banjojohn Posted November 9, 2015 Share Posted November 9, 2015 I have just managed to make an F# reed for my 1895 Lachenal English concertina. My concertina repair manual says 'that on no account should you even touch the reed clamp screws'... and that 'reed making is a highly specialized task, which can only be undertaken by a few practitioners worldwide... ' I seriously didn't think that I would be capable of pulling this one off! It just goes to show that you won't achieve anything unless you give it a go! After approximately 3 hours of very fiddly filing I managed to produce this reed and have it tuned pitch perfect to its partner. When put back into the box it sounded absolutely fine, exactly the pitch, tone and volume as the original reed. I used some vintage brass, which I cut from part of a circa 1935 Alladin oil lamp. This was a pressing from 0.5mm brass sheet, initially I cut a strip about 5mm wide and 40mm long. This was then work hardened by gently beating on an anvil with a small hammer. I then started filing it to the correct shape to fit the slot in the reed shoe. The trickiest part of this was figuring out how to hold such a tiny piece of metal in order to accurately file its edges.. . I devised a method of clamping between two small smooth flat files. I taped the reed to the face of one of the files, precisely positioned, so that only the amount I wished to remove protruded over the edge of the file. I then sandwiched it with the other file and clamped it up with a couple of 2" G clamps. Then using a flat Swiss file I used a draw filing action to file the reed edge down to the edges of my clamping files. I repeated this exercise several times, checking the reed for size each time by using the reed shoe as a gauge. The manual says that the side clearances should be 1.5 thousandths of an inch , so I used a 3 thou feeler gauge in one side of the slot to get the width of my reed correct. Once happy that the size and fit were spot on I clamped the reed up into the shoe. Because my reed was about 40mm long but the required length is only about 20mm, I had an excess 'tail' behind the clamp, having this extra length is important as it makes for easier handling during filing and helps a lot during the final positioning of the reed relative to the slot. I found that holding the reed/shoe up to brightish light, so that the light shines through the side gaps, is a very good way to visually check clearance and positioning. I also used a 1.5 thou feeler gauge to check this. At this stage I had a reed which fitted my reed shoe, but was still about 0.5mm thick over its length, so I needed to file it down to reduce this thickness. I noticed that the broken reed which I was replacing was 0.5mm thick at the clamp end, but had been filed down to about 0.3mm at its root and became even thinner at the tip. I marked my reed at the edge of the clamp and then removed it from the shoe. I then clamped it to a flat steel plate for support, while I filed it to reduce its thickness, again I used a flat Swiss file to do this. Finally I removed all the burrs from the reed edges and smoothed the underside with worn out 400 grit wet and dry paper, before polishing with brasso. I then refitted the reed to the shoe and rechecked the clearances. I put it to my lips and drew air through it and was pretty surprised to hear it sound!!! It was actually very close to being F#, but lacked the brightness and volume of its partner... I figured that this must be because there was still too much mass in the reed, which was affecting the quality of the sound. So out it came again and I filed more off thickness... My judgment as to the right amount to remove was based purely on close visual inspection and comparison with the other original reed. I don't have a micrometer, but then I couldn't have used one to measure the original reed without removing it from its shoe and I didn't want to do that... When it looked right, when viewed against a bright light I replaced it back in the shoe. I sounded it again, this time it sounded brighter and louder than before, only now it was very flat. I was pretty pleased at this stage, all I had to do now was to get the tuner out and bring it up to pitch. The tuner clocked it as being a flat F. I made a little 'file' by gluing a strip of 400 wet and dry paper to the edge of 6" length of 5mm X 20mm hardwood. Then with a 6 thou feeler gauge inserted under the reed, to support it on the shoe, I gently removed material from the reed, from about half way down its length to the tip. After 6 or 7 stokes of the file I checked the pitch, it had sharpened but was still flat of F, so more filing. This process was repeated in the usual way for reed tuning, until finally it was up to the required F#. The last few file stokes actually took it 5 cents sharp, but when I sounded the partner, it was also 5 cent sharp! Result, result!!!... But the best thing, was that it sounded the same tone and volume as the partner. All that remained to be done was to remove the excess tail, simply done by sawing off with a 'junior' hack saw... Both reeds are now back in the concertina and it is playing and sounding absolutely fine! 3 Quote Link to comment Share on other sites More sharing options...
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