Jump to content


Photo

Valves


  • Please log in to reply
26 replies to this topic

#1 Geoff Wooff

Geoff Wooff

    Heavyweight Boxer

  • Members
  • PipPipPipPipPip
  • 2099 posts
  • Gender:Male
  • Location:France

Posted 14 August 2012 - 12:03 PM

I would like people's opinions on Valves.

For instance, when a note is not sounding well and you have tried several things to improve that to little avail but there is no noticeable valve slap or fuzzing sounds that could be attributed to a valve problem but you decide to change the valve to see if an improvement can be achieved, would you try a valve of different thickness/stiffness ? Or perhaps, like myself, you would just do a 'suck it and see' method... "try another valve maybe that will do it".

#2 malcolmbebb

malcolmbebb

    Chatty concertinist

  • Members
  • PipPipPipPip
  • 398 posts
  • Gender:Male
  • Location:Dorset UK

Posted 14 August 2012 - 12:24 PM

Could you simply hold one valve open (and t'other closed) using tape or something more elegant, and see if that improves matters?
I would think that would confirm or eliminate the valves as the source of your problems.

#3 Chris Ghent

Chris Ghent

    Heavyweight Boxer

  • Members
  • PipPipPipPipPip
  • 1058 posts
  • Gender:Male
  • Location:Blue Mountains NSW

Posted 14 August 2012 - 08:22 PM

Geoff, how is it going, was thinking of you last week, one year since the trip to Chateau d'Ars.

One of these days someone is going to come up with a synthetic valve which is a constant and therefore predictable item. Until that day assessing the worth of a valve is going to remain the black art. I have never seen anything written about valves that has been the slightest bit useful. I have also not achieved a position of, that leather came from the same source and is the same thickness as the last therefore it will act the same.

I would certainly countenance a new valve of the same apparent value because some valves just don't work very well, whether it is just in that particular position or in any position I don't know because I don't reuse them.

I might fit a lighter valve if I thought the reed was sounding a little muted, either in volume (check the set first) or in tone as in lacking tops. I might fit a heavier valve if I thought the reed sounded a little whistley (is that a word? I'm referring to a tiny sibillance), though I might try using a narrower valve of the same value first so as to try to decouple the valve from the action of the reed beside it. In lieu of a lighter valve you can sometimes fit one of the same value and move the glue point back further away from the slot. This allows the leather to bend over a longer arc, taking less force. Another thing you can do is again to trim the valve to be narrower or to taper towards the tip.

I generally use the lightest valve I can that does not couple with the reed beside. This makes the concertina as fast, loud and bright as it can be. If you were using it for singing you might prefer a slightly heavier valve. If you are working to time constraints the temptation is to over valve the instrument as you will have fewer problems, but then you will not get the best out of it.

If I am not sure as to whether there is a valve problem I sometimes remove the opposing valve and try without it. If it is a little light and verging on whistley I will try removing the valve beside. This is not too different from Malcolm's suggestion.

Looking back on this I realise the term heavier and lighter look like they refer to thickness, while they probably do, the wish to return power of the valve is part of the equation. When you pick up a valve and finger it you always feel its wish to return.

I have occasionally tried to dream up a noiseless frictionless and instant mechanical valve but I always wake up after I have it working and before I see how I did it. Anyway, where would life be without some doubt and uncertainty?

#4 Geoff Wooff

Geoff Wooff

    Heavyweight Boxer

  • Members
  • PipPipPipPipPip
  • 2099 posts
  • Gender:Male
  • Location:France

Posted 15 August 2012 - 01:50 PM

Malcolmbebb,
yes thanks for that point and well taken... some ways to eliminate the possible causes of problems are the starting positions for sure.


Chris,
we are fine here and we hope all is good at your end.

Many thanks for your insights on Valves and plenty of good info there for getting my 'new' concertina to agree with itself.

Fondly remembering your visit last year,
Geoff.

#5 Geoff Wooff

Geoff Wooff

    Heavyweight Boxer

  • Members
  • PipPipPipPipPip
  • 2099 posts
  • Gender:Male
  • Location:France

Posted 16 August 2012 - 09:34 AM

Well,
I have now changed the valves on the offending note ( low F bellow the Bass stave) and the sound has improved greatly. The valves that were there were almost 2mm thick and very soft and fluffy on the underside so the sound waves coming off the reeds were hitting a hairy carpet! The new valves are of a much denser texture and about half the thickness. Also I used the minimum length of valve and trimmed the end down due to space constraints caused by having a large F reed in the chamber designed for a G#.

So by the time I have replaced all the valves, and most are perhaps the original 90 year old ones, I think the new baby will please me.

Thanks again lads!

Geoff. :)

#6 Chris Ghent

Chris Ghent

    Heavyweight Boxer

  • Members
  • PipPipPipPipPip
  • 1058 posts
  • Gender:Male
  • Location:Blue Mountains NSW

Posted 16 August 2012 - 07:03 PM

I didn't mention low valves, they are the ones that suffer from dying reed pulse syndrome. This is where the valve is being closed by the bellows being reversed with the button being held down. Although the valve closes, stopping the reed swinging, it does not stop instantly. The dying reed swings have enough air pressure to unseat the valve a few times leading to a nasty ttzz noise between the notes. Only large reeds create enough pressure to do this. A valve in this situation needs a little more "wish to return" force. Some accordions use a small leaf spring lying along the valve to help with this. Increasing the wish to return pressure means the note is a little harder to play but I know of no other way around it.

#7 alex_holden

alex_holden

    Heavyweight Boxer

  • Members
  • PipPipPipPipPip
  • 580 posts
  • Gender:Male
  • Location:Lancashire

Posted 31 May 2017 - 12:14 AM

I didn't mention low valves, they are the ones that suffer from dying reed pulse syndrome. This is where the valve is being closed by the bellows being reversed with the button being held down. Although the valve closes, stopping the reed swinging, it does not stop instantly. The dying reed swings have enough air pressure to unseat the valve a few times leading to a nasty ttzz noise between the notes. Only large reeds create enough pressure to do this. A valve in this situation needs a little more "wish to return" force. Some accordions use a small leaf spring lying along the valve to help with this. Increasing the wish to return pressure means the note is a little harder to play but I know of no other way around it.


I'm getting this effect on the bottom few notes of my first instrument (a duet with trad reeds). I bought the valves from a parts supplier because I haven't yet found the right sort of leather to cut my own. They don't seem to have much 'wish to return' as you put it. Any suggestions on what I can do to improve them?

#8 Chris Ghent

Chris Ghent

    Heavyweight Boxer

  • Members
  • PipPipPipPipPip
  • 1058 posts
  • Gender:Male
  • Location:Blue Mountains NSW

Posted 31 May 2017 - 02:59 AM

Without seeing and feeling them it is hard to say. You could try wetting them and then ironing them dry before use; this should stiffen them. 

 

Two identical looking and feeling valves can both work or only one work or neither. It can be frustrating when you find the right valve but don't know why it was better than the one before. I bought a few valves from a parts supplier a few years ago to see what they were like. Some were cut with the stretch the wrong way. If the valve stretches along the length rather than across it probably won't work.



#9 wayman

wayman

    Chatty concertinist

  • Members
  • PipPipPipPip
  • 232 posts
  • Gender:Not Telling
  • Location:Sheffield, UK

Posted 31 May 2017 - 03:04 AM

With leather valves on hybrid reeds, to give valves extra snap we (Button Box) would do it just how it's done on melodeons: a little strip of spring-steel, held on at one end with a leather "dot" with a dot of PVA. Sometimes it helped further to give the spring-steel a little bit of arc (such that it contacted the valve about 4/5 of the way to its tip?) and a sharp bend away from the valve at its tip (so the end of the valve never caught the leather of the valve). The spring-steel strips came straight from an accordion parts supplier (FRM) and were available in different widths/strengths; we'd trim the length as needed. The dots we just punched out of scraps of really thin leather.

 

So I assume the same could be done on valves with traditional reeds, for those very low notes (which seems to be what Chris describes). At the least, it's something to experiment with. That's all valves seem to be, something to experiment with, marvel at their mysterious ways, and try not to get too frustrated  :huh: But I don't recall seeing this done with valves with traditional reeds; we'd use slightly thicker leather for those valves and generally that worked, or if it didn't we'd just glare at the valve a while and sometimes that would make it work :wacko: , and sometimes we'd rip it off and replace it and that would make it work  -_-


Edited by wayman, 31 May 2017 - 04:04 AM.


#10 Chris Ghent

Chris Ghent

    Heavyweight Boxer

  • Members
  • PipPipPipPipPip
  • 1058 posts
  • Gender:Male
  • Location:Blue Mountains NSW

Posted 31 May 2017 - 03:32 AM

In the time since that earlier post (five years ago!) I have experimented with those accordion springs. Even came across the need for the arc but not the bend at the tip. Yes, they work on a trad valve.

 

In general how my valving has changed over that time is I am valving harder than I did then. Light valves make a wonderful responsive concertina but they have no capacity to handle humidity swings. Today's perfect valve is tomorrow's fuzzy bumble.



#11 alex_holden

alex_holden

    Heavyweight Boxer

  • Members
  • PipPipPipPipPip
  • 580 posts
  • Gender:Male
  • Location:Lancashire

Posted 31 May 2017 - 07:10 AM

It sounds like my best bet may be to obtain a hide of the right sort of leather, so I can experiment with cutting valves of varying thicknesses and parts of the hide. I've read that it is a hair sheep, and the supplier I got these ready-made valves from described it as "half strained". Is there anything else I should be asking for when I try talking to leather suppliers, or better still can anyone recommend a UK leather supplier that will know exactly what sort of leather I need if I tell them it's for concertina valves?

#12 Dana Johnson

Dana Johnson

    Heavyweight Boxer

  • Members
  • PipPipPipPipPip
  • 663 posts

Posted 31 May 2017 - 03:16 PM

It sounds like my best bet may be to obtain a hide of the right sort of leather, so I can experiment with cutting valves of varying thicknesses and parts of the hide. I've read that it is a hair sheep, and the supplier I got these ready-made valves from described it as "half strained". Is there anything else I should be asking for when I try talking to leather suppliers, or better still can anyone recommend a UK leather supplier that will know exactly what sort of leather I need if I tell them it's for concertina valves?

The only thing of use I can add is to cut your valves in the grain direction. ( for most of the hide, except near the belly, this will be parallel to the animal's spine. This is the direction of least stretch. For any random piece of valve leather, try to stretch it in differen't directions, and when you find the least stretchy one, mark it. Valves cut along this direction will have the most spring back, while valves cut across it will be floppy in comparison.
Leather is tumble dried to soften it. Rewetting it thoroughly and drying it on glass will reset it close to its original state. I have seen valves of mine done this way that have maintained their properties over at least 10 years. I use Columbia organ leather's CPL ( chrome pneumatic leather, extra thick at a minimum for most valves and treat it this way. Otherwise it is too supple. Chris is quite right about it being a black art. I must remember to ask Voldemort what he does.
Dana

#13 Jake Middleton-Metcalfe

Jake Middleton-Metcalfe

    Chatty concertinist

  • Members
  • PipPipPipPip
  • 260 posts
  • Gender:Male
  • Location:Wolverton, Milton Keynes

Posted 31 May 2017 - 04:17 PM

Concertina valves can certainly be tricky.

 

With accordion reeds I found in the end that I had better luck with synthetic valves (very very thin plastic) Which gave slightly more volume and slightly better response than the accordion leather valves. Also easier to use. 

 

Perhaps if I cut some of those plastic valves into a suitable shape for a traditional concertina and tried it out in one it might perform well... or it might just be terrible. Did anyone ever try this?

 

Jake


Edited by Jake Middleton-Metcalfe, 31 May 2017 - 04:19 PM.


#14 alex_holden

alex_holden

    Heavyweight Boxer

  • Members
  • PipPipPipPipPip
  • 580 posts
  • Gender:Male
  • Location:Lancashire

Posted 01 June 2017 - 12:48 AM

The only thing of use I can add is to cut your valves in the grain direction. ( for most of the hide, except near the belly, this will be parallel to the animal's spine. This is the direction of least stretch. For any random piece of valve leather, try to stretch it in differen't directions, and when you find the least stretchy one, mark it. Valves cut along this direction will have the most spring back, while valves cut across it will be floppy in comparison.
Leather is tumble dried to soften it. Rewetting it thoroughly and drying it on glass will reset it close to its original state. I have seen valves of mine done this way that have maintained their properties over at least 10 years. I use Columbia organ leather's CPL ( chrome pneumatic leather, extra thick at a minimum for most valves and treat it this way. Otherwise it is too supple. Chris is quite right about it being a black art. I must remember to ask Voldemort what he does.
Dana


Thanks, that's a useful lead. The ready-made valves I bought do seem to be rather limp and floppy. When you dry the leather on glass, do you press it with something absorbent to keep it flat as it dries?

#15 Dana Johnson

Dana Johnson

    Heavyweight Boxer

  • Members
  • PipPipPipPipPip
  • 663 posts

Posted 01 June 2017 - 06:01 PM

The only thing of use I can add is to cut your valves in the grain direction. ( for most of the hide, except near the belly, this will be parallel to the animal's spine. This is the direction of least stretch. For any random piece of valve leather, try to stretch it in differen't directions, and when you find the least stretchy one, mark it. Valves cut along this direction will have the most spring back, while valves cut across it will be floppy in comparison.Leather is tumble dried to soften it. Rewetting it thoroughly and drying it on glass will reset it close to its original state. I have seen valves of mine done this way that have maintained their properties over at least 10 years. I use Columbia organ leather's CPL ( chrome pneumatic leather, extra thick at a minimum for most valves and treat it this way. Otherwise it is too supple. Chris is quite right about it being a black art. I must remember to ask Voldemort what he does.Dana

Thanks, that's a useful lead. The ready-made valves I bought do seem to be rather limp and floppy. When you dry the leather on glass, do you press it with something absorbent to keep it flat as it dries?

I smooth the leather on the glass to press out extra water, but not to try to compress it. Then lay a paper towel on it and use a block printing roller gently on it. The paper knower keeps the roller from stretching the leather. Only once have I had the leather cup a bit when it dries on the glas, but removing it just before fully dry should help that. It was a large piece ( about a foot square ) and the leather dried more near the edges first. I have also speeded things up with a hair dryer set on cool which keeps things nice and even.

#16 Dana Johnson

Dana Johnson

    Heavyweight Boxer

  • Members
  • PipPipPipPipPip
  • 663 posts

Posted 01 June 2017 - 06:21 PM

Concertina valves can certainly be tricky.
 
With accordion reeds I found in the end that I had better luck with synthetic valves (very very thin plastic) Which gave slightly more volume and slightly better response than the accordion leather valves. Also easier to use. 
 
Perhaps if I cut some of those plastic valves into a suitable shape for a traditional concertina and tried it out in one it might perform well... or it might just be terrible. Did anyone ever try this?
 
Jake

I have tested out Mylar valves, which had potential. They stay flat and spring back well. And curl up and down reducing valve slap. Unfortunately, the material does not come in fine enough gradations. The .001inch material worked for high valves, but .002 was twice as thick .003 x3, .004x4, much too great a distance between. The stiffness increases faster than the thickness, so I simply could not find something in the middle that wasn't too stiff, while the .001 was too thin for notes below G5. The stiffness muted the lower notes too much. I have toyed with reducing the hinge width to be able to use thicker stock and control the stiffness by reducing the width at the point wher the glue stops. Also needs abrading to get glue to stick well. I tried notching the valves at the base, but hard to accurately control the width. Also to punch a hole there, leaving a hinge on either side. Also hard to control. I may try putting a little slit on either side with a razor blade to reduce the bending width, but am leary of it being crack prone. Haven't really given up yet.

#17 d.elliott

d.elliott

    Heavyweight Boxer

  • Members
  • PipPipPipPipPip
  • 1205 posts
  • Gender:Male
  • Location:Sheffield, South Yorkshire, England

Posted 05 June 2017 - 11:56 AM

Just picked up om this thread, its about valves for big reeds?

 

I do a lot of work with Baritones, having re-valved no less than three in the last six weeks. 

 

I have also been offered half strained  leather for hand cut valves, indeed I took a delivery of half strained leather pre-cut standard valves. Half strained is just too stiff and inflexible for standard valves, and not much better for hand cuts. I rejected several £100's of valves back to the supplier who sent a load of samples of alternatives, none of which I was really happy with. (I suspect we are using the same supplier Alex,) The original leather I used to get was was Mordant sheep.

 

On big reed instruments I have seen synthetic valves, which were less than successful when playing pianissimo. Thin rubber insertion which had the same problem but just killed all resonance.  I have also seen valves glued together full length. Valves with another valve as a part length backer. all of which lacked play sensitivity.  

 

The trick is in valve springs, I use the same spring wire as a coil action springs from, and fit them in a similar way to the heavier OEM valve springs. but at a shallower angle to that the maximum opening is about 50% more than the valve pin height in the mating chamber. In the chambers valves are constrained by two or three pins, usually positioned to restrict the valve on opening so it can fall back or be easily drawn down by airflow to cover the reed pan vent. The valve spring is there for the same purpose, not the same way as an accordion valve vire works.

 

Hope this helps

 

Dave



#18 alex_holden

alex_holden

    Heavyweight Boxer

  • Members
  • PipPipPipPipPip
  • 580 posts
  • Gender:Male
  • Location:Lancashire

Posted 05 June 2017 - 02:10 PM

Thanks Dave. The valves I've had problems with aren't very low: the lowest is C below middle C. I'm working on getting hold of some appropriate leather so I can try cutting my own.

If I'm following you correctly, on very low reeds you put valve springs on the bottom of the reed pan to prevent the bottom valves opening too far, in the same way as the chamber pins restrict the opening of the top valves.




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users