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Category Archives: guitar making

Spalted beech rosette continued

This is the second half of the story, started in my last post, about making a rosette from spalted beech.

The next step was to cut the channels around the edge of the rosette to receive the border strips. Again, I used my jig mounted Dremel for this.

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Here the channels have been cut and the decorative strips bent more or less to the right curvature on the bending iron ready for glueing in.

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And here is the finished rosette, planed flush with the soundboard and given a wipe of shellac. I shan’t cut the soundhole until I’ve planed the soundboard down to it final thickness.

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Spalted beech rosette

A few weeks ago, I bought a block of spalted beech from Mark Bennett and mentioned, in a previous post, that I hoped it would make some striking guitar rosettes. I’ve been trying out some ideas. Here’s the piece of wood that provided the starting point.

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Having decided which face looked most attractive, I set up the bandsaw for a fine cut and sawed two veneers at about 4mm thickness. Then I book-matched them to create a more or less symmetrical pattern, by gluing them onto thin (1/64 inch) plywood for stability. Actually, there’s a bit more to it than that. First, using weak hot hide glue, I stuck a sheet of paper to a 6 by 6 inch square of 6mm MDF. Then I stuck a similar sized square of 1/64 inch thick plywood over that, again using thin hide glue, and weighted it down until the glue was dry. This provided the base onto which the veneers were glued.

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Using a Dremel mounted in a jig (details of jig available here) I cut out the rosette making the depth of cut just through the layer of thin plywood. It was then possible to remove the rosette using a thin blade – an ordinary knife from the dinner table works well – sliding it between the plywood and MDF layers in the plane of cleavage provided by the paper. Any paper or glue remaining on the underside of the rosette can easily be cleaned off with a hot damp cloth, which of course was the reason for using hide glue in the first place.

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I missed the opportunity to photograph either the detached rosette or the routed channel in the soundboard but below you can see the rosette being glued into position on the soundboard, weighted down so that it dries flat.

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More on the V-joint

Looking around for more on V-joints, I found Gary Demos’ site where he describes not only the construction of the joint but how he made a copy of a Panormo guitar. It’s a fine looking instrument and there are a few mp3 files that show that it sounds very good as well.

Cumpiano’s website has a brief discussion of the merits of the V-joint versus the scarf joint too. (You’ll need to scroll down a bit to find it.) I enjoyed his comment:

If you use a v-joint people will shower you with praises for your skill and those in the know will guess that you don’t have to make a living at making guitars.

There’s probably some truth in that. I’ve always admired Cumpiano’s down to earth approach to guitar making and his refusal to subscribe to anything that can’t be properly explained. See, for example, his courteous but uncompromising dismissal of the mystique of tap tone tuning.

Still, in the interests of historical accuracy, I’m going to pursue the V-joint a bit further. It seemed worth shaping the neck and headstock of my trial joint to get an idea of what it would look like on a finished instrument. In reality, it doesn’t look quite as good as the photographs suggest. At this resolution, glue lines, which in places are wider than they should be, don’t show up. But I’ve discovered two useful things: first, that the joint isn’t impossibly difficult to make and second, that it’s certainly strong enough.

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V-joints for guitar headstock

Following on from my recent experiment with a small guitar, I’ve been thinking about going a stage further and making a copy of a 19th century guitar of the sort for which Panormo is famous. There’s one in the Edinburgh University collection of historic musical instruments and, rather helpfully, there’s a measured drawing available. The collection’s website has fierce warnings about all the content being copyright so I haven’t posted a photograph, but you can see the instrument by clicking here.

The neck of this guitar joins the head in a traditional V-joint. This isn’t a technique that I’ve ever used before so I’ve been trying it out, partly to get my hand in for making it and partly to reassure myself that the joint is stronger than it looks. There’s a good illustrated article on making V-joints on the Official Luthiers Forum, although you may have to register with the forum to get access. The geometry of the joint isn’t really very complicated but, on the other hand, it isn’t entirely straightforward either. The article explains it well.

The photograph below shows my rough first attempt being glued up. Hot hide glue is the correct stuff to use but, for this trial run, I substituted Titebond.

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Here it is with the clamps off.

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And after cleaning it up.

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And trying to break it.

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I wondered, in view of the endgrain gluing surfaces of the joint, whether the joint would be strong enough. So I played around, first by loading it with a 20kg weight and then by putting it in the vice and pulling on it as hard as I could. I couldn’t shift it and now feel entirely confident that it’s up to the job.

West Dean

Classic Hand Tools held a show at West Dean last weekend. It wasn’t a big event but I’m glad that I went for all sorts of reasons. One was the opportunity to meet Karl Holtey and to see and handle some of the planes that he makes. Another was to talk to Mark Bennett who, as always, had brought some amazing wood with him. With some difficulty, I succeeded in persuading him to part with this remarkable specimen of spalted beech.

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It’s not a big block (only about 5 inches by 5 inches by 6 inches) but the figure is exactly the right scale for instrument making. My first thought was  that it would make striking rosettes for guitars and I’ve been playing around with designs (using photocopies so as not to waste any of the material). Here’s one idea:

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Walnut guitar with cedar top

A few weeks ago, I mentioned that I had started making a classical guitar with slightly smaller dimensions than usual. I hadn’t got anything radical or particularly innovative in mind but I hoped that, by reducing the diameter of the lower bout, decreasing the depth of the ribs and using a scale length of 640mm, the instrument would be easier and more comfortable for a smaller person to play. The fingerboard and string spacing were also to be narrower by a few millimeters to suit someone with small hands, and the guitar was to be as light as reasonably possible.

The instrument is now finished. The top is cedar with lattice bracing. The ribs and back are of English walnut with an unusual ‘watermark’ figure and the rosette and headstock were made using spalted beech that Mark Bennett, who runs a funiture making business called the Woodlark, sold me a while ago. The fingerboard and bridge are of Rio rosewood and the tuning machines were made by Keith Robson. The final weight, with strings and tuning machines in place, was just over 1400 grammes, which is significantly lighter than the weight of most of my instruments.

It has only been strung up for a day or two and it has yet to be played by a proper guitarist but my first impressions of the sound are good and the volume doesn’t seem to be perceptibly less than that of larger instruments. I’ll try to add a recording sometime but, in the meantime, here are a few photographs of the completed guitar.

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Why don’t girls play guitars?

A report from the UK last year complained that gender stereotyping influenced children’s choices about which musical instruments they took up. Girls get to play harps and flutes, while boys prefer trumpets and drums. I don’t know whether this is really right or that, even if it were, it would be a very terrible thing, but it certainly is true that more boys than girls play guitars. And while this might be gender politics, I can’t help wondering if the dimensions of the guitar have something to do with it too. The body of a concert guitar can be too big for many women to hold comfortably and I suspect that the usual measurements for the string spacing and fingerboard size are optimised for a male rather than a female hand.

I thought that it might be interesting to make a guitar with a slightly smaller body size than usual and combine it with a shorter scale length and narrower fingerboard. The idea is to make an instrument that a woman will find easy and responsive to play without compromising either the quality or the volume of the sound it produces.

The water-mark figure in this walnut is attractive but delicate and I think that it might work well for the back of a smaller guitar:

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The front will be cedar and I’ve inlaid a rosette of spalted beech. I’ve carried the same theme through to the headstock veneer.

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How does it sound?

So far in this blog, I’ve been writing about how instruments are made and showing photographs of what they look like. But what matters most, certainly to players and listeners but to makers too, is what they sound like. The trouble is that it’s not easy to make recordings that do justice either to player or instrument. Having made that excuse, I’m going to try. So here, as a first step, are three short pieces played by Fiona Harrison on this cedar top guitar that I’ve written about before. Click on the labels to hear them.

Piece 1

Piece 2

Piece 3

Experiments with shellac

Unfortunately, the shellac experiments failed to reproduce the problem that I had with the polish that failed to harden. I put blobs of shellac from each of the containers of the stuff that I had in the workshop onto a sheet of glass and left them overnight: all hardened satisfactorily. So I can rule out the possibility that the shellac I was using was too old.

I also French polished a piece of scrap mahogany, using a lot of mineral oil on the rubber and building up a thickish layer as quickly as I could. That worked fine. So Bob Flexner was quite right when he said that it wasn’t the oil causing the problem.

I’m left without an explanation but I have learnt something. First, it’s always worthwhile to check that the shellac hardens using the ‘blob on glass’ technique before starting to polish an instrument. Second, mineral oil is an effective lubricant for the rubber and doesn’t compromise the quality of the finish. And third that, if the polish doesn’t harden fairly quickly, the best thing to do is wipe it off and start again rather than waiting around in the hope that it will harden eventually.

Wrong diagnosis of the problem with the French polish

It looks as if  I’m wrong about the problem with non-hardening shellac that I mentioned in my last post. There, I suggested that it might have been due to using mineral oil to stop the pad sticking when applying the shellac. Bob Flexner emailed me saying that neither he nor the hundreds of people that he has taught have ever encountered any trouble with mineral oil. Indeed, the reason that he prefers mineral oil to linseed oil is that unless one is careful in removing all the linseed oil, it cures soft and gummy on the surface.

I’d like to get to the bottom of the matter, not least because I don’t want to run into the same trouble in future. So I’ve carried out some experiments to try to reproduce the problem using various types of shellac in combination with various types of oil to see if they harden differently. If anything useful comes of them, I’ll write about it.

French polishing two guitars

A few weeks ago, I started French polishing a cedar-topped guitar and, to avoid the temptation of rushing to get it finished, I began making another to give myself something to do while waiting for the polish to dry and harden. Absurdly, the strategy worked too well; I became so absorbed in making the second instrument that I didn’t pay enough attention to the one I was supposed to be polishing. This meant that I didn’t notice a problem: the shellac that I was putting on wasn’t hardening properly.

It took me a while both to identify the problem and to come up with a diagnosis. I’d been using light mineral oil on the pad (instead of the usual linseed oil) to stop any sticking as the polish was rubbed on and I reckon that some of this oil had got incorporated into the finish and slowed up the hardening. The advice to use mineral oil comes from the chapter on shellac in Bob Flexner’s book Understanding Wood Finishing, which is otherwise a mine of good sense. It’s possible of course, that I’m wrong in laying the blame at his door but when I eventually bit the bullet, wiped off the non-hardening shellac and started all over again using linseed oil, the problem didn’t recur. I’d be most interested to know if anyone else has had the same experience. Sometime I must make some experiments with different oils to find out whether this is the correct explanation.

All of this inevitably slowed down completion of both instruments and there hasn’t been much to photograph or write about, which is why there haven’t been any posts for the last couple of weeks. Anyway, I’m now at the final stages. Here’s the current state of the two guitars:

Bridge

The bridge is made out of Macassar ebony inlaid, on the tie-block, with a flash of laburnum to echo the rosette. Earlier today, I positioned it on the soundboard and glued it into place. The clamps are now off but I’m going to be patient and wait until tomorrow before stringing up the instrument. It’s always wise to let the glue cure completely before putting a lot of tension on the bridge.

Fingerboard, frets and neck shaping

The fingerboard has now been fitted and fretted to a scale length of 650mm. I’ve more or less finalized the shape of the neck too. Time to make the bridge.

Binding in place

The binding and purfling went in quite neatly. It’s a simple scheme but I think it will look fine on the finished instrument. You can judge for yourself from the pictures. The apparent staining of the wood in some places is where I have brushed on some shellac to stop the white maple picking up dirt or, worse, turning an orange colour from contact with the cocobolo. It will disappear when the next coat of shellac goes on.

The next tasks are to prepare a fingerboard and make a bridge.

Preparing the binding

The binding is made from sawn veneers of ebony and maple. The photograph below shows a true edge being planed using a shooting board before using the bandsaw to slice off a narrow strip.

Here, a border of maple is being glued to the ebony in a shop-made clamping device.

Below is a strip of the finished binding, bent and ready to be glued into the ledge already routed on the guitar.