40 Button Lachenal Anglo Restoration

I recently fully-restored a 40-button Lachenal Anglo. It was in pretty poor condition when I received it. The wooden ends were non-original, damaged, and not very well made.


The bellows may have been original, but they were worn-out and patched.

There was significant damage to the woodwork, including a couple of split reed chamber walls.

The pads were mostly dust held together with blobs of sealing wax, and the springs were mostly non-original and much too strong, probably in a vain attempt to make the knackered pads seal.

Step 1: remove the old bellows.

The bellows frames weren’t too bad underneath, apart from a few loose/missing corner blocks.

Next I dismantled the actions, laying the levers out on a piece of card so I could figure out which was which when it came time to reassemble the instrument. Quite a few of the action box walls had come apart at the glue joints, but the wood wasn’t too damaged.

Most of the end bolts and corresponding nut plates were worn out, probably due to somebody over-tightening them in an attempt to make the instrument airtight (unsuccessfully, because the various boards had all warped).

I already wrote an earlier blog post about making the new end bolts. I also made and fitted a new set of nut plates from thicker brass (3mm rather than 2mm), so they will hopefully be less prone to stripping in the future. The new wood screws are stainless steel and slightly longer than the originals. I plugged up the old screw holes with matchsticks before fitting the new screws.

The end bolt holes in the action box walls were worn oversized (particularly at the tops, where the screw heads had sunk through the end plates and worn a deep gouge), so I plugged them all with beech dowels.

I glued the walls back together in a band clamp using hot hide glue. Unfortunately the top and bottom halves didn’t quite match up perfectly, which I later realised must be because they originally came from different instruments (they are a different wood, and the pad gouges on the inside of the top walls don’t marry up with the positions of the pads).

I used a simple jig to re-drill the end bolt holes a consistent distance from the outside of the instrument.

Then I clamped the bellows frame to the bottom half of the action box and drilled the tapping holes in the nut plates.

Once I’d got a couple of them drilled, I used spare drill bits to keep them aligned to each other while I drilled the other four.

I took the plates off again to tap them, to avoid embedding a lot of greasy swarf inside the bellows frames for perpetuity.

As I mentioned previously, two of the reed chamber walls had split. I could have attempted to glue them back together but I doubt it would have held up for long, so I unglued them (hot water to soften the hide glue, and waggling until it suddenly came free like a loose tooth).

I glued new quartersawn sycamore walls in place, with hide glue again, using the reed as a wedge to hold it in place while the glue dried.

One reason why this wall was weak was that part of it needs to be cut away to make space for the valve in the next-door chamber. I thought it best to chisel this out in-situ.

I used a combination of needle file and skew chisel to undercut the new wall for the dovetailed reed slots.

Both the action boards were badly warped, so they didn’t seal properly to the tops of the reed pan walls. I cured this by painstakingly lapping them using a sheet of sandpaper glued to glass. I don’t seem to have a picture of it, but I also inlaid a piece of sycamore to repair the deep gouge visible in this one where the sound post screw goes through it.

On the right hand reed pan, it was so hollow near the sound post screw hole that I decided to glue a piece of veneer to the area to build up the thickness before lapping most of it away. This incidentally also filled in the oversized gouge around the screw hole.

The reed pans were warped too, though sadly not in a way that matched the warping of the action boards, so I also had to lap the tops of the walls. To avoid removing too much depth from the chambers, I had to glue tapered shims to the tops of about half of the walls near the outer edge.

After getting the tops of the reed pans flat, I replaced all the support blocks in the bellows frames. This is far easier to do without the bellows in the way, hence why I did all the above work prior to making the new bellows.

This shows why you sometimes find a block or two that isn’t right in the corner of the bellows frame.

The woodwork repairs done, I made and fitted new chamois leather gaskets. Not pictured, it was necessary to fit card shims to the inside of the bellows frames before the chamois to get the pans to fit tightly.

I have recently bought an old picture framing mat board cutter. This tool makes it much easier to cut the bellows card into strips, bevel the top edges at 45°, and with a simple jig, cut the strips into individual cards. Incidentally I switched from 1.5mm thick greyboard to 1mm thick millboard. It is a little more flexible but the reduced thickness really makes the bellows feel a lot less bulky. I think it’s a better quality material too, and likely to last longer.

After my experiment with self-adhesive hinge linen on the last set of bellows, I went back to Fraynot linen cut on the bias, attached with a bookbinders’ starch paste. The resulting hinges are thinner and much more supple.

Because I originally made my bellows mould to fit a set of bellows that came off a 6″ instrument, and this was a 6 ¼” instrument, I had to pack them out a little using strips of thin plywood between the core and the forms.

This time I prepared all of the leather parts before starting to glue them on. I also refined the shape of the gussets a little, and skived most of the parts slightly thinner than on previous bellows.

The bellows immediately after taking them off the mould! They are initially quite stiff and need to be broken in. In order to maximise their useful range, I spent the next few weeks while I was working on other parts of the restoration alternating between squeezing them fully closed in my bellows press and stretching them fully open using a couple of the forms from the bellows mould, exercising them a bit every time I handled them. I think this treatment along with other improvements really helped; the finished bellows are the most supple I have made to date.

A set of reproduction Lachenal bellows papers really helped them to look the part.

I recently bought a small Eclipse fretsaw frame that is the ideal size for concertina ends; much less tiring to use than a standard large fretsaw frame. I had to make new blade clamps because the old ones had stripped threads. I made the new clamps from scraps of tool steel and hardened them, so they ought to last pretty much forever now! I also made a new saw table with a nice big flat rigid top.

This shows why I made the top of the saw table so high; I prefer to do piercing standing up, and this height results in my arms being in the most comfortable position.

I cut the new ends from 22 S.W.G nickel silver (German silver) sheet, starting by roughly cutting them out oversize with a slitting blade in an angle grinder.

The fretwork design is based on photos I found online of a vintage Lachenal 40-button, but I redrew it and modified it a little (eliminating the redundant unused button holes on the opposite side from the thumb button on each side).

I drilled all the holes first. The bolt holes are actually transferred from the action box frames, not the template. I later realised the button holes should have been a bit larger to give more clearance around the buttons, so I had to enlarge them after I had cut all the fretwork.

Piercing in progress. I actually find this one of my favourite parts of the job; my mind goes into a flow state, and when I emerge some hours later I have made a beautiful thing.

I’m going to skip over a few days of toolmaking here; I may come back later and write a separate post about it. I made a press tool modelled on the one used by the Crabb company, which crimps the edges of a metal end plate one side at a time.

The side on the left has been crimped, the tool is about to press the side in the middle:

After pressing:

The end result. I found I had to do some manual cleanup work to neaten it where it hadn’t worked perfectly, particularly in places where the piercings were quite close to the border.

I polished the finished ends using my Bridek polishing spindle and various Menzerna compounds.

The button peg holes in the action boards were both worn oversize, and probably no longer exactly aligned with the button holes in the new ends, so I decided to plug them all with beech dowels and re-drill them.

I made this tool to drill the button peg holes; the brass bush is the right size to slide in the button hole and guide the drill bit to the right location in the action board. I used the depth stop on my drilling machine to make sure I didn’t quite drill all the way through the board.

You can see in this one that the new holes are sometimes slightly off from where the old ones were; if I hadn’t re-drilled them, the buttons wouldn’t have lined up right, which would probably have caused them to stick.

In order to bush the button holes, I needed to screw a piece of plywood to the underside of the end plate so I could glue the bushes into that rather than trying to glue them directly to the thin metal. (I later cut the board to match the fretwork.)

A different special tool used to accurately locate the pilot holes in the bushing board.

I fitted loudspeaker grille cloth below the fretwork. It proved a bit tricky to get the button holes in the right places; I settled on making a card template, then placing the template over the fabric, cutting around it with a rotary cutter, and punching the holes through the card and fabric both.

I glued the fabric to the underside of the metal with PVA (rather a fiddly job to avoid baggy areas or holes not lining up). One side-effect of this was that the acidic fumes given off by the glue oxidised the polished surface of the metal, and of course I couldn’t just take them back to the polishing machine because it would probably damage the cloth. I managed to clean it off with dry jewellery polishing pads but it was a bit annoying. Perhaps epoxy would be a better choice.

I laser-printed a replacement maker’s logo on archival paper and stuck it on with PVA.

This is a taper reamer I made from silver steel to slightly taper the holes in the bushing boards. By making the holes looser at the bottom than the top, they are better able to cope with any slight misalignment than if the sides of the holes were parallel.

Similarly, I made a new bushing reamer that is continuously tapered, thus making the bushes looser at the bottom. You can also see in this picture that I cut the boards closely to the outline of the fretwork and coloured the edges black so you can’t see them under the grille cloth.

Lachenal action levers sometimes wear in a way that causes them to twist as they pivot, causing uneven movement and pads not seating properly. The way I fix this is by building up silver (hard) solder on the worn area of the lever, then filing it back until it fits well again. Usually the post isn’t badly worn enough to need the same treatment. I had to do this repair to about half a dozen of the levers on this instrument.

Cleaned and rebuilt actions, with new springs, bushes, dampers, pads, etc.:

My first attempt at the elongated air hole pad was to cut it from the same leather/felt/card sandwich as the ordinary pads. It sort of sealed, but would leak when you pressed the bellows hard. I worked out that it was because the card was too flexible; the ends of the pad were flexing up and letting air leak out. I fixed this problem by making a special pad with a top layer made from thin stainless steel sheet instead of card.

Skipping over a bunch of toolmaking again; I made a set of dies to punch my own valves to a consistent range of sizes. I also got hold of some special thicker (very expensive) leather that is better-suited for the largest valves. I made the new valve restraint pins from 24 S.W.G. stainless steel spring wire. I have switched to using gum arabic to glue the valves to the reed pans; it is plenty strong enough when dry, easy to use and non-messy, and very easily removed with a little warm water on a cotton bud when you need to replace a problematic valve. I lightly cleaned all the reeds, and where necessary shimmed the slots in the reed pan to get the reeds to fit snugly.

The strap-adjuster thumb screws were the wrong ones for the instrument; the thread didn’t fit the captive nuts. To cut a long story short, I decided to make all new nuts and screws with an M3 thread.

Luckily I was able to reuse the tiny wood screws; finding replacements for them might have been tricky.

I’m quite proud of these thumb screws; it may seem like a trivial detail but the first ones I made were pretty bad in comparison, and I really think I have got the hang of them now. If you dig back through my Instagram page, somewhere in there is a post describing my process.

There’s quite a bit going on in these next two pictures. Firstly, notice the bottom half of the wall is ebony (original to this instrument), the middle section is mahogany (probably came from a different vintage instrument), and then there’s what appears to be another ebony section between the mahogany and the metal plate. I needed to add the second black section as a spacer to make the boxes a bit deeper, because the action levers were hitting the bushing boards. It is made from a manufactured ebony substitute called Rocklite Ebano. Although I needed to do this for mechanical reasons, I actually think the three-layer effect looks quite unique and attractive.

Secondly, I sanded and lightly French-polished the woodwork. I deliberately didn’t go overboard building up a high gloss, and I tried not to remove too much of the old patina in the process.

Thirdly, I made new brass strap rings (the loop thing that holds the strap down to the thumb rest), replaced the captive nuts in the ends of the handles with M3 ones, and made domed brass washers to hold the fixed end of the straps.

Fourthly, I made new leather hand straps. I don’t think I’ve quite got the pattern perfect yet (the ‘tails’ are about an inch too long), but I have figured out how to round and smooth the edges using an edge beveler and a burnishing spindle so they feel more comfortable on the hands.

When I received the instrument it was in C#/G#, old philharmonic pitch, which is about half a semitone higher than modern concert pitch. In consultation with the client, we decided I would re-tune it up to D/A concert pitch. Actually, I later realised that it may have originally started out as D/A old pitch and been tuned down to C#/G#, because the note stamps on the frames made more sense if that was the case. Most of the reed tongues were steel but there were a handful of brass ones in there too; you have to be very gentle with them as a tiny amount of filing can cause a big shift in the pitch, much more so than with steel ones.

The highest reed on the instrument was missing. I worked out from button charts that it was supposed to be a very high F#. I made a replacement, making an educated guess as to the length of the vent. It was so small that I didn’t have an end mill that could cut the vent slot so I did it by hand with a jeweller’s saw and tiny files (not as difficult as it sounds, though a little time-consuming to get it perfect). After experimenting with the profiling for a while, I managed to get it sounding remarkably well on the tuning bellows. Unfortunately once in the instrument, this reed, along with the other three or four highest notes, were pretty unresponsive, needing quite a high bellows pressure to get them to start. After quite a long time spent experimenting with them, I came to the conclusion that the problems mostly came down to the reed chambers being too large.

The worst one would barely speak at all (the one on the bottom side of this chamber; it is quite a lot higher in pitch than the corresponding top-side reed). I managed to significantly improve it by replacing the end wall with one closer to the vent slot so as to reduce the chamber volume.

My highest reed was in an inboard chamber. I managed to improve its response by making a little removable block that significantly reduces the dead volume in the chamber.

The finishing touch was to add my mark to one of the reed pans.

I had one or two bits left over after I finished putting it back together!

The finished instrument (photo courtesy of the instrument’s owner, Wallace Calvert). I am particularly proud of how nicely the new end plates turned out.

And now for a special treat, here is a clip of Wallace playing The Humours of Tullycrine on the instrument:

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Turning End Bolts

On my first instrument, the ends were held on with commercially-made stainless steel allen-head M3 screws. They work fine, but I felt they gave the instrument a bit of a modern, almost industrial look.

I am currently working on restoring a vintage Lachenal Anglo for a client, and the end bolts and captive nuts are missing or badly worn due to past over-tightening (probably from trying to cure leaks that were actually due to internal structural problems). Needless to say, it wouldn’t have been appropriate to replace them with modern screws. Rather than try to source a better second hand set from a parts dealer, I decided it was time to figure out how to make my own new brass end bolts from scratch.

I sourced some 4.5mm diameter free-machining brass bar. The finished heads want to end up about 4.5mm, so I need to avoid turning it any smaller in the process. It came in 330mm lengths, which I figured out would comfortably make eight bolts if I cut it into four sections.

One bit ended up too short due to a mistake. Incidentally I used to think junior hacksaws were rubbish until I got some better quality Sheffield-made blades and found this excellent frame for a pound at a car boot sale. It tensions the blade really tight, which prevents it flexing in the cut, and the aluminium handle is really comfortable.

If I’d only been making a small number of them I probably would have held the blanks in the three jaw scroll chuck and accepted that they would turn out slightly non-concentric, but since I needed to make a large batch and will be making more in the future, I decided I wanted to use a collet instead. Taig (the manufacturer of my lathe) sells a few standard imperial-size collets, and blanks that you can drill to whatever size you want. I’ve had this lathe for probably fifteen years and this is the first time I have ever used one of the blank collets! They are made from a nice free-machining steel that drills very easily:

The difficult part is holding the awkwardly-shaped piece of metal while you cut the slots in it. I settled on putting a piece of the 4.5mm brass in it, and holding that in the vice instead of the collet.

Once I had sawn the first slot, I turned it 90° and used the slot in the brass bar to guide the saw while I cut the second slot. Then I flipped it over and cut the other two slots.

The finished collet. Not too bad for a junior hacksaw.

The first step in machining the bolts was to put the blank in the collet with enough protruding for a single bolt, then turn down the shaft to 2.25mm. Before doing the job, I spent a long time worrying about how I would do this without the shaft flexing away from the tool towards the end, resulting in it getting fatter towards the tip. This wasn’t as much of a problem as I expected it to be. Getting the tool bit really sharp and running the lathe at its maximum speed was a good starting point.

The first method I found was to turn the first third of the shaft to finished diameter a bit at a time, then move along and turn the second two thirds to finished diameter. This worked fine but took a couple of minutes per bolt. I found I could take heavier cuts on the second section, then I got to experimenting to see how far I could push it, and to cut a long story short, it turns out that it’s perfectly possible to turn the entire thing to finished diameter in one pass! Once I figured this out, it sped things up quite a lot. It’s important that you do it in one pass, because you need the full diameter of the bar to the left of the tool to support the cut. If you try to do a second cleanup pass, however light, the bar will flex at the end. Here’s a video clip to prove it:

Next I used a fine single-cut file to put a blunt point on the shaft.

Then I used a tailstock die-holder and a good quality sharp HSS die to cut the threads. I used a dab of cutting oil (it really makes a noticeable difference to how easily the die cuts) and turned the spindle by pulling on the drive belt, using a ruler to measure when the tailstock had moved far enough for the desired length of thread. The video above also shows the thread cutting operation.

A brief digression about the threads: the original Lachenal bolts are about 2.25mm major diameter, but a relatively coarse pitch. I haven’t been able to find any standard thread that matches it. Since I don’t have a screw-cutting lathe, to copy it I would have had to commission a specially made tap and die set, which would have been very expensive. I instead decided to use 8BA, which has the same diameter but a finer pitch. I don’t think this is a problem for the restoration because I am replacing all the bolts and captive nuts at the same time. From what I have read, the Crabb company used 8BA bolts in their instruments too.  BA threads are mostly obsolete now apart from a few niche applications, but you can still get hold of new taps and dies for them.

After doing all the above steps to one end of the blank, I turned it around and did the same to the other end. I probably could have used slightly shorter blanks, it just worked out this way when I cut the bar stock into four.

Next I needed to cut the piece into two and form the domed heads. To do this efficiently I got a ¼” HSS tool blank and ground a special profile onto it. This profile first parts off the stock to length, then you carry on plunging it and it forms the domed shape.

Here’s a video of the process showing how quick it is:

Next I cut the slot in the head using a HSS slitting saw, 50mm diameter by 0.6mm thick with 100 teeth. I didn’t have a mandrel with the right centre diameter, but Taig sells blank mandrels that screw onto the headstock so you can turn a custom spigot to fit your saw blade. Luckily I have an older-model Taig milling machine that has the same headstock on it as my lathe; newer mills come with an ER16 collet chuck instead, which makes this sort of thing a bit more complicated because you can’t just transfer something straight from the lathe headstock to the mill.

A nice snug fit on the mandrel:

Next, I needed to make a special fixture to hold the bolts on the milling machine while cutting the head slot. I made the top part from aluminium, and the nut bar from mild steel. Tightening the set screw clamps the shaft of the bolt tightly.

The slitting setup on the milling machine:

Here’s a quick video clip of it cutting a slot:

Slitting the head of the bolt. #cncmilling #taigmill #concertinamaker

A post shared by Alex Holden (@alexholdenmaker) on

Although I did it with a short hand-written CNC program because I have a CNC mill, this operation would be dead easy on a manual mill or even a milling attachment on the lathe. I found that with the CNC mill, I could load a bolt in, hit Start, go back to the lathe, turn the head on the next bolt, and return to the milling machine around the time it finished cutting the slot.

Next I put the bolt back in the lathe and used 800 grit emery paper and the top speed to smooth out any tool marks and burrs.

Finally to the polishing spindle to give the head a shiny finish. This Menzerna 480W compound is very effective on brass.

I had to use a screwdriver to clean excess polishing compound out of the slot of each one.

Here’s the first one I made between a couple of different ones from the vintage Lachenal. My head is more closely based on the shallower one on the right.

I made a batch of about seventy bolts; enough for the Lachenal restoration and my next few instruments.

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Brun Addendum

My use of a working title to describe my first instrument in the past few blog posts was causing a little confusion, so I have now chosen an official name for the model: the Holden Concertinas Brun.

The name comes from the River Brun, which most historians believe my home town is named after (Brun Ley over time became Burnley)1. The name of the river may have come from the Old English word Brún, which is an adjective meaning, “brown, dark, dusky; having metallic luster, shining.”2

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Brun Part 8: Conclusion

It has been a long and at times bumpy journey with a successful arrival at the end. I have produced a good quality, attractive, playable instrument, where I made every part myself except the reed clamp screws and end bolts. I have learned or improved many skills along the way: CNC, toolmaking, metalwork, woodwork, leatherwork, French polishing, tuning, and so on. Where I made mistakes along the way, I have learned from them, and I am certain #2 is going to be even better. The instrument is currently away being evaluated by an expert and I have already heard some encouraging feedback. Hopefully at some point I will be able to post links to reviews and videos of it being played.

What’s next? I am in the early stages of designing and tooling up to make a pair of new instruments, both of them fairly traditional 6 ¼” hexagonal Anglos, one with wooden ends and one with metal ends. A bit further down the road I have plans for a larger and more ambitious Hayden duet. I am also taking on more repair work: having made a complete instrument from scratch, I am now well-equipped to take on any aspect of fixing a traditional vintage instrument.

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Brun Part 7: Reed Pans

The seventh part of the story of how I built my first concertina is about the reed pans; the removable boards that carry the reeds and valves.

One thing I have learned is that the reed pan layout is one of the most difficult and important aspects of designing a new instrument from scratch, and it has to be done in conjunction with the action board layout. It’s no good coming up with a nice logical arrangement of chambers on the reed pans, if it means some of the pad holes end up underneath the keyboard, or the levers have to snake around all over the place to reach the appropriate pads, or you have to use levers that are too short to operate smoothly. Sometimes you have to compromise in one area or another, either in the reed pan (e.g. making reeds smaller because there isn’t room for the ideal size of chambers), or in the action (e.g. making two levers cross over each other or bend sideways).

This being my first instrument and a brand new design, I spent several days at the design stage figuring out a good compromise. When I began the process, I wasn’t even sure how many buttons I was going to end up with (the design brief specified the overall size of the instrument, to include as many buttons as practical in that form factor). The design I came up with looks pretty simple and logical, however in order to reach it, I tried and discarded a number of more complex arrangements. The three main compromises I ended up making were that a few of the levers are shorter than ideal (those buttons feel a bit stiffer than their longer neighbours); six of the chambers are in the centre of the instrument (for reasons I don’t fully understand, they sound a bit less good than chambers on the outside – this is a well-known phenomena in the concertina world); and I was forced to abandon the idea of including an air button.

You might find it interesting to take another look at the photos of Wheatstone’s Duett concertina of the 1850s. My Brun is the same size but with an extra three buttons per side. To achieve that, I went with a similar reed pan arrangement but with a second, smaller pan on each side. Wheatstone’s had one pan with two rows of six chambers; mine has a pan with two rows of five and a second pan with one row of five. Five columns is actually a fairly tight fit in the available width. I tried fitting in six and it was ridiculously tight: I suspect Wheatstone must have used narrower reed frames and smaller diameter pads, which probably had a negative effect on the sound it produced. My actions are a more conventional riveted lever type, and I suspect are probably more comfortable to play.

My first idea for making the reed pans was to mill them from thick pieces of birch plywood. This didn’t really work, because the chamber dividing walls were too weak due to the cross-grain layers, causing them to break during the machining process.

Plan B was to mill them from solid quartersawn sycamore. Using quartersawn wood means it will move and warp less due to changes in humidity level. The little bandsaw I had at the time was just barely powerful enough to rip the slab I had in the thin dimension.

Looking at the end grain, you can see it is reasonably quartersawn towards the bark side of the piece. Because the pans only needed to be a little over 4″ wide, I was able to pick the best section.

Planing one face true.

The bandsaw was never going to resaw the full width of the board, so I had to do it by hand. Step 1 was to make a kerfing saw; a special tool that cuts a shallow kerf at a specific distance from the face of the board.

This kerf was then used to help guide the path of an ordinary rip saw.

Here are the two roughly sawn reed pan blanks, with the rip saw I used behind them. I’ve since got a bigger rip saw with coarser teeth that would have made the job a bit easier, but it wasn’t too bad really because the boards are so small.

At this point I put the blanks on one side and started recording their weight once a day. Although this slab was supposedly kiln dried before I bought it, it still seemed to have a higher than equilibrium moisture content inside. They lost a few grammes of moisture each over the first few days, and warped a little too. After a couple of weeks they stopped losing weight, so I felt they were probably stable enough to carry on working on them. First I planed one face of each flat and smooth (this face was to become the bottom of the pan) and ripped them narrower, being careful to follow the direction of the grain as closely as possible.

I left the other face alone because I planned to use the milling machine to flatten it, thus getting it very accurately parallel.

Problem! When I mounted the blank on the milling machine, the back edge fouled on the bottom of the Z axis slide before it was far enough back for the cutter to reach the front of the board.

The solution was to make a thinner fixture that (just) allowed the blank to fit under the Z slide. The two small holes in the middle of either end match with registration pins in the spoilboard, thus allowing the blank to be flipped over and still be in the same position, so the bottom reed slots end up in the right place relative to their chambers.

Oops. I did something stupid in zeroing the Z axis and plunged the 1/2″ end mill a few mm deep into the first blank. This could have been a major setback as I didn’t have a spare blank prepared, but luckily I managed to reposition the pan on the blank such that the damage was in an area that was due to be milled out anyway.

After truing up the top surface, I flipped the piece over and cut the bottom slots. There needed to be little pockets next to each dovetail slot for the dovetail cutter to start in, because the tool isn’t designed to be able to plunge into the work. I cut the wind slots for the bottom reeds at the same time as the dovetail slots, to ensure they are perfectly aligned with each other.

Bottom reed slots cut.

Back to the top again. I cut the outsides of the pans before the chambers, but not all the way through the board, because this reduced the amount of stress on the dividing walls. This picture shows how I managed to position my previous accident inside a region that was due to be removed.

Both reed pans fully routed. The left hand one is off-centre because of the previously mentioned repositioning.

This picture shows a few interesting things. In order to fit the reeds in as tightly as possible, the frames overlap, but not quite enough for a dovetail slot to break into the opposite side’s wind slot. They also undercut the walls slightly, more so at the outside edge (because the frames are tapered). Thirdly, I tried something new here that I haven’t heard of any other maker doing in this way: I made the chambers different depths, based on a ratio of the chamber length. It was common for English concertinas to have sloping pans, where the chambers at one end were deeper than at the other, but that only really works when it’s possible to arrange the pan in such a way that the pitches gradually increase from one end to the other. The way I did it here, it was possible to have a deep chamber right next to a shallow one (the first and second chambers are an octave apart).

The inner walls of the bellows frame are tapered to get a good seal, so I had to cut a matching taper on the outsides of the reed pans. The side walls I was able to do on the shooting board with a shim to tilt it up.

I daren’t try to use the shooting board to plane across the ends of the chamber walls, so I used the linisher for that instead.

Checking the angle with a bevel gauge.

It took a fair bit of careful work to get a good fit because the earlier problems with the frames not gluing together perfectly square meant the holes the reed pans had to fit into weren’t quite square either. In hindsight it might have been easier if I’d fit the pans to the frames before I put the chamois leather gaskets on the frames, and it definitely would have been much easier to do it before attaching the bellows to the frames.

If you’re familiar with more conventional concertina reed pans, you’re probably wondering at this point how you pull out the reed pan (which tends to be a fairly tight fit) without a hole in the middle to put your fingers through. Because I didn’t have any space for the finger hole, particularly on the left hand side, I instead attached captive nut plates on the bottoms of the larger pans and made a leather handle that screws onto the pan.

Once you have lifted out the larger pan, you can put your fingers through the hole and push out the small pan from underneath.

Here’s a quick video clip showing the first time the instrument made a sound:

Without the action boxes, every note plays at once. #concertinamaker

A post shared by Alex Holden (@alexholdenmaker) on

When I made the bellows frames I didn’t know how deep the reed pans were going to be, so I allowed a generous depth of 20mm and put off the decision until later. As it happens, I eventually made the left hand pan 18mm deep and the right hand pan 16.5mm, which meant I then had to add some sort of spacer blocks that stopped the pans going in too deep. I thought I could just make strips that went all the way around, but they fouled on the bottom reed clamps so I had to cut a lot of notches out of them. In hindsight I went about this a particularly difficult and tedious way, and on future instruments I will be reverting to the traditional-style corner blocks instead, preferably fitting them to the frames before the bellows!

Gluing strips of chamois leather to the tops of the walls with rabbit skin glue. I found that skiving the ends of these strips needs a slightly different technique to skiving bellows leather because the chamois is so soft and stretchy.

All the gaskets installed.

I made the valve restraint pins from chrome plated sewing pins. After struggling to push a few of them through the chamber walls with needle nose pliers, I found they went in a bit easier if I sharpened them on a stone first.

There’s a bit of a knack to deciding exactly where to place the pins, so as to allow the valve to open properly without getting stuck. On my next one I’m planning to try making the pins from a slightly smaller diameter stainless steel spring wire instead.

I had lots of problems with the valves. My first attempt, I cut them by hand from sheepskin skiver, and they were terrible. The leather was too stiff, and every note sounded muffled if it played at all. My second attempt, I bought a set of valves from a parts supplier, and I’m not totally sure what the problem was but they didn’t seem to want to stay flat against the pans. This photo shows how some of them have lifted up until they are touching the restraint pins. This caused a problem with the bottom few notes making a sort of ‘raspberry’ noise if you changed bellows direction while holding the button down because the valves weren’t keen to stay closed.

On advice from several other makers, I ordered some hides of Columbia Pneumatic Leather from Columbia Organ Leathers (who are based in a town called Columbia, Pennsylvania, not the Republic of Columbia). It’s not cheap but it’s nice stuff. I removed all the previous valves (I found the easiest way was to just rip them off, then use hot water to remove the remnants of the old glue) and cut a new set, mostly from the extra heavy weight hide, though I did use the heavy weight for the higher notes. It was recommended to me to wash the leather and dry it on a sheet of glass to make it a bit stiffer, but I couldn’t tell any difference before and after washing (maybe I did it wrong). For the most part, the new valves behaved much better and solved the problems I was having. A few of them misbehaved in testing, not always for obvious reasons, but replacing them solved the problem.

Here’s one of the misbehaving valves where I was able to find the cause. If I played the blow reed, then played the corresponding suck reed very softly, it would start muffled, then ‘pop’ and play normally.

It turned out I had glued it off-centre, and one edge of the valve was getting sucked down into the wind slot.

Replacing it in the correct position solved the problem. It’s quite tricky to get them positioned right because you can’t see the slot while you are gluing the valve down. I’ve considered drawing a centre line in pencil first.

The finished reed pans. Note all the marks in biro indicating where and which way round they fit.

These two pictures show the difference in size between the biggest chamber (C3) and the smallest (G5). In hindsight I suspect I could have made them all a bit smaller, but I was trying to be conservative and working on the theory that a too-small chamber will sound terrible, whereas a too-big one will just start up slowly. In fact, as far as I can tell, they all seem to respond pretty quickly.

The final thing remaining was fine tuning all the reeds, and bits and pieces of troubleshooting: tweaking the action to eliminate ciphers, replacing misbehaving valves, etc. The client asked me to tune the reeds in quarter comma meantone, with G as the root note. I made a quick video clip showing it playing a few chords, though in hindsight this doesn’t really show it off very well. You’ll have to take my word for it that it has a much nicer sound in person than recorded on an iPhone microphone. I hope at some point I’ll get to hear what it sounds like in the hands of a good player.

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Brun Part 6: Reeds

The sixth instalment in the story of how I built my first concertina is about the reeds. I’m not going to cover every step of the process because it was very similar to my previous posts on the subject, apart from a few minor improvements and the fact that I had to make sixty of them in twenty four different pitches.

Something unusual I did (it might even be the first time it’s been done by a concertina maker) is I made a different size of frame for every pitch instead of making do with a limited number of frame sizes, each one being used for two, three or even four pitches. I started by measuring the vent dimensions of the reeds in a Lachenal English I own and plotting them on a graph. They were pretty lumpy but they followed a general trend. I then fitted curves to the graph and used them to derive a formula for the reed scaling. I plugged those formulas into a spreadsheet, which calculated the vent dimensions for all the pitches I needed. The outer frames were all the same angle and tip radius, with a constant distance between the tip of the frame and the tip of the vent. A slight drawback with the way I did it is that the longer reeds ended up with thinner edges than the shorter ones; when I design the next set I may try to come up with a way to reduce that effect.

I have since learned that the reeds I based my scale on were probably what is known as “short scale”. A fellow maker sent me a set of measurements of reeds from a higher quality vintage instrument, which appears to have both longer low reeds and shorter high ones, i.e. the range of pitches is stretched out over a wider range of lengths. I understand short scale reeds were typically used when the maker needed to fit a lot of reeds into a given space, which actually makes a lot of sense for this particular instrument because the reed pans are very tightly packed. I don’t think I could have fit long scale reeds in it if I had tried. My next concertina will have the same number of buttons in a larger instrument, so I plan to use longer scale reeds in it. I have been told that longer scale reeds have better pitch stability and responsiveness, particularly on the low end.

As before, I cut the frames and clamps from 2mm brass sheet on my CNC milling machine. This time I left them at the full 2mm thickness.

When I did the prototype reeds, each frame took a very long time to mill. Before I made the first full set I spent a while experimenting with feed rates and depth of cut (wasted some material and broke a couple of end mills in the process), and came up with a reliable rate that is significantly faster than what I was using before. I also dropped what was by far the slowest part of the process: bevelling the edges of the frames with lots of tiny steps. They now come out of the milling stage with straight sides.

The full set of sixty frames and clamps, before cutting them free of the stock.

After cutting them free, I tapped all 120 clamp holes and screwed them together. The clamp is a different size for each pitch too, so it’s important not to mix them up!

I filed off the flashing and the remains of the tabs with a hand file. In hindsight it would have been quicker to use my die filer to clean up the frames, though the clamps are probably too small to do that way.

A little improvised fixture to hold each reed frame while I square up the vent corners with a needle file. It’s crucial to get the tip corners as perfect as possible otherwise you can’t get the tongue to fit really closely without clipping the frame.

The vent relief angles on my Lachenal reeds were very inconsistent and often rounded; I suspect they were quickly filed by eye without a guide. I set my guide to an angle that was roughly the average of the angles on the Lachenal reeds and used it for all of my reeds.

I used my die filing machine with the table tilted over to 7.5° to bevel the frame edges, filing up to a line engraved by the CNC mill. I deliberately left them a bit on the tight side, then later on after I’d made the reed pans, I hand fitted each frame to its slot with a hand file.

I shortened the clamp screws by first clamping the reed tongue blank in the frame, then grinding the screws almost all the way on a slow grinding wheel, followed by lapping them flat on a piece of fine emery paper glued to a sheet of glass.

All the tongues roughly sheared to size.

Draw filing the edges of the tongues to clean them up, then fitting them precisely to their frame with the aid of my microscope. This is probably the most difficult and painstaking part of the process to get right.

All the tongues initially fitted to their frames; many hours of work have gone into them at this point.

My file was feeling pretty dull so I had a look at it under the microscope. All the teeth had their edges fractured off. No wonder it wasn’t cutting so well any more!

I probably should have bought a new file at this point but I kept going and did much of the profiling with it (I also used a three square file for some of the work). I can’t remember if I’ve written about the fixture in this picture before. It has an adjustable-height step that you place the tongue against. The clamp is a pair of locking pliers that have been modified to have a sharper nose.

The full set of reeds, profiled and rough-tuned. They start out very high initially and go lower as you profile them. I stopped filing when they reached somewhere between +5 and +20 cents sharp on the tuning bench, knowing that they were likely to go a bit flatter once in the instrument. The way they are arranged in this photo shows the unisonoric reed pairs for the left hand on top and the right hand on the bottom, with a few notes of overlap in the middle. If it was an English or Anglo concertina the distribution would look very different.

It’s been said by other makers that, of the many time-consuming stages involved in making an English-style concertina from scratch, the reeds are the greatest. I think I can definitely agree with that statement. I probably spent at least a couple of hours on every reed, maybe more when I include time later spent troubleshooting and fine-tuning.

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Brun Part 5: Bellows

The fifth instalment in the story of building my first concertina is about the bellows. First I had to make a new, rectangular mould to assemble them on. The stock for the forms was constructed from strips of softwood glued across a plywood base, which I then ripped into four pieces.

I again milled the forms to shape on the CNC mill. One thing I did differently this time was to rough them out in staircase form with an ordinary ¼” end mill first before cleaning them up with the large V bit.

When I made the forms for the hexagonal mould, I cut straight into the material with the V bit using lots of shallow passes, which caused lots of noise and vibration, resulting in a poor surface finish. Removing most of the material with an end mill first gave much better results.

The wide forms stretched the machine to the absolute limit of its Y axis capacity.

The bandsaw I had at the time wasn’t capable of ripping the angles off the undersides of the forms, and I don’t own a table saw, so I did them with a hand rip saw instead.

The rectangular core was relatively simple to make compared to the previous hexagonal one.

I split both of the long sides to make the mould easy to remove from the finished bellows.

Cutting the cards by hand with a craft knife. I hate this part; it makes my knife hand ache for days afterwards. Also, because this set of bellows was meant to be relatively heavy-duty for a ‘travel’ instrument, I chose to use thicker 1.5mm card rather than the standard 1mm stuff I used on the tuning bellows (in hindsight this may not have been a good idea because it made the bellows a bit bulkier). I have since bought a special card cutting guillotine that in the future will make this operation much quicker and easier.

Rounding the corners of the cards with a gouge. I started off pressing down onto the bench, but I found it was easier to put a cutting board in the vice and lean against the gouge handle with my hip.

I rounded the tops of the cards on a linisher (bench mounted belt sander) with an 80 grit belt. In hindsight I should have done this outdoors because everything in the garage including my car wound up covered in a thick coating of fine grey dust!

The rounded top of a card. This gives a nice shape to the peaks of the bellows folds, though in hindsight it would have looked better still if I had rounded the pointy corners a bit more.

I decided to try hinging the cards together with a self adhesive linen hinge tape made for bookbinding and other card related crafts. The roll was quite wide so I cut it in half. This picture shows the result of a strength test: the surface of the card ripped off before the glue or the linen failed (and it took quite an excessive amount of force to do so).

I started by hinging the cards together on the inside. The peak hinges can be taped with the cards laying flat, but it’s better to do the valley hinges with each pair of cards in the closed position (or flat but with spacers holding a slight gap between them), otherwise they will later resist closing.

I folded them up and clamped them tightly like this for a couple of days to help the tape glue to really bond well to the cards. Note that the end cards are slightly taller because the end boxes are about ¼” bigger than the bellows. This is partly cosmetic and partly to avoid the bellow peaks touching the table when you put the concertina down.

Next I tied the sets of cards to the mould with plastic coated gardening wire. Elastic bands would probably have been easier but I didn’t have any long enough. Note that the bellows frames aren’t attached to the mould. This wasn’t possible with this instrument because the frames have a divider across them due to the split reed pan design.

I ran the self adhesive linen tape all the way around each peak. This gives a stronger bellows than if you just put small pieces on each corner.

Afterwards I took the full set of cards off the mould and again pressed it tightly for a day or two to help the top hinges stick as well as possible. You can see in this picture what I meant about how it would have looked neater if I had rounded the corners of the cards a bit more.

I needed wider hinge strips on the end cards to attach the bellows to the frames, so I cut those from the ‘Fraynot’ hinge linen from Shepherds bookbinders’ suppliers that I used for all the hinges on my tuning bellows. I cut it on the bias to make it less likely to fray or rip.

Then I glued them on. From this point on, I used hot rabbit-skin glue for everything except the decorative papers.

A brief digression about my experience with the self adhesive hinge linen. In future I’m going to go back to using the Fraynot linen cloth for everything. Although the self adhesive tape worked fine and I don’t think it’s likely to come apart, I found that I much prefer working with the Fraynot and a liquid paste/glue, because if it goes on wonky you can peel it straight off and reposition it, whereas the self adhesive tape sticks instantly and you have to tear the surface of the card to get it off again, then throw away that strip of tape. The tape is surprisingly expensive too, though that’s not my primary consideration. It also had quite a lot of wrinkles in it where the cloth had stuck to itself during manufacturing and the glue is so strong it’s not possible to pull the wrinkle out; sometimes I had to waste a section of it to avoid putting a wrinkled piece on the bellows where it would be visible through the leather. Most importantly, I believe the hinges I get with strips of cloth are noticeably thinner and more supple than with the tape. The difference is fairly subtle when looking at a single hinge, but an entire bellows set with hinges on both sides of the peaks feels relatively stiff and bulky when assembled with the self adhesive tape. Although it’s possible the tape is made from a heavier cloth, I suspect the main difference is in the properties of the glue. I have found that traditional wheat paste doesn’t noticeably stiffen the hinge at all, whereas rabbit glue does stiffen it a little initially but after working it for a while it ‘breaks in’ and becomes supple again. Whatever is on the self-adhesive tape has a rubbery feel to it, and seems to add a bit to the thickness of the hinge too.

I covered the bellows with a nice brown goatskin leather from Hewit, cutting it into strips with an Olfa rotary cutter, which really cuts very nicely, much easier to use than a craft knife.Using my Scharffix 2000 to pare the leather down.

Thanks to a thread on the concertina.net forum, I learned that Israeli-made Personna safety razor blades fit the Scharffix and cut really well, better even than the thicker OEM blades that came with the machine. It’s crucial with this machine to use ultra-sharp blades, otherwise it behaves terribly, stretching and ripping holes in the thin leather.

Checking the thickness of the valley strips.

And gluing them on:

 

Cutting out the gussets with a template and craft knife. This is rather a tedious job; a die tool would make it much quicker.

I use the Sharffix to do as much of the skiving as possible, but the gussets always need a bit of manual cleaning up afterwards with a skiving knife.

Gussets glued on. It proved rather a pain to get the bottom corners to fully stick to the valleys without leaving a little gap. I wound up waiting for them to initially dry, then adding a bit more glue to each gap with a tooth pick and pressing it down with a bone folder until it stayed in position. This is less of a problem with bellows that have more than four sides because you don’t have to stretch the gussets around such a tight angle.

I roughed up the tops of each gusset slightly with sandpaper before gluing the top runs over them.

Cutting more long strips of leather for the top and end runs. It’s a pain when the Scharffix goes wrong in the middle of one of these strips because you need the whole run to be good to avoid having more than one joint.

Top runs glued on.

Next I needed to take the bellows off the mould and attach them to the frames, starting with the hinge linen.

Now the end gussets. This was way more difficult to do neatly without the aid of a mould. It helped to use a stick clamped to the frames to hold them a fixed distance apart.

Finally the end runs. As I mentioned in part three, here’s where I realised I’d made a mistake in not making the bellows frames a tiny bit smaller than the action boxes, in order to hide the edge of the end run. I skived the edge down as close to nothing as I could and tried to get that skived edge flush with the edge of the frame, but it was impossible to get it absolutely perfect, so when I subsequently trimmed the extra off, the edge wasn’t infinitely thin any more so it is possible in places to see a tiny bit of unfinished leather. I recognise I am quite possibly being over-critical of my own work here!

Looking pretty good!

For the decorative papers, I took a sample of the leather down to my local craft shop and looked for a patterned decoupage paper that went well with it. This is what I found. I avoided cutting papers from the area near the bottom that looks dirty (the design is actually printed that way).

I spent a pleasant evening cutting out papers and pasting them on while watching TV programmes in the background.

The finished bellows. I think the papers really go quite well with the leather. Although they were still quite stiff and springy at this stage with a preference for remaining open, I subsequently spent quite a while pressing them and exercising them, and they gradually broke in and became easier to play.

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Brun Part 4: Actions

Part four of the story of how I made my first instrument is about the actions (i.e. the mechanisms that uncover holes and let air through a reed when you press a button).

I made the action boards from birch plywood on the CNC milling machine, which seemed to work pretty well. Although I’m sure high-quality plywood is a good choice for strength and stability, on the next instrument I may try making the action boards from solid wood instead to see if it has a beneficial effect on the tone.

Another thing I will probably do differently next time is to not drill the button peg holes at this stage using CNC. They need to be very accurately aligned with the button holes in the end plates for the buttons to work smoothly, and by doing it this way it took me a lot of fiddling about to get the two boards to line up well enough to avoid the buttons sticking. I think a more accurate way would be to bolt the action boxes together with the action boards inside, then use the pillar drill and spot through the end plate using a drill bit glued into a mandrel that is the same diameter as a button (not my idea: I recently heard about this technique via another maker).

The action boards sit in a rebate in the bottom half of the action boxes. The problems I had with the walls not gluing up perfectly square meant I had to make careful adjustments to the edges of the action boards to get them to fit snugly in the rebates while also accurately aligned with the button holes.

I turned a couple of cylindrical brass dies that mark a circle around each pad hole to help glue the pad in the right place.

Lots of pads.

I made a couple of button guide boards to hold them in the right place while gluing the pads on.

Fitting the cross hole bushes in the buttons (see my earlier article about how I made them) using Bob Tedrow’s method of pulling a strip of cloth through them all, then snipping them apart with scissors:

I cut the lever posts from 1.5mm brass on the CNC mill:

And the levers themselves from 1mm brass:

It took quite a lot of fettling with needle files and emery paper to clean them up. I put the pivot points at the half way points for reasons that made sense on the drawing board, however I have since learned that it is better to put them closer to the button if you can find the space to do so (this causes the pad to lift up by more than the distance the button travels down). In hindsight this may have helped with some of the issues I later had with ciphers because I could have reduced the button height by 0.5mm without compromising the amount of pad opening.


I already wrote about the die I made to thread the grommet ends of the levers, but I have since learned that I get a cleaner, more consistent result from it if I squeeze the tool in a vice instead of hitting it with a hammer.

Before and after forming the threads:

Riveting went fairly smoothly. I only had to redo a couple of them because the pivots tightened up.

The reason for the odd shape of the lever posts is so I could knock them in or pull them back out using a tool with a matching notch cut in it (not my original idea).

The tool has a flaw: because the socket is on an edge of the tool but you hit it in the centre, the force is transmitted to the post off-axis, which tends to cause it to go in at a slight angle. I had to straighten up each post with needle nose pliers after knocking it in. I will probably modify or remake the tool before the next instrument to prevent this happening.

All the levers and buttons installed. Unfortunately I discovered a significant problem at this point. The button ends of the levers were too fat, making them very stiff, especially on the shortest ones.

I didn’t want to pull them all out again, so I instead used a rotary burr and needle files to slim them down in situ, which solved the problem.

Some of the springs.

An action board with all the springs and pads installed. Some of the spring locations proved problematic due to lack of space around the middle row of pads, and I wound up spending quite a bit of time working on getting the button pressure consistent across the instrument while also eliminating ciphers (notes that don’t stop playing when you let go of the button). Most of the ciphers were caused by the end of a lever or part of a spring hitting the underside of the end plate; there was really almost no wasted height inside the boxes.

Adjusting the heights of the buttons to get them consistent is done by bending part of the lever it’s attached to. To make this easier I made a pair of special tools from old screwdrivers to grip the levers in situ.

Overall, I’ve learned that there’s nothing tremendously difficult about building a concertina action, but there are lots of little parts to make and it takes a great deal of patience to assemble and adjust it until it works smoothly, consistently and reliably.

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Brun Part 3: End Boxes

Part 3 of the story of how I built my first instrument is going to cover the main wooden frames of the instrument ends; the bellows frames and the walls of the action boxes. I came up with what seemed like a clever plan on paper, but quite a few things went wrong along the way leading to a lot of fiddly corrective work and a couple of slight cosmetic issues in the finished instrument. The next instrument is definitely going to involve some significant changes in the way I build the end boxes.

I had read that good quality vintage instruments were commonly built from sycamore, typically with decorative veneers like ebony or rosewood on the outside, though for this instrument I decided to go with plain solid sycamore and try to use nicely figured pieces of it for the most visible parts of the walls. I struggled to find a timber supplier that stocked quarter sawn sycamore, though after much searching I found a place thirty miles from me that had a stack of roughly 2 ¾” thick slabs that had been plain sawn and kiln dried. I went and searched through them and picked out one taken from the middle of the tree, so it had two quarter-sawn (ish) sections either side of the pith.

I used my circular saw to cut off a section and remove the pith (the centre of the trunk, where the growth rings become very small). If you click on the next picture to zoom in and look at the growth rings, you should be able to see what I mean. The areas where the rings meet the surface at a right angle are known as quarter sawn, and on sycamore they will show pretty figuring after planing it smooth.

I next used my wimpy hobby-grade 9″ bandsaw to further break the chunks down into a set of thin boards approximately 3″ wide. It just barely succeeded, cutting very slowly with a great deal of groaning and stalling. I have since bought a much more powerful 12″ bandsaw that will make this sort of operation a breeze on future instruments.

I cut more of them than I needed so that I had a selection from which to work around knots and pick the prettiest faces to be visible on the outside of the instrument. After ripping them on the bandsaw I stacked them with air gaps around them and let them acclimatise for a couple of weeks; this proved to be a good idea because they definitely warped a little in the first few days.

After drying I picked out the nicest ones and planed the best face flat, revealing the medullary ray flecks and occasional ripples:

I mitred the ends, using the planed face as my reference:

Then I cleaned up the mitres and trimmed them to exact length using a special 45° shooting board I made for the purpose:

Trial assembly gave me my first real feel for how big this instrument was going to be relative to my hands:

Here’s where my clever plan begins. I had the idea to cut various rebates and steps and sound holes and things, and even the tapered area of the bellows frame using the CNC mill, before gluing the boxes together. This part actually went fairly well, apart from me messing up the first one due to a programming error. The main problem was that it took quite a lot of work to do the CAD and CAM to program the machine (there were actually six different programs due to the differences between the sides: left left, left right, right left, right right, tops, and bottoms). You might also have noticed that I used sycamore for both the action boxes and the bellows frames: I’ve since learned that it is common to use a lighter, cheaper wood for the bellows frames; if I’d done that I could have still used the same technique by gluing a strip of sycamore and a strip of whatever secondary wood together before machining them as if it was a single piece.

Trial assembly of all the sides before gluing:

Gluing. Here’s where things started to go wrong. The sides seemed to warp slightly when I put the glue on, making it extremely difficult to get them to line up perfectly. My first attempt was clearly a mess so I broke them apart before the glue had dried, washed the glue off, and tried again.

Second attempt didn’t look too bad at first:

But on closer examination, most of the joints were slightly squiffy, some more than others. It may not look like a lot, but it caused me all sorts of headaches further down the line.

Unusually, the instrument has two reed pans per side. This meant I had to make a pair of dividing walls for the bellows frames:

Next I cut the boxes apart into their three sections: the bellows frame and the two halves of the action box. I was a little nervous about this step but it went smoothly. Those slots routed in the walls are there specifically to make it easier to cut the boxes apart.

Incidentally, I didn’t know at this stage how deep the reed pans were going to be so I made the bellows frames fairly deep to be on the safe side. They probably could have been 5mm shallower in hindsight. This caused me a bit of a headache later on because I ended up having to accurately shim the bottom of the reed pan recesses on both sides because they were both deeper than the reed pans I actually made.

Next I had to inlay the captive nut plates in the bellows frames, and drill the bolt holes in the action boxes. All sorts of things went wrong during these operations, some of them because the frames weren’t perfectly square, some because my milling machine wasn’t big enough to get to all of the walls without turning the boxes 180 degrees. I’ll definitely be working on coming up with an easier and more reliable way to do this operation for the next instrument. The worst thing that went wrong was one of the bellows frames came loose from the (inadequate) clamps and the router bit tore a chunk out of the inside of the wall.

I had my finger on the emergency stop button and managed to hit it before it had done too much damage:

I repaired it by cutting a section out, gluing in a new piece, and planing it flush:

The repair is hidden on the inside of the instrument, underneath the chamois leather gasket.

With the nuts installed, I was able to bolt the boxes together and lightly plane the outsides to get the walls to match up nicely (zoom in to see the nice figuring):

I slightly rounded all the corners so it feels comfortable to hold:

The outside of the bellows frame needed planing to taper it down slightly and round the corners where it meets the bellows, which are deliberately slightly smaller than the boxes and have rounded corners.

I then lightly French-polished the action boxes, leaving the bellows frames bare because I needed to glue the linen and leather to them. After all the difficulties I had polishing the end plates, I was starting to get the hang of the technique by this point and did a much more satisfactory job of polishing the action box sides. If you zoom in you can see how it really brought out the figure of the wood. The dye in the meths still made the finish look a little bit purple, though!

I made a rookie mistake at this stage: as you can see in the previous photo, the bellows frame walls perfectly meet the action box walls with no step. What I should have done was to plane the action boxes a tiny bit smaller, so that when I glued the leather on, the leather would have been able to come right up to the underside of the action box without the edge being visible. I tried to work around the problem by skiving the leather down to virtually nothing where the frame ends, but it didn’t work perfectly and the join between the two looks slightly crude. It probably also would have helped if I’d made the end run a couple of mm wider and wrapped the skived edge of the leather around the corner a little, so the edge of the leather end run was clamped inside the joint between the boxes, underneath the chamois gasket.

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Brun Part 2: End Plates and Hand Rails

Apologies for the long delay since part 1 of this short series about how I built my first instrument, Holden Concertinas No. 1, a small rectangular 30 button Hayden Duet. I have now finished the instrument and begun design and tooling work on No. 2, which will be a more conventional hexagonal 30 button Anglo.

First a caveat. This was my first instrument, built from scratch without plans or instructions, in some cases involving materials and techniques that were new to me, not under the direct guidance of an expert (though several experienced makers offered useful advice when I had a specific question). I was constantly figuring out how to do things and building tools as I went along, and sometimes my ideas didn’t work out perfectly, or by doing a process one way I learned something that helped me to see a better way to do it. In some cases I was limited by the tools available to me, and I made a point of making everything myself in my own workshop (apart from the stainless steel screws). I think overall the instrument turned out remarkably well, with a few mainly cosmetic flaws, but there is certainly plenty of room for improvement when I build No. 2. This article is the story of how I did it on my first attempt and what I learned along the way, not a definitive guide to building one yourself.

The wooden end plates were made from 3mm birch plywood (the best quality I could find), hammer-veneered using hot hide glue and a veneer hammer I made myself from oak with a brass blade. The top veneer is a very pretty fir burr (or burl for the Americans), with a cheaper beech veneer on the bottom (you always veneer both sides of a board at the same time to reduce warping; in this case it also helped to thicken and strengthen the board). Unfortunately on the finished instrument the beauty of the pattern is rather hidden by all the piercings, buttons and handles, though there are areas where it is still visible. I dried the board between paper in a simple press for a week or so. After taking it out, it warped slightly, but it was flexible enough that screwing the plates to the rigid end boxes pulled them flat again, and in fact I now find that after a few months being held flat by the boxes, they remain flat when I take them off.

I decided to try French polishing the instrument, and I thought it would be easier to polish the board before I cut out the fretwork (in hindsight this was probably a mistake). This was my first time using the technique. It took a very long time, I made a bunch of mistakes, and the results weren’t entirely satisfactory. I learned a great deal, though, and I’m sure the next one will be better. One of the problems I ran into is that in the UK the sort of alcohol you can buy in a DIY shop (methylated spirits) has a small amount of poison and purple dye added to it to prevent people drinking it. It turns out that if you dissolve blonde (clear) shellac in ordinary purple meths, the dye doesn’t evaporate along with the alcohol, it stays in the finish. The thicker the finish, the deeper the purple, and due to inexperience I accidentally made the finish on the end plates way too thick. Funnily enough the change was so gradual I barely noticed it happening, until I happened to place the polished board next to an offcut of the original veneer! For my second instrument I am planning to try dissolving the shellac in clear ethyl alcohol that I found being sold online for medicinal purposes; it’s quite a lot more expensive than meths per litre, but I don’t need huge amounts of it to polish a concertina.

Next I cut the board into two pieces and stuck my cutting templates to them, then drilled all the holes on the CNC mill. Ignore the fact that the mounting holes appear to be in the wrong places – there was a reason I had to do that, which I’ll talk about in the next instalment. The fretwork design is my own, inspired by Indian mandala designs. Circles within circles within a circle within a square. It may not be to everybody’s taste but I am rather proud of it. The space below the fretwork was left empty because I knew the handles needed to go down there, but I didn’t drill any mounting holes at this stage because I hadn’t yet figured out exactly how or where they were going to attach.

I couldn’t drill the button holes to final diameter on the CNC mill because the drill bit I had was too long for the Z height of the machine, so I instead drilled small pilot holes and then manually enlarged them on the pillar drill. I was a bit worried the face veneer would splinter out when the drill bit entered the board, but I used a sharp brad point bit, fed it in gently, and they all turned out perfectly.

The end plates fit into rebates in the end boxes (in order to hide the cut edge of the plywood), which meant I had to do some fiddly manual trimming of the edges using a block plane and shooting board to get them to fit in perfectly without a gap.

I cut the fretwork by hand with a vintage fretsaw. It may look tedious but I actually really enjoy this part of the job!

Here is a little video clip of me working on the piercing while listening to Lady Maisery on the stereo (you have to click it again to stop it playing or it will automatically repeat):

After I’d finished piercing and peeled the sticky paper templates off, I found that the thick shellac finish had gone rough, so I decided to sand it down and try polishing it again. 

The result was a significant improvement, though not totally perfect. In hindsight I probably should have kept going, taken all the shellac off, and completely started from scratch, but I was loath to do that because of the many hours it had taken me to build it up in the first place.

I reamed the button holes out a little from the back using a taper hand reamer, then glued in bushes made from 0.85mm piano bushing cloth. This is a fiddly job that is difficult to do neatly, though I found that I got better and quicker at it with practice. Here’s a quick video clip showing how I did it using hot hide glue. I’m working from the back but aiming to get the front edge of the cloth to sit flush with the front face of the end plate because it’s not possible to neatly trim it flush afterwards.

After the glue had dried, the buttons fit in the bushes but there was too much friction, so I turned a tapered polished brass rod the same size as the buttons and used it in the milling machine spindle at 10,000 RPM to burnish the inside of each bush. This had almost no effect! Second attempt, I made another tapered rod that was slightly larger than the buttons, and waggled it around a bit in each hole. This made the holes just right so the buttons went up and down with hardly any friction or noise. After a couple of weeks I found that a few of the buttons were sticking because the bushing cloth had bounced back, so I repeated the burnishing operation. This second burnishing seems to have done the trick; months later the buttons are still working smoothly.

The extra bit of felt sticking out of the back of each button hole was in some cases interfering with the cross holes in the buttons and preventing them closing fully, so I trimmed them all flush with the back of the plate.

On to the hand rails (I know I’m skipping over the casework and action; I’ll cover those in another instalment). I had an idea to try making more ergonomic handles and spent a while experimenting with a set. Unfortunately they didn’t really work out for various reasons that are outside the scope of this article, but I’ll include a couple of pictures because I think they looked rather pretty.

Back to the drawing board, I decided to make a pair of simple Anglo-style hand rails, but with the ability to adjust them backwards and forwards, and a spacer block that allows the height to be raised or lowered.

The top parts of the rails were made from slightly spalted apple wood from a tree that was taken down in my best friend’s orchard:


The spacers below the main rails were made from contrasting sycamore wood:

While planing the two pieces to match each other, I clamped them together using the same bolts and captive nut plates that would later be used to hold them onto the end plates:

Because the handle could be adjusted back and forth, it didn’t make sense to attach the strap to a fixed point on the side of the action box, which meant I instead had to put the strap clamp screw on the end of the rail. This meant making a captive nut that fit into the end of the rail, and was held very securely by one of the main attachment bolts passing through a cross hole drilled through the nut:

This wasn’t my first attempt at making thumb screws: the earlier ergonomic handles had four larger-diameter screws. I think the final ones I put on the instrument turned out reasonably well, though the knurling isn’t as neat as I’d like due to the knurling tool I bought being a bit too sloppy. I am planning to make a stronger tool with finer wheels before I knurl the screws for the second instrument.

I lightly French-polished the handles and cut the straps from 2mm full grain veg tanned calf skin. I think the shape worked out OK, though I did the decorative creasing around the edge using a tool improvised from an old soldering iron and it went a bit wonky in the curved areas (I’m planning to get or make a better creasing iron before I make the next set of straps).

I found that after playing the instrument for a few minutes the thumb screws started to unscrew themselves. The solution came in a photo I found of a Dipper instrument that had the thumb screws in the same location: a clamp plate like a large washer that is bent around the end of the rail. This prevents the screw turning when the strap moves and looks quite snazzy too! I have since seen exactly the same arrangement on instruments made by Geoffrey Crabb. I put the two bends in the clamp by clamping it in the middle of a toolmakers’ clamp that happened to be the same width as the rail (1/2″).

The final touch on the end plates was to add my maker’s label. The design was hand lettered by my talented friend, Oliver Densham, in a style inspired by the labels used on vintage Victorian instruments. I laser-printed it onto archival grade paper and sprayed it with a special protective lacquer intended for decoupage art, so it should hopefully last a long time.

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