Reed Metals

[Dave Weinstein]

Is there any material which has been used for reeds which offers the sweetness of the brass reeds without the drawbacks (falling out of tune and breaking)?

 

--Dave

[Ivan Viehoff]

I wonder what kind of brass "brass reeds" are actually made of? There are many kinds of brass, but springiness is not generally a property one associates with brass. If one wants a springy copper based alloy, then the traditional material is phosphor bronze. Perhaps this is what brass reeds are really made of. Or if they aren't, perhaps they ought to have been.

 

Copper alloys generally have a much worse tendency to creep (which translates to go out of tune) and suffer fatigue failure (ie break in response to a large number of flexes) than equivalent types of steel.

 

I notice that Mr Morse has been having discussions with aerospace materials companies in sourcing a metal for his future concertina reeds. I wonder what they will be giving him. Perhaps one can find a modern copper alloy with better properties. Beryllium copper is a superior modern spring material, for example.

 

I suspect that historically the steels used for steel reeds would be so-called "spring steel", ie a rolled high carbon steel of suitable temper, related to the kind of steels still used for hack-saw blades, etc. I would guess the relative harshness of old steel reeds comes from the fact that the material is springier than that used for "brass reeds". So perhaps the alternative is to use a less springy steel.

 

High quality modern accordian reeds may well be some kind of stainless steel carefully selected for its spring properties. Stainless steels are a surprisingly recent invention, and would not have been available to Messrs Lachenal and Wheatstone. (They didn't have plastic either, I would point out to the person who suggested that Lachenal "bone buttons" might be plastic.) Today stainless spring steels are available.

 

Accordian reeds can be "sweet," indeed the word "sickly" comes to mind. I suspect the accordian reed makers carefully choose their steel to achieve this.

[JimLucas]

I wonder what kind of brass "brass reeds" are actually made of?

A friend once made me some small sheets of "reed brass", which he alloyed using a formula from a 19th century technical book. I rather doubt that it was exactly the same formula as any used by the concertina makers, though I have made a couple of reeds from it.

 

Unfortunately, I have totally lost touch with him, and I have no idea what the formula was that he used. For the very patient digger, though, there must be books with such formulas in many a university library.

 

Copper alloys generally have a much worse tendency to creep (which translates to go out of tune) and suffer fatigue failure (ie break in response to a large number of flexes) than equivalent types of steel.

This is something the old brass-reeded instruments are infamous for.

 

Some of the 20th-century Wheatstones are listed in the ledgers as having "non-ferrous" reeds, but unfortunately nothing to indicate just what sort of alloy they might be.

 

Beryllium copper is a superior modern spring material, for example.

Beryllium is quite toxic, and I don't think one should use a file to tune beryllium-brass reeds without first booking a hospital bed. From The CRC Handbook of Chemistry and Physics comes the following quote: "The metal, its alloys, and its salts can be handled safely if certain work codes are observed, but no attempt should be made to work with beryllium before becoming familiar with proper safeguards."

 

I suspect that historically the steels used for steel reeds would be so-called "spring steel",...

Spring steels were certainly used in making concertina reeds, but there were various different grades used at different times -- and probably even at the same time -- by different makers. One craftsman once remarked to me that he could retune 5 Lachenals using a single file, but only 1 Wheatstone before the file wore out.

 

But there are others here who know much more about this detail than I do, and rather than speculate, I will ask them to jump in.

[Stephen Chambers]

They didn't have plastic either, I would point out to the person who suggested that Lachenal "bone buttons" might be plastic.

Actually, they did.

 

Lachenal's started to make buttons from erinoid (a type of casein), in the late 1920's. Wheatstone's started to use it in 1933 (it is recorded in their ledgers, as "Erin"). Crabb's also used it in the '30's.

Edited April 11, 2004 by Stephen Chambers

[Theo]

Is there any material which has been used for reeds which offers the sweetness of the brass reeds without the drawbacks (falling out of tune and breaking)?

 

There is nickel, which seems to have been used only in the early days of concertina manufacture. Quite by chance I hace seen two early English system instruments recently with nickel reeds. They have a similar tone to brass, but louder though without the hard-edged sound you get with good steel reeds. They appear to be even less subject to corrosion than brass. The ones I have seen still looked bright and shiny after a century and a half. Whether they are any less prone to break I have no idea.

 

There must be some reason why brass and steel took over. Possibly manufacturing reasons - I have a suspicion that nickel can be a difficult metal to work.

 

Theo

[d.elliott]

There is nickel, which seems to have been used only in the early days of concertina manufacture. ... ..  They appear to be even less subject to corrosion than brass. The ones I have seen still looked bright and shiny after a century and a half.  Whether they are any less prone to break I have no idea. 

 

There must be some reason why brass and steel took over.  Possibly manufacturing reasons - I have a suspicion that nickel can be a difficult metal to work.

.

I have tended to assume that the 'brass' used for brass reeds was probably more akin to a bronze if only because of its colour, certainly there must have been other alloying elements in it, I may be able to find out more through some new contacts at work.

 

As to nickel, certainly these days very expensive, and some of the nickel alloys are 'impossible' to work, certainly in their treated condition. I would suspect that the nickel reeds were reasonable to work, but cost would have been an issue. This, combined with improving carbon steel production and metallurgical controls, particularly cleanliness would have made nickel a less attractive option.

 

I am intrigued by the thought of the Aerospace Company contact mentioned earlier, that industry uses titanium, nickel alloys like 718 and high temp stainless, super high strength steels like 300M as well as the aluminium alloys and bearing materials etc. Very interesting! Would this contact be for reed tongus or frames????

 

Dave

[JimLucas]

I am intrigued by the thought of the Aerospace Company contact mentioned earlier, that industry uses titanium, nickel alloys like 718 and high temp stainless, super high strength steels like 300M as well as the aluminium alloys and bearing materials etc. Very interesting! Would this contact be for reed tongus or frames????

Dave has now stimulated my own curiosity with regard to consulting Aerospace metallurgists. Surely they have great experience and access to technology, but I thought their main focus -- aside from strength -- was on reducing vibration, not improving it.

[d.elliott]

Jim, thinking about what one would want from reed materials:

 

Frame:

 

stability, corrosion resistance, low mass, ease of cold punching, or perhaps broaching, low cost, so: low proof stress, lowish hardness, low densityand not too expensive. Sounds like an aluminium alloy rather than titanium?

 

Reed tongue:

 

corrosion resistance, good fatigue properties, significant mass, ease of machining and filing, good elastic properties, so: medium hardness, moderate proof stress, high density. Sounds like an austenitic stainless?

 

Dave

[JimLucas]

...thinking about what one would want from reed materials:

Frame: ...Sounds like an aluminium alloy rather than titanium?

I'm no expert on metallurgy, but that sounds reasonable to me. Before such aluminum (note US spelling ) alloys existed, though, maybe brass was the best match to those criteria? Oh yeah, that's what they used.

 

Reed tongue: ...corrosion resistance, good fatigue properties, significant mass, ease of machining and filing, good elastic properties, so: medium hardness, moderate proof stress, high density. Sounds like an austenitic stainless?

The "medium hardness" property seems to have been abandoned in building what many consider to be among the best instruments... Jeffries and high-end Wheatstones. Maybe "ease of machining and filing" was not considered as important as some aspects of the behavior of the finished reeds? Or maybe those are still at what you would consider "the hard side of medium", and what you would consider "hard" would be too inelastic for reeds?

[Henk van Aalten]

Frame:....Sounds like an aluminium alloy rather than titanium?

 

Reed tongue:.... Sounds like an austenitic stainless?

What about thermal expansion? When there is a difference in expansion coefficient you could have reed(end)s that touch the frame, or to much space between reed and frame. Think of a "playing-temperature" between -10°C and +40°C... or am I worrying too much .

[Clive Thorne]

Frame:

 

stability, corrosion resistance, low mass, ease of cold punching, or perhaps broaching, low cost, so: low proof stress, lowish hardness, low densityand not too expensive. Sounds like an aluminium alloy rather than titanium?

Dave,

 

A couple of thoughts:

 

Would punching or broaching still be today's prefered manufacturing method? I would have thought that laser cutting would be an option, in which case the classic machining/forming properties would be less important.

 

If a stronger materail was used (eg titanium, stainless steel), then a smaller reed frame could be used so the mass of the reed frame would not nessecarily go up in proportion to the density.

 

I've always had a gut feeling, totally unsupported by evidence, that the weight of the reed frame would have an effect on the tone of the instrument.

 

Just some thoughts, I'd be interested in your comments.

 

Clive.

[d.elliott]

Clive, too much wine with the Easter dinnner to reply fully,

 

lazer precision? I have +/-0.005" in the back of my mind, not really good enough for frames.

 

size of reed is dictated by the mass/ relative stiffness of the reed tongue, not the reed frame, hence my thought that Ti would be no good for the tongue, too light for its strength

 

There has been much debate about the implication of reed frame weight on sound tone & harmonics, usually in the brass v ally game. I tend to feel that you are right, but having played both brass and ally framed machines of similar vintage and same manufacturer I don't recall any notable differences.

 

perhaps Geoff Crabb could comment???

 

Dave

[mike byrne]

Dave,

 

I have a 30 button Lachenal Anglo with steel reeds in steel reedframes, its No.189667.

 

The ends are mahogany, a bit fancier than normal but not as intricate as the rosewood ended models.

 

The reeds and frames were both rusty but now it's been de-rusted and tuned the sound seems more strident than a brass framed equivalent.

 

Mike

[Stephen Chambers]

I'm no expert on metallurgy, but that sounds reasonable to me.  Before such aluminum (note US spelling  ) alloys existed, though, maybe brass was the best match to those criteria?  Oh yeah, that's what they used. 

Aluminium (note correct spelling ) frames were first used, in the 1890's, to build lightweight, top of the range, models (it made it possible for a 63-key Edeophone to weigh no more than a regular 48-key). However, the metal used in those early instruments was too pure, and tended to corrode badly, so much so that I have seen examples that had been rendered unplayable because of the build-up of white, powdery, oxidation on the reedframes.

 

Later instruments have employed an aluminium alloy, called Duralumin (patented, by German metallurgical engineer Alfred Wilm, in 1909), with much greater success.

 

Brass has always been considered superior, for tone and response.

Edited June 15, 2006 by Stephen Chambers

[Richard Morse]

Would punching or broaching still be today's preferred manufacturing method? I would have thought that laser cutting would be an option, in which case the classic machining/forming properties would be less important.

We're finding that laser cutting is a reasonable method for making reed plates. The tolerances our laser jobber does is about .0002", which seems accurate enough. The main problem is the diameter of the cut which is telling at the corners - they aren't crisp as they have a .003 radius (but is still manageable/acceptable if you ease the corners of your reed tongue), and that the initial "plunge" ablates more material so we make sure that that start is at the root (or butt) end of the vent (frame opening).

 

If a stronger materail was used (eg titanium, stainless steel), then a smaller reed frame could be used so the mass of the reed frame would not nessecarily go up in proportion to the density.

Smaller (thinner) isn't necessarily better. The depth of the frame is key to response and volume propagation.

[Clive Thorne]

The tolerances our laser jobber does is about .0002",  which seems accurate enough.

 

.....

 

and that the initial "plunge" ablates more material so we make sure that that start is at the root (or butt) end of the vent (frame opening).

 

......

 

Smaller (thinner) isn't necessarily better. The depth of the frame is key to response and volume propagation.

Richard,

 

I'm very pleased that you are using laser cutting for the reed plates, having worked for a laser company (GSI-Lumonics) for 5 years (10 years ago!), I always thought it would be a a viable option. The tolerance you quote more in line with what I would have expected (better even) that the 0.005 that Dave had in mind. A lot of it comes down to the type of laser you use of course.

 

Do you also use a laser for the fretwork?

 

 

Regarding the initial penetration, it is very common practise to do this within the area you are going to cut out. Ie, penetrate, move out to the required line, cut the shape, with a little overlap, move in from the edge slightly and stop cutting.

Even better if you can arrange the lead in and lead out to be arcs, so you don't get any enlargement due to the momentary slowing down.

 

 

When I said smaller I meant side to side rather than thickness.

 

 

Clive.

[Richard Morse]

I'm very pleased that you are using laser cutting for the reed plates, having worked for a laser company (GSI-Lumonics) for 5 years (10 years ago!), I always thought it would be a a viable option. The tolerance you quote more in line with what I would have expected (better even) that the 0.005 that Dave had in mind. A lot of it comes down to the type of laser you use of course.

I've learned a lot about lasers since we started producing concertinas. Currently we use lasers to cut the fretwork, action board, and action levers (Albion model only - our Ceili uses brass rod levers). Soon we'll be using lasers to cut the chambers and pad pans as well (now in the testing stage). We'll also be using lasers to cut our reedpan/shoes for our Hayden model which have turned out well (using a 5-axis laser!).

 

Due to the differences and thicknesses of the above materials, and to the various types of lasers and setups the jobbers have, we are working with 4 different laser companies.... For each of our situations we needed a specific laser power, travel speed, focal length, etc. Sometimes the environment is special too as some of the wood cutting lasers needed to cut in a non-oxygen environment.

Regarding the initial penetration, it is very common practise to do this within the area you are going to cut out. Ie, penetrate, move out to the required line, cut the shape, with a little overlap, move in from the edge slightly and stop cutting. Even better if you can arrange the lead in and lead out to be arcs, so you don't get any enlargement due to the momentary slowing down.

That's exactly what we do. The jobbers here call it "pig-tailing". There's a surprising amount of exactingness around it as not only do I have to CAD everything just right, but talk through many of the cuts with the jobbers to make sure they cut in the right direction and with the correct offset (to account for the beam diameter) on the correct side of the CAD line.

[Charles_Mackay]

For those curious about the composition of brass reeds this would probably be quite easily solved if they were sent for elemental analysis by ICP emission spectrometry or X-ray fluorescence. Most university Chemistry departments with decent inorganic analysis capability should be able to do this, or alternatively, I suspect that certain of the Public Analyst services in the UK could do it. I feel almost certain that the Laboratory of the Government Chemist (LGC) (in the UK) would have this capability.

 

Carbon content in steel reeds might be a bit trickier though.

 

Problem is both cases is that it would require sacrificing a reed since good quantitative analysis is more readily done in solution. If anyone knows a better way please say.

 

And then there's the cost aspect........not huge but not trivial.

 

Charles Mackay