of reeds, valves and ignorance

[KiwiSqueezer]

More questions about the restoration of my 'ladies model' Paramount accordion. I'd be very grateful for any help or advice.

The amount of work required on this accordion makes professional restoration completely uneconomical - and accordion technicians in New Zealand are almost unknown. I think the nearest to me would be a one-hour 'plane ride away. I hate to think of this pretty little accordion being scrapped because of economics. I'm capable of the restoration work, but I'm somewhat out of my depth because I know so little about accordions.

This accordion has two banks of reeds in each of the treble and the bass side. I wish to replace all the reed valves, the original, which are leather, having curled and stiffened, presumably because of years of storage in the damp.

Originally, I thought I would use plastic and synthetic leather valves, for longevity and to obviate the curling problem, but I'm getting frustrated by suppliers specifying their valves so poorly. It's difficult to understand what's being offered. Just what sizes are in an (expensive) kit of valves 'suitable for a blah, blah, blah'? It's not helpful, especially when you don't have a 'blah, blah, blah'! Also, the minimum packaged quantities make considerable waste inevitable, unless a lot are cut down. If I knew more about accordions, I expect it would be easier, but I don't, so it isn't...

From an availability point of view, it may be easier to use leather valves. Assuming good storage conditions, what would be their expected life?

Then there's the question of booster springs. Where can I find guidance about length and thickness (diameter) required in relation to valve dimensions? There must be some rules of thumb available...

The largest bass reeds are about 5.9mm wide, at their middle, and are fitted with 10mm wide leather valves, 55mm long. I can't find synthetic valves wider than 8.5mm wide. How important is the width of valves? One might think that anything wider than the aperture in the reed plate would be OK, but is it that simple? All the leathers in this accordion seem to be wider than available corresponding-length plastic or synthetic valves. Is that expected?

Should I just stick with leather, and accept that I would have to cut most to fit?

Is there a source of information about the use of multi-layer synthetic/plastic valves?

Here's a 'rationalised' list of the existing valve dimensions (assumed slightly 'odd' sizes have been ignored, on the assumption that they were manufacturing aberrations). All dimensions mm.

Treble side: 39, 37, 35 X 7.5; 34, 33 X 7; 30, 29, 27 X 6.5; 26, 25, 24, 23, 21 X 6.

Bass side: 55 X 10; 45 X 9; 37 X 7.5; 34 X 7; 33, 31, 29 X 6.5.

 

[Tor]

I'm thinking towards doing much the same with an accordion I have. AIUI, reed leathers are sold in some various widths and a few lengths, which must be cut to exact length. Part of the minimum orders seeming high is due to the cost of material being so low it's not very economical for suppliers to separate them out more, especially as accordion restoration isn't common as a hobby to do one-off due to the skill investment required.

Booster springs, if you really want to replace and get exact diameters, you're probably better off getting a dial or digital caliper and measuring, unless they've fallen off and you can't sort.

www.accordionrevival.com has a lot of useful information, though someone here may be better able to suggest suppliers to NZ. I've communicated with George a couple times and he's also been friendly and helpful.

 

[debra]

There are no plastic valves of sizes suitable for large bass reeds. Leather (real or faux) needs to be used for at least the lowest two reed banks of the bass side and the lowest 15 to 20 notes of the treble L reeds (and for the lowest M reeds). These valves all need metal booster springs to help them stay closed and offer enough resistance. The required strength of the springs you need to determine experimentally to some extent, to find out what is needed so the pitch does not go up too much on low volume. For higher notes you can use synthetic valves. I have 5 or 6 sizes of synthetic (plastic) valves. Having enough variety in widths is more important than in length, and of course also having the smallest ones too. Bags of plastic valves are not very expensive and once you start working on accordions (tuning) you end up replacing more valves than you can imagine, because it is sometimes hard to scratch the inside reed without damaging the outside valve.

 

[KiwiSqueezer]

Thanks for your thoughts, but I fear my specific questions remain largely unanswered. Perhaps I rambled on too much, and wasn't clear enough. Let's try again...

As you can see, from the list of valve sizes in my previous post, this little accordion has relatively small bass reeds. The lowest bank uses 55 X 10 and 45 X 9 leather valves only - equal numbers of each. 55.3 X 8.5 is available in leather/plastic foil composite, and 45 X 6.5 is available in plastic. The other bass bank uses leathers ranging from 29 X 6.5 to 37 X 7.5, and treble side leathers range from 21 X 6 to 39 X 7.5, all of which seems to be covered by the available range of plastic valves.

Questions:

1. All the existing leathers are wider than similar-length plastic valves. Any comments on why, and whether this is going to be a problem? Are narrower-than-original valves likely to be OK?

2. It looks like I will have to use leather/foil valves for half of the lowest bank's reeds (one voice, if I've got the terminology right). Should I use leather/foil for other half (voice) also, or would plastic be OK?

3. Accordion terminology is still unfamiliar to me. I note your comments about treble L and M reeds, but don't know how to use that info. The treble switches are labelled 'bassoon' and 'violin'. At present, I can't tell you the reeds' frequency range. However, in my ignorance, it seems reasonable to fit any preferred construction of valve, provided that the required size is available. Is this correct?

4. Plastic valves may have multiple layers. If the valve requires shortening, are all layers to be trimmed in proportion?

5. Adhesive. The range available here in NZ is restricted, and brand names are different. What type of adhesive is recommended? In other words, rubber-based, organic-solvent-containing, 'super-glue', what? Bostik is a manufacturer's brand name - it doesn't identify a particular adhesive - there are many different Bostik adhesives.

 

[Tor]

3. The L reed bank is commonly called Bassoon. Your "Violin" switch in this case is your M reed bank. A very common 2/4 reed bank configuration, just like the one I thinking similarly for. It'll be obvious which is which, as the bassoon reeds are much bigger than the clarinet reeds. That's the more common designation, violin is more commonly used for two M/clarinet reeds in unison, but there's no standardization.

 

[boxplayer4000]

KiwiSqueezer.
I sympathise with your confusion about valves. The lengths, widths and material is endless. As a general rule valves are made to suit reed lengths. (With ‘length’ in mind it is worth noting that plastic valves come in two styles ie. one with a hole to fit over the reed rivet and the other without. There’s about a 5mm difference in length between them. I associate the ones with holes as being ‘Hohner’ type, maybe a wrong assumption).

I prefer plastic valves because they generally come in 2 or 3 layer construction and by cutting these layers the strength of the valve can be adjusted so that the ‘lift’ of the valve is correct. ie. too little lift would stifle the reed (lower its pitch) and too much is inefficient and it could engage with a neighbouring reed block. I also find from experience that good plastic valves will last as long as a leather ones, if not longer, but I’m sure this is down to the conditions the instrument is kept in.

I note there is a New Zealand Accordion Association and one or two shops on-line and I suggest (if you haven’t already done it) you approach them for advice. If you specify your accordion make/type/size/voices, bass and treble a knowledgeable supplier should be able to supply valves to suit.

 

[boxplayer4000]

KiwiSqueezer,
Just noticed your query re. adhesive. The answer is the best possible (no cheap substitutes) because the possibility of having to re-do
valving just has to be avoided. You mention Bostik is available in NZ and I don't think you would go far wrong with one of their range which suits, metal, plastic, leather etc. Uhu and Pattex are also mentioned on this site.

 

[colinm]

Thanks for your thoughts, but I fear my specific questions remain largely unanswered. Perhaps I rambled on too much, and wasn't clear enough. Let's try again...

As you can see, from the list of valve sizes in my previous post, this little accordion has relatively small bass reeds. The lowest bank uses 55 X 10 and 45 X 9 leather valves only - equal numbers of each. 55.3 X 8.5 is available in leather/plastic foil composite, and 45 X 6.5 is available in plastic. The other bass bank uses leathers ranging from 29 X 6.5 to 37 X 7.5, and treble side leathers range from 21 X 6 to 39 X 7.5, all of which seems to be covered by the available range of plastic valves.

Questions:

1. All the existing leathers are wider than similar-length plastic valves. Any comments on why, and whether this is going to be a problem? Are narrower-than-original valves likely to be OK?

2. It looks like I will have to use leather/foil valves for half of the lowest bank's reeds (one voice, if I've got the terminology right). Should I use leather/foil for other half (voice) also, or would plastic be OK?

3. Accordion terminology is still unfamiliar to me. I note your comments about treble L and M reeds, but don't know how to use that info. The treble switches are labelled 'bassoon' and 'violin'. At present, I can't tell you the reeds' frequency range. However, in my ignorance, it seems reasonable to fit any preferred construction of valve, provided that the required size is available. Is this correct?

4. Plastic valves may have multiple layers. If the valve requires shortening, are all layers to be trimmed in proportion?

5. Adhesive. The range available here in NZ is restricted, and brand names are different. What type of adhesive is recommended? In other words, rubber-based, organic-solvent-containing, 'super-glue', what? Bostik is a manufacturer's brand name - it doesn't identify a particular adhesive - there are many different Bostik adhesives.

I am an amateur repairer. So far as I can gather , revalving is an art because the valve material , its stiffness and size , the glue type and length of gluing all have an effect on the tuning, you change any of them at your peril, at the same time you run the risk of getting foreign material in the reed, and causing damage to valves as you take the blocks in and out, hope that explains some of the problems.

 

[KiwiSqueezer]

The selection of a suitable adhesive is, at least to my mind, not easy. I think the adhesive should grab quickly, cure quickly and be easy to remove, for future re-valving. It should actually adhere to the materials, without causing damage. Plastic valves seem to be either 'vinyl', which I assume to be PVC or 'Mylar', which is, IIRC, PET film. Some plastics are very difficult to glue, some are easy, but these generally(/) are glued with solvent adhesives. There are reports of some adhesives causing wrinkling of some plastic valves. PVC pipes are commonly solvent-welded, so one has to be careful about organic solvent content of adhesives. Unfortunately, the packaging (at least here in NZ) has been dumbed down so much, you really get no idea of what's in the tube. And one should probably be careful about water-based adhesives, lest they cause corrosion. Time for trial and error, I suppose.

Colinm, thanks for your gloomy pronouncement. It matches my mood, as I get ever more frustrated by the incomlete or misleading information that seems to accompany accordion technology. It does indeed seem more art than science. Unfortunately(?) I'm a scientist...

 

[Tor]

There's no need to worry about the adhesive not damaging the valve or being able to be removed from it, except insofar as it isn't so incompatible as to make the valve unfit for purpose before it wears out normally. Standard practice is to just replace with new any time it gets damaged for any reason.

Fit for purpose on the metal means it can scrape off. Ideally it'll stick sufficiently to the valve that when you pull it off in the future the adhesive comes off with it, but it stays on the metal that vibrates with the reed until deliberately removed. I tend to be a traditionalist in materials, so would first try shellac on leather in most all cases, despite my high humidity environment.

AIUI, the shoe adhesives are thought to be better because they are designed to hold without breaking in a high shear stress location that bends and flexes. OTOH, I could see the argument that in theory the more flexible adhesive could very slightly deaden the sound. In practice I've never heard of anyone finding audible difference.

 

[Dingo40]

Paul uses the shoe glue!

 

[debra]

Thanks for your thoughts, but I fear my specific questions remain largely unanswered. Perhaps I rambled on too much, and wasn't clear enough. Let's try again...

As you can see, from the list of valve sizes in my previous post, this little accordion has relatively small bass reeds. The lowest bank uses 55 X 10 and 45 X 9 leather valves only - equal numbers of each. 55.3 X 8.5 is available in leather/plastic foil composite, and 45 X 6.5 is available in plastic. The other bass bank uses leathers ranging from 29 X 6.5 to 37 X 7.5, and treble side leathers range from 21 X 6 to 39 X 7.5, all of which seems to be covered by the available range of plastic valves.

Questions:

1. All the existing leathers are wider than similar-length plastic valves. Any comments on why, and whether this is going to be a problem? Are narrower-than-original valves likely to be OK?

Take valves of the width you need and cut the length to size. For the multi-layered valves, cut down other layers when needed. "Needed" means when it's needed to make the frequency more independent from the sound volume. If the reed plays too low at low volume (but fine at higher volume) then cut the second layers down a bit. You will notice that this helps the frequency to go up at low volume.

2. It looks like I will have to use leather/foil valves for half of the lowest bank's reeds (one voice, if I've got the terminology right). Should I use leather/foil for other half (voice) also, or would plastic be OK?

I tend to use leather for the lowest two reed banks on the bass side. (And the lowest notes on the treble side.)

3. Accordion terminology is still unfamiliar to me. I note your comments about treble L and M reeds, but don't know how to use that info. The treble switches are labelled 'bassoon' and 'violin'. At present, I can't tell you the reeds' frequency range. However, in my ignorance, it seems reasonable to fit any preferred construction of valve, provided that the required size is available. Is this correct?

Bassoon is supposed to be L, but manufacturers choose names rather freely. I meant L as the lowest sounding reed bank and M as the middle (and there may be an H bank if you have a register called "piccolo").

4. Plastic valves may have multiple layers. If the valve requires shortening, are all layers to be trimmed in proportion?

No, see question 1: you trip the other layers on as much as needed to get the right frequency at low volume.

5. Adhesive. The range available here in NZ is restricted, and brand names are different. What type of adhesive is recommended? In other words, rubber-based, organic-solvent-containing, 'super-glue', what? Bostik is a manufacturer's brand name - it doesn't identify a particular adhesive - there are many different Bostik adhesives.

I recommend to use a "shoe glue". Best is to not just go to a hardware store to find the right glue, but go to a shoe maker. The best glue is the glue (s)he uses but sometimes shoe makers may be unwilling to sell you that glue. I have had good experience with shoe makers by telling them I needed the glue not for shoe repair but for accordion repair. That means you are not going to steal their business. But they will also have tubes of shoe glue they sell to "normal" customers and that will do too.

 

[KiwiSqueezer]

Well, I'm still confused... I'm sure the problem is my ignorance (perhaps compounded by stupidity). In my ignorance, I assumed that any valve (plastic or leather) that physically covered the reed and wouldn't hang up in the reed chamber, would be OK. In other words, select by size alone. All the reeds in this little accordion, with the exception of the lowest octave bass reeds (C2 lowest note), are small enough for plastic valves to fit. However, Paul recommends leather from around C4 downwards. Why? Is this because of reed-valve interaction at low frequencies? Should plastic valves not be used below a certain frequency, regardless of reed dimensions?

Terminology problems again. When applied to reeds, does 'rank' mean one lot of reeds that make up a 'voice', or one set of reeds on a (two-sided) reed block, that are selected by the slide? The bass side of this accordion has 2 double-sided reed blocks, each with 2 sets of 12 reeds. The C3 and C4 octave (each on different blocks) always sound; the toggle-action switch allows the C2 and another set of C4 octave reeds to sound as well. Does this make sense? Have I misunderstood? So, how many 'ranks' of reeds are there in this accordion's bass side? (Please be patient and gentle, one has to start somewhere, and, in my case, it's from complete ignorance...).

 

[boxplayer4000]

If you look for complications you will certainly find them. Learn by your mistakes.
Start by selecting reeds by size. Leather, veiled, plastic etc.
The valve only needs to fulfil two functions: They must be close fitting and perfectly flat against the reed plate and open a sufficient amount when played ie. too little will stifle the reed and lower the pitch (your tuner will tell you) and too much might make the valve engage with adjacent reed block etc.

 

[debra]

If you look for complications you will certainly find them. Learn by your mistakes.
Start by selecting reeds by size. Leather, veiled, plastic etc.
The valve only needs to fulfil two functions: They must be close fitting and perfectly flat against the reed plate and open a sufficient amount when played ie. too little will stifle the reed and lower the pitch (your tuner will tell you) and too much might make the valve engage with adjacent reed block etc.

Actually more functions: the valves must (possibly with the aid of booster springs) offer enough resistance so that they don't open too far as they will touch something (on the outside especially) like the next reed block or the bellows. Bass valves on the outer blocks have been known to get caught in bellow folds and sometimes even ripped off. Then, the resistance must evolve in such a way that there is enough resistance at low volume so the pitch does not go up. With multi-layer plastic valves it's a matter of finding how much longer the bottom layer needs to be than the second layer so that the frequency is reasonably stable. With leather valves it's a matter of finding the right size (strength) of booster spring and adjusting the "kink" near the base to adjust the force. Adjusting valves is a lot more complex than just selecting one and glueing it on. A tuning table can help a lot in fine-tuning the valve strength (to get a stable frequency, not to get the right frequency).
Even when you get a new accordion you may find that especially lower notes on push will go down in frequency but some notes much more than other notes. That's because the factories do not spend the time and effort to get the spring selection and adjustment just right for minimal "sag". One might hope that at least on very expensive accordions the factory would put in the required effort, but I'm not sure they actually do.