Materials Traditional Or Modern?

[Theo]

I know the topic of choice of materials for restoration work is one which has been debated before, but I can't find any reference in the archive to use of modern materials for concertina valves.

 

This is the kind of debate which runs and runs among restorers of old artefacts of all kinds, and I have long experience of the arguments among restorers of old motorcyles. The debate usually hinges around where one decides the benefit lies between a historically accurate restoration on the one hand, and of re-making the artefact as a practically useful object. In the context of old bikes, do you want a dislpay or a rider? And there is the third way, which is to perform no restoration at all, and simply conserve the object as found, as a historical document. Any of these three approaches can be valid. I'm not in any way wanting to decry their validity in what follows, which relates only to restoration to produce a useful functioning artefact, whether it be bike or in this case musical instrument.

 

Valves in freereed instruments have traditionally been made of leather. In the 19th and early 20th centuries this was without doubt the best choice, and may still be. Leather does have some disadvantages though. As a natural product it is subject to variation in quality, and to gradual deterioration. Over time leather can loose its shape, loose its springiness, or become too stiff. In the accordion world valves made of plastic film have been used for many decades, and many of the best quality instruments are now built with plastic valves. Experience has shown that they remain stable for many decades, and only need to be replaced as a result of gross damage, such as careless handling. My own experience suggests that there is some difference in the acoustic properties. The same instrument with leather or plastic valves sounds subtly different. With plastic valves slightly brighter, with leather slightly more mellow. With valves of any type which do not lie completely flat there can be a slower reed response at low air pressure, and this is more likely with leather.

 

My questions are related to valve materials in concertinas. In my fairly limited experience I have only ever seen leather valves, and I have always been conservative and used the same material to replace old ones. I have also seen valves that are only 2 or 3 years old which are not lying flat and wonder why this happens, and why we remain faithful to this material when others are available that may be superior.

 

I'm just starting on a rebuild of a basic 20 key anglo which needs new valves, so I plan to try plastic valves in that. I'll be using valves designed for accordions, and I expect to modify them in length and/or width, and possibly change the number of layers used. But that is normal practice with accordions, and even leather concertina valves sometimes need to be trimmed too.

 

Have plastic, or other materials been tried for concertina valves? If so how did they perform? I'd like to hear what experience there is of this material.

 

Theo Gibb

[OLDNICKILBY]

I know the topic of choice of materials for restoration work is one which has been debated before, but I can't find any reference in the archive to use of modern materials for concertina valves. 

 

This is the kind of debate which runs and runs among restorers of old artefacts of all kinds, and I have long experience of the arguments among restorers of old motorcyles.  The debate usually hinges around where one decides the benefit lies between a historically accurate restoration on the one hand, and of re-making the artefact as a practically useful object.  In the context of old bikes, do you want a dislpay or a rider?  And there is the third way, which is to perform no restoration at all, and simply conserve the object as found, as a historical document.  Any of these three approaches can be valid.  I'm not in any way wanting to decry their validity in what follows, which relates only to restoration to produce a useful functioning artefact, whether it be bike or in this case musical instrument.

 

Valves in freereed instruments have traditionally been made of leather. In the 19th and early 20th centuries this was without doubt the best choice, and may still be.  Leather does have some disadvantages though.  As a natural product it is subject to variation in quality, and to gradual deterioration.  Over time leather can loose its shape, loose its springiness, or become too stiff.  In the accordion world valves made of plastic film have been used for many decades, and many of the best quality instruments are now built with plastic valves.  Experience has shown that they remain stable for many decades, and only need to be replaced as a result of gross damage, such as careless handling.  My own experience suggests that there is some difference in the acoustic properties.  The same instrument with leather or plastic valves sounds subtly different.  With plastic valves slightly brighter,  with leather slightly more mellow.  With valves of any type which do not lie completely flat there can be a slower reed response at low air pressure, and this is more likely with leather.

 

My questions are related to valve materials in concertinas.  In my fairly limited experience I have only ever seen leather valves, and I have always been conservative and used the same material to replace old ones.  I have also seen valves that are only 2 or 3 years old which are not lying flat and wonder why this happens, and why we remain faithful to this material when others are available that may be superior.

 

I'm just starting on a rebuild of a basic 20 key anglo which needs new valves, so I plan to try plastic valves in that.  I'll be using valves designed for accordions, and I expect to modify them in length and/or width, and possibly change the number of layers used.  But that is normal practice with accordions, and even leather concertina valves sometimes need to be trimmed too.

 

Have plastic, or other  materials been tried for concertina valves?  If so how did they perform?  I'd like to hear what experience there is of this material.

 

Theo Gibb

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[OLDNICKILBY]

Not only is there a problem as to the material, poly-ethylene,poly urethane thermo plastic rubber ,silicone or santoprene all of which have the memory to sort of do the job. The real problem is "How the hell do you glue it ?

Perhaps it would be better to stick to leather

However it may upset some purists that I sometimes use on tinas that are of little value silicone tube for the button bushes instead of the traditional felt which I find to be too time consuming for a low value instrument.At least it gets someone else playing a loan -or should I say lone-tina

[Richard Morse]

My questions are related to valve materials in concertinas.  In my fairly limited experience I have only ever seen leather valves, and I have always been conservative and used the same material to replace old ones.  I have also seen valves that are only 2 or 3 years old which are not lying flat and wonder why this happens, and why we remain faithful to this material when others are available that may be superior.

We (the Button Box) remain faithful to the best material for the job, and for quality concertinas that is hair sheep vavles. Those that lasted 2 or 3 years were most likely were NOT hair sheep - nor chosen, treated, skived, cut, and grain-oriented correctly. We haven't found a superior material, and it appears that Dipper and Dickinson haven't (though they probably have more historical inertia than we have).

 

It's the properties of hair sheep hide - it's cellular nature - that makes it so good. The choice of which part of the hide, tanning treatment, skive, shape of cut and grain orientation are choices that will make any leather a better performer but hair sheep seems to be the superior TYPE of leather - that is available to historical English makers. There may be other types of leather that will work as well (wombat?)....

 

For his first few years of production, Haymish Bayne used silicone sheet, which seems to work quite well! It's cheap, resonably quiet, resilient.... Not wonderful to glue, but can be with the right adhesive.

 

We also use a lot of plastic and foam valves - but always associated with accordion reeds. They DO work well.... at leat for a while. The biggest problem with plastic vavles seems to be that they take on a static electrical charge that attracts microscopic dust and smoke to them which in time builds up thick enough (which is still a very thin film) to allow moisture to cling to them.... The resultant residue get to be sufficient to make the vavle stick - or not become free - of the reedplate easily enough. In the worst cases, such as having that build-up and not having played the instrument for a month, the valves cannont be unstuck by air pressure and must be replaced.

 

Have plastic, or other  materials been tried for concertina valves?  If so how did they perform?  I'd like to hear what experience there is of this material.

 

We've never tried plastic vavles on any traditionally-constructed concertinas due to our experiences with them in accordions. Okay for Stagis though as they're not expected to last very long anyway. We use leather valves for our Morse concertinas (even though they have accordion reeds in them).

[Peter Brook]

hair sheep seems to be the superior TYPE of leather

 

Anyone tried Kangaroo? It is being used more and more as the leather of choice in motorcycle gloves and race suit leathers. I know the job of a concertina valve and protective clothing for motorcyclists are vastly different, but I understand it is chosen because:

 

It is soft and retains this softness

It is very strong and doesn't tear very easily

There is no barbed wire in Austrailia to create scars in the leather

[Chris Ghent]

hair sheep seems to be the superior TYPE of leather

 

Anyone tried Kangaroo? /

 

I understand it is chosen because:

 

It is soft and retains this softness

It is very strong and doesn't tear very easily

There is no barbed wire in Austrailia to create scars in the leather

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While some of the Australian makers use kangaroo for bellows leather, I can't imagine any of the kangaroo I have seen being better than sheep for valves. It is definitely capable of being both tough and soft, but it is not soft in the way sheep is.

 

It comes in three grades, described to me by a bloke at the tannery like this; one is relatively perfect finish, two has only one small wire strike, and three means a kangaroo with very poor judgement of fence height. We have lots of barbed wire here. Little concertina wire luckily.

 

Best Wishes

 

Chris

Edited February 25, 2005 by Chris Ghent

[Stephen Chambers]

Anyone tried Kangaroo?

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We had Darius Bartlett do a concertina repair workshop at the Mrs. Crotty Festival here a few years ago, at which he thoroughly recommended the use of kangaroo skin for bellows.

 

The only trouble is, we're a bit short of kangaroos around here ...

 

Mind you, that doesn't stop some pretentious people driving four wheel drives (SUVs) with "'roo bars" fitted, just for "effect", but they'd get an awful shock if a kangaroo actually jumped out in front of them !

[d.elliott]

When I first bought my English system baritone it had rubber valves fitted, looked like black tyre inner-tube rubber. The effect was a very fast closure of valves, but they damped the reed-pan, giving a very clean but muted tone. I replaced the valves with leather, fitted replacement valve wires (these had been previously removed and discarded). The instrument still kept some of its speed, but the tone and projection immediately improved.

 

The worst part was getting rid of the rubber glue used to affix the rubber valves.

 

Dave

[Greg Jowaisas]

And if you had replaced the rubber valves with more of the same you would have been....a retyree, Dave!

 

Regards (I think),

 

Greg

[Chris Ghent]

We had Darius Bartlett do a concertina repair workshop at the Mrs. Crotty Festival here a few years ago, at which he thoroughly recommended the use of kangaroo skin for bellows.

 

The only trouble is, we're a bit short of kangaroos around here ... 

 

Mind you, that doesn't stop some pretentious people driving four wheel drives (SUVs) with "'roo bars" fitted, just for "effect", but they'd get an awful shock if a kangaroo actually jumped out in front of them ! 

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They give you an awful shock here too, roo bars or not.

 

If anyone is jumping up and down wanting kangaroo leather, this mob, http://www.packerleather.com/index.html near Brisbane can supply it. It costs around $30 AUD a skin. Hard to do a good job of buying leather without getting your hands on it though.

 

Chris

[Clive Thorne]

I replaced a few valves on my Jeffries with plastic and they seemed to work fine (the leather ones had badly curled). What I used was plastic shimming sheets, which allowed me to play around with different thicknesses. Mind you when I sent the box off to Colin Dipper to do some more serious work he replaced them with leather again!

 

My general attitude is to use the best meterial for the job irrespective of if its traditional or not. Obviously traditional materials have the advantage that their performance is known, but if no-one tries newer materials then we'll never make any progress.

 

Regarding glues, as far as I know, polypropylene is the only one that no glues will stick.

 

Clive.

[Theo]

Thanks to everyone for their thoughtful contributions.

 

Richard the information about the precise type of leather you use was very helpful, as was the experience of plastic valves becoming coated and sticky. I've not come across this problem with. I've not heard of this problem with "big boxes" either from players, or repairers. I wonder if its something about the different instruments that makes one more prone to this particular problem.

 

As an experiment I will be using plastic valves on a basic anglo that I'm working on just now.

 

Theo

[Richard Morse]

We've repaired (replaced all the valves, rewaxed, retuned) many boxes with plastic valves - enough to make some "why" theories. This happens ONLY with accordion type reeds, and happens primarily with button boxes (or to be more accurate - we get a lot more BA's in for repair with this sticky-plastic-valve problem than PA's). Age of the box doesn't seem to be an issue, but it does have had to be played a *lot* to get enough residue to be problematic.

 

The first things we notice when opening up those boxes is that they all smell (okay - reek) of tobacco smoke and there are dark marks all around the reeds and air passages to the most commonly used notes. The really bad ones look like someone's been in there with a small spray can of black paint. The interesting thing is that some boxes have this SPV problem with very little smoke darkening while some don't appear to have significant SPV until the entire inside of the box is coated.

 

Such are the conditions and effects. I'm wondering if this means that those boxes were played a lot in bars and pubs where the humidity level is fairly high and smoky atmosphere dense. Maybe the operating valves become slightly charged from operation to attract the particulates which can absorb the moisture in the air that catches more particulates that become a thin glue-like slurry? Maybe there's no static electrical in the equation but everything stems from moisture being the primary culprit which will absorb the smoke? Thoughts anyone?

 

I note that leather valves don't seem to have this problem. Maybe because they absorb and diffuse moisture readily? Also for traditional concertinas, the valve seats against wood (an non-uniform material which is also moisture permeable) rather than a very smooth (machined metal and impervious) surface?

[JimLucas]

Such are the conditions and effects. I'm wondering if this means that those boxes were played a lot in bars and pubs where the humidity level is fairly high and smoky atmosphere dense. Maybe the operating valves become slightly charged from operation to attract the particulates which can absorb the moisture in the air that catches more particulates that become a thin glue-like slurry? Maybe there's no static electrical in the equation but everything stems from moisture being the primary culprit which will absorb the smoke? Thoughts anyone?

My thought is that moisture isn't the problem, it's the components of the tobacco smoke itself. Those oils, tars, and more complex hydrocarbons will cling to plastics -- which are also (very) complex hydrocarbons -- in a way that water won't. (Coat a plastic bottle with oil, and then try to get it all off without using detergent.) Some are naturally gummy and sticky -- characteristics of "tars", after all -- and any unsaturated bonds can lead to cross-linking, the same process by which plastics themselves are made, which can make them even gummier. (Ever leave a bottle of polyunsaturated cooking oil on the shelf for several months after use, then discover a gummy residue around the top? That's "natural" plastic.)

 

I note that leather valves don't seem to have this problem. Maybe because they absorb and diffuse moisture readily? Also for traditional concertinas, the valve seats against wood (an non-uniform material which is also moisture permeable) rather than a very smooth (machined metal and impervious) surface?

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Wood and leather also absorb and diffuse oils and other hydrocarbons. No water needed. That's why bear grease and mink oil are used for waterproofing boots, and various oils for polishing wooden furniture.

[Stephen Chambers]

I don't know about the science of it, but I would only ever have leather valves in my own instruments, simply because they make them sound better.

[Theo]

Stephen

 

I would only ever have leather valves in my own instruments, simply because they make them sound better.

 

Interesting you should say that Stephen. I have heard many people say that, but I wonder how you have arrived at that point of view? Its not often one gets to try the same box with different valves in order to make a fair comparison. I got started on this train of thought when I changed a diatonic box I play from leather to plastic. To my ear the sound was (very slightly) improved with the plastic valves. A bit more volume, and more "character". Very hard I know to find words to convey the nuances, but I would guess that the higher harmonics were enhanced.

 

Richard

The first things we notice when opening up those boxes is that they all smell (okay - reek) of tobacco smoke and there are dark marks all around the reeds and air passages to the most commonly used notes. The really bad ones look like someone's been in there with a small spray can of black paint. The interesting thing is that some boxes have this SPV problem with very little smoke darkening while some don't appear to have significant SPV until the entire inside of the box is coated.

 

Thank you for sharing your experience. It's clearly a serious problem. Perhaps the evidence could be used to support legislators who wish to ban smoking in bars. Clearly the health of our musical instruments is at stake, as well as our lungs!

 

Theo

[JimLucas]

The interesting thing is that some boxes have this SPV problem with very little smoke darkening while some don't appear to have significant SPV until the entire inside of the box is coated.

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Could it depend on the kind of plastic used for the valves?

For that matter, how many different kinds of plastic have been used for valves?

I would expect that all sorts of properties and effects would differ among different plastics, just as among differnt kinds of leather.

[Clive Thorne]

(or to be more accurate - we get a lot more BA's in for repair with this sticky-plastic-valve problem than PA's).

 

 

Perhaps this indicates that Button box players tend to hang around seedy smokey bars whereas piano box players are more of the "joys of spring" open air type?

 

Clive