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Dave Higham

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Everything posted by Dave Higham

  1. When I made the bindings I made an extra bit but not as deep as the rest which is glued in place here. This means that when I finally get to cutting the bevel I won’t have to cut right up to the purfling The ends of this piece of binding will need to be pared down to be flush with the purfling before installing the ‘real’ binding. Like so. I actually did this by running the router round the binding ledge again, which nicely tapered off the ends. Now I can install the ‘real’ binding. The height of the binding was reduced to about 2.5mm (0.1”) in the area of the armrest which made it a lot easier to push down to the side profile. I let this piece of binding overlap the tail graft as I need it to be glued to the sides but not to the tail graft (or I won’t be able to get the access panel out). Glued in the treble side top binding too. I then set about cutting the bevel. I took most of it off with a spoke-shave, but didn’t trust myself to get an accurate 45° by hand without accidentally rounding off the corners so I made this rather cumbersome looking sanding thingy. It worked really well, doing most of the work with 80-grit abrasive and finishing off with 150-grit. I finished up with a triangular section groove next to the top and side bindings so I glued two fillets in and sanded them off flush with the rest. You can just see where they are in this photo I realise this is getting very long-winded (and perhaps boring), but the truth is I decided to make it as detailed as possible, mostly for my own benefit. Because I knew that the next time I made one I wouldn’t be able to remember half of how I did it the last time.
  2. I then cut the rebate for the top purfling and finally got a fairly smooth transition into the armrest. Not perfect, but not bad for a first attempt. I stuck this off-cut from the top back where it came from while routing the purfling rebate, so that the ‘donut’ which rides on the top didn’t fall into the armrest area and ruin everything. The top purfling was now glued in place. (Why don’t they make it long enough to go all the way round?)
  3. The last photo gives a false impression of what the armrest should look like as the shape includes the surplus which will be trimmed off after the top is glued on, as shown here. My intention was to try to achieve a smooth blend of the armrest into the body shape. I then re-routed the binding rebate, slightly deeper than the first time. At this point the transition from armrest to body profile still isn’t smooth, but the purfling rebate has still to be cut. I decided, this time around, to make wooden bindings using the off-cuts from the sides. The front bindings can be straight, but the back has such a wavy profile that I used the templates I made for the linings to make profiled back bindings. It wasn’t wasteful as the side off-cut already had that profile. It just needed smoothing out. This time, I glued a single white side purfling veneer to the bindings before bending them. I used waterproof (exterior) PVA wood glue and it worked fine. The two bindings back-to-back (nearest the camera) are the straight ones for the top. The other two are the wavy back bindings which couldn’t be bent back to back but the purflings didn’t come unstuck even so. There was a little spring back, although there doesn’t seem to be in the photo. That’s because the bindings were stuck to the kraft paper and the paper stuck to the slat. You can see the little green clips I spoke about earlier. There are 8 in all and they keep the inner slat in place while dismantling the rest, so the slat can’t straighten out and break the bindings. Now I needed to cut the armrest profile into the side. I drew the curve I wanted and stuck it onto the side and very slowly and carefully cut it using a craft knife and chisels.
  4. What happened next was that I glued the front on, routed for bindings and glued in bindings and purflings and during all that I completely forgot about taking photos. I also have to confess that I chickened out on the arm-rest bevel, so I just installed faux tortoise binding without side purflings. It didn’t look very nice. My little 1/8” down-cut router cutter was knackered so there was rather a lot of chipping out in the binding rebate that I only noticed when I’d finished cutting it. But I was hoping that glue and sanding dust would disguise it. This curly Claro does seem to be rather brittle and chips easily. The cold weather had set in (this was in January) so I‘d bought a humidifier which kept the workshop at about 40 to 45% RH. It worked fine for about a month, and then it gave up the ghost. I took it back to the shop where they said they’d have to send it away to be repaired and then we left for ten days to go to Venice for the Carnival. Of course, I should have turned the heating off in the workshop, but I forgot and when we got back I found the humidity down to about 20% and the top had a 5” crack in it. Oh, and a message from the shop to say that my humidifier was ready for collection. I didn’t mention this before, but I’d already had a couple of problems with the rosette. One was that there was some slight tear-out of the spruce in the purfling channel. The other was that in spite of sealing with shellac, it would appear that some of the CA leached into the end grain of the spruce and discoloured it slightly. I think the problem was that the shellac I used is old and didn’t dry hard, but I decided it would have to do. I now had a distinct feeling that something or someone was trying to tell me something. Like I shouldn’t have ‘made do’ with tear out in the rosette channel, CA staining the spruce, using plastic binding and avoiding the side purflings and chickening out on the arm-rest bevel and was now being told to try ‘making do’ with a cracked top! So with more than a little helpful advice from kind people on another forum, I routed the top off and started again; which is why some of the previous photos are of the first top and rosette and some are of the second. Having decided that this time I should try to make a proper job of it, I made a new top and thought I really ought to have a go at the arm rest. By now, I’d gleaned some more information about how different people go about it and one thing I’d found is that some cut the armrest profile into the top and the side before assembling them. I couldn’t do that with the side as the lining was already glued to it, but I could do it to the new top, so after a bit of fiddling about drawing the profile in CAD, I cut the shape into the top and this is what it looked like.
  5. Thanks for your comments Biz and Gogzs. I truly don't think of myself as a 'craftsman', perhaps because in the past I worked with some real ones (silversmiths). The boss was a reputed designer/silversmith who also taught at the Art College so he only invited the best of the apprentices who studied there to come and work for him. We called him 'Hawkeye' because, if there was the slightest blemish on a piece of work, he saw it! I suppose some of the attention to detail, etc., rubbed off on me.
  6. So now I need to make the bits that hold it in, starting with these two little maple blocks. And this aluminium channel. You can see how it works from the drawing. You slide one end of the channel in, pivot the other end into place and slide it back to centralise it. The little blocks then stop it falling inside the body when you install the panel. The blocks are glued in place. One end of the channel inserted. The other end swings in and the channel is centralised. A small block of wood is glued into the channel to take a wood screw. The panel is now held firmly in place by that big wood screw and can be planed down flush with the sides. The wood screw is temporary; it will be replaced by an end pin after finishing. Now I can glue the back on.
  7. Now I had to make a corresponding hole in the sides. To do this, I made another disc from MDF with a 5mm hole in the centre, and which fitted snugly into the hole in the tail block. This was dowelled to an MDF base. The end block was aligned with the dowel pin and fixed to the base with double sided tape. The hole was then cut using the circle cutter and a ledge carefully cut to fit the circular mahogany panel. The wedge was then fitted into the circular panel and the panel positioned in the hole. A line was scribed on either side of the wedge and a recess cut to accept the ends of the wedge. The wedge is now finally glued into the panel and the panel fitted into the sides. The panel is almost flush with the sides in the centre but, as it is flat, it protrudes more at the outer edges. To trim this down flush with the sides, it will need to be held firmly in place.
  8. The back and front were now ready to glue to the sides but, before doing that I had to make the access panel. The access panel isn’t really essential, but it means I can get my hand inside the guitar to adjust the yaw or pitch or whatever of the neck without taking the strings off. If I knew what I was doing, it would also enable me to get inside to fine tune the brace carving with the guitar strung up; but I don’t, so it won’t. I should also mention that this, again, isn’t my design; I borrowed it, with his permission, from another luthier, Kent Chasson. This is the end graft. The different tiles and strips of veneer were assembled on a piece of 1mm ply and this has now been glued to a piece of maple to make the whole thing 5mm thick. This, together with the birch ply disc we saw earlier and a piece of very old dark mahogany (because that’s what I had), also thicknessed to 5mm, will form the access panel. I trimmed the maple flush with the tiles and glued a piece of white veneer on either side. A 5mm hole was drilled through the end graft to locate it, and the mahogany cut into two pieces and the cut edges trimmed. The mahogany pieces were band-sawn to an oversize circular shape and glued to the plywood disk. The tapered end graft isn’t glued in place yet. It’s positioned with a dowel pin through the hole and into the plywood disc. Now the wedge is removed and the mahogany trimmed to the required diameter. A piece of white veneer is glued to the outside of each mahogany segment. The ends of the wedge are trimmed, the veneers are trimmed flush with the mahogany but the wedge still isn’t glued in place.
  9. As I said earlier, Stephen Sheriff very generously gave me a detailed drawing of his bracing system and very comprehensive notes on his construction process, so I'll quote him. "I carve the center brace to "fly" over the bridge saddle area, to leave an open space for the installation of bridge-plate transducer pickup elements, or pickups such as the L.R. Baggs Lyric". I didn't intend installing a pickup, but Steve's instructions were so detailed that I decided to follow them 'to the letter'.
  10. After that I carved and sanded the X-brace to its finished profile and started on the fan braces. All the front braces are let into the X-brace to form a solid framework. Here is one of the fan braces with its notch in the X. And here it is in place. The sand paper stuck onto the yellow masking tape was used to sand the underside of the fan brace so that it made contact perfectly with the front and the bridge plate, but I forgot to photograph that too. Here the left and right fan braces are being glued in place. They have had the tops profiled and the off-cuts from the tops are used as clamping cauls. Here the centre fan brace is also being glued. Three fan braces glued. All the braces fitted and ‘carved’. I haven’t a clue about carving and tuning braces so I just made them look nice. There’s no upper transverse brace as I think it won’t be necessary. The part of the fingerboard which extends over the body will be supported by a neck extension, so there’ll be a cut out in the top for that. I’ve reinforced that area of the top with a cross-grained spruce patch. I think that, together with the A-braces, should make it strong enough. If the box implodes I’ll be proved wrong.
  11. The front has a 25-foot radius and the front braces get the same treatment as the back braces. All the braces are clamped together to sand them so there’s less risk of wobbling than doing them one at a time. Starting by gluing the X-brace and the cap. Now I need a bridge plate. This will be laminated from a 0.6mm carbon fibre sheet and a piece of padauk about 1.9mm thick. Apparently padauk is a very musical wood and I had a whopping great plank of it. They were glued together using 30-minute epoxy in the radius dish. The MDF caul was also sanded in the dish to a 25-foot radius. The bridge plate was then trimmed to shape and a piece of cross-grained spruce sanded to the same thickness as the bridge plate and trimmed to fill the space between the bridge plate and the X-brace. Here they are being glued in place. The same sanding caul was trimmed down to fit the bridge plate.
  12. It might. If I had a production line, making the same instrument time after time, it might be worth it. But I don't. I make instruments as a passtime. It's a hobby I enjoy and in the past 15 years or so I've only made two identical instruments (a pair of ukuleles) and I found it a PITA having completed an operation on one, having to do it again on the other. I started making bass guitars because I was plonking along on one in a little folk-dance band and thought 'I could make one of these'. So I did, out of the remains of an antique solid mahogany chest of drawers. It was a 5-string neck-through all-mahogany with EMG Jazz Bass pickups Then a 4-string bolt-on, padauk body, maple and walnut neck, Seymour Duncan MM pickup. A semi-solid 5-string similar to a Rick Turner Renaissance in rosewood and spruce. A 'headless' 5-string for which I made everything but the strings and the Glockenklang electronics. Etc., etc. I admit to sometimes thinking how I can make a jig or fixture to do some operation, and then think 'don't be daft, just grab a plane or a chisel and get on with it'! James Olsen, who makes very beautiful and expensive guitars for the likes of James Taylor has a collection of routers, one for every operation that needs one. But he makes guitars in batches and they start at $20,000.
  13. Now to start on the front. I shall ramble on a bit here, so bear with me. When I started drawing up plans I found French luthier Christophe Grellier’s OM plan on his web site and then thought it wouldn’t hurt to ask around about bracing. I’d been thinking about the PRS acoustics that Martin Simpson and Tony McManus were playing at the time. I’d had a brief chat with Martin Simpson at a folk festival in the UK, and he was genuinely enthusiastic about the PRS guitar he was playing.If you’re not familiar with Martin Simpson, there’s loads of stuff on You tube. For example: https://www.youtube.com/watch?v=EAoQGSiVsy4 The PRS acoustic was developed for Paul Reed Smith by an independent luthier called Steve Fischer and has what they call Hybrid X-fan bracing. I’d also come across another luthier, Stephen Sheriff, who uses a similar bracing pattern. So, I thought, there’s no harm in asking, and I wrote to them both, asking if they were prepared to share information on their bracing systems. I wasn’t counting on getting a reply from either one; after all, they are both professional luthiers. I’ve often said that the world-wide community of luthiers, both amateur and professional must be the most generous one there is. Even so, I was a bit gobsmacked by the answers I got from both Steves. In a nutshell, they both said ‘yes, I’ll tell you anything you want to know’. So, I finished up with a long email from Steve Fisher, explaining his bracing pattern and giving dimensions, etc. and an even longer one from Steve Sheriff with masses of information. He also sent me a full-size, fully dimensioned hand drawn plan of the guitar he makes which is the nearest to an OM and other goodies like radius templates and CF sheet which he uses for bridge plates. So there I was with an embarrassment of riches. I decided to start with the Stephen Sheriff version. By the way, he goes under the name of Edwinson Lutherie. As I said, I’ve used the ‘tent’ method when joining fronts and backs but I’ve sometimes had trouble getting both halves aligned, as, especially if both halves are not dead flat or aren’t the same thickness, when I push the two halves down, the glue grabs and that’s it. So this time I did it in the go-bar deck. The go-bars hold both halves down flat and the wedges force the two halves together. There’s a strip of polythene film under the join area which stops them sticking to the base and helps them slide together when pushed by the wedges. It seemed to work OK.
  14. No, no stopper pins. It would get a bit complicated as they would have to stop at a curved surface which isn't always the same. I just route up to the sides and it doesn't really matter if I cut into them a bit. I cut the braces a little bit short, to leave a gap between their ends and the sides. Braces have been known to expand in length (under extreme conditions) and push the bindings away from the top or back.
  15. I then moved on to bracing the back. Here are all the back braces clamped together to sand the 15-foot radius in the radius dish. Starting to sand. Pencil lines on the surface to be sanded will show when it’s finished. And there are no pencil lines left. Started by gluing the X-brace in place. Then forgot to take photos until I’d glued and shaped all the other back braces. I marked the positions of the back braces on the linings and cut recesses for them where necessary. The Dremel router base is mounted on a board long enough to span the whole of the body. This keeps it rock-steady whilst routing small notches in a narrow surface.
  16. After giving the area of the soundhole a couple of coats of shellac I then cut the recess in the sound board for the rosette and managed to do it without any tearout. I glued the circle in with fish glue and, when that was dry, next day, cut a groove round the inside and outside for the purfling veneers After giving the grooves another coat of shellac I glued the purfling strips in with CA. They were quite tight so just a few drops of CA were all it needed to glue them in. I glued the purfling strips together before gluing them into the channel. I find it easier than wangling several separate strips in at the same time. I took some of the surplus off with a block plane and then sanded the rest flush with the top.
  17. Who (or what) is magic_wood? I googled but didn't find much.
  18. Time to start on the back and front plates. I don’t find joining the plates easy. I’ve tried everything except routing a slot between the two halves (which should be foolproof but I’d need to make yet another jig). The best join I ever got was by simply running them over a jointer, but my planer/thicknesser blades were knackered when I did this. I eventually got them good enough by a combination of improvised shooting board and sanding board. I joined them in the same way as the front, but of course it didn’t occur to me to take photos . . . So, having joined the front and back and cleaned up the front I started on the rosette. Random mosaics were in vogue when I did this and I rather like them, (well, some of them) so I dug out my box of bits and sanded some of them to about 2mm thick. I stuck them down onto a piece of 1mm ply.(The stuff they use to make model aircraft) This overlay showed me what the finished circle should look like. Er… you may have noticed it’s not the same rosette. I’ll explain later. Trimming to finished size. Trimmed.
  19. I suppose I go to ridiculous lengths to make it look that way (or to hide the mistakes)
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