pull to ease them out... they should not drop out when you take off the ends.

 

This exactly the job I am doing on a concertina that is now airtight but runs out of air a little more quickly than I think it should.

As Chris Ghent says " Everything Matters".

 

Glad you are getting there with your's,

Geoff.