Steel string guitars have a true mahogany (swietonia) neck, classical guitars have ‘cedar’ (cedrela) which is a little lighter - both in weight and colour.
For steel strings, various spruces (picea) are good for the soundboard - Sitka, Engelmann, Alpine. Also ‘western red cedar’ (thuya). For classical guitars I use Alpine spruce, but also do a ‘double top’ - spruce with a layer of cedar underneath – see below for discussion. The top is universally agreed to be the crucial factor in the sound. The prettiest, perfectly quarter-sawn, even-grained wood does not necessarily make the best guitars.
Anything goes for backs and sides. Really. Torres made his famous papier-mache guitar all those years ago to prove the point. But you want it to look nice, and decent straight-grained wood is easier to work and bend. Back in Torres’ day, he used locally sourced cypress for his cheap guitars and rosewood, or figured maple, for the posh ones. Flamenco players couldn’t afford the expensive guitars, so cypress-backed guitars evolved into the ‘true’ flamenco guitar. People now debate whether the ‘flamenco negra’ guitars with the rosewood back sound as good as the ‘flamenco bianca’ with the cypress back.
For environmental legislation reasons (CITES), you can’t buy or sell Brazilian rosewood for which many considered there was no substitute. It’s getting harder to get Indian rosewood for the same reason, but I still use it on classical guitars. It is of course very beautiful.
Otherwise, I use cherry, walnut, apple, maple/sycamore/London plane, wenge, ovangkol. These vary enormously in appearance - often very pretty, especially with some ‘flame’. No doubt they have different tonal qualities mostly dependent on density, but it’s hard to predict results in practice because the thickness and the bracing also affect the sound. Wenge, a very dense tropical hardwood, is not in short supply, and has a metallic ring reputedly like Brazilian rosewood. I like it.
Fretboards - ebony. Steel-string fretboards have an ebony binding, which doesn’t show, but eliminates the problem of sharp fret ends projecting in dry conditions. I also put a slight twist in fretboards so that there’s less difference in saddle height between top and bottom strings.
Bridges - ebony for steel strings, rosewood for classicals.
Bindings, purflings, rosettes - I make my own from various naturally coloured woods and from stained veneers where I can’t get a natural colour – eg green!
Steel-string guitars have a two-way truss rod, adjustable at the head end. The pocket is concealed with a cover held by tiny magnets. Classicals have a strip of graphite for neck reinforcement.
I join the neck to the head with a simple splice or ‘scarf’ joint. It’s very easy, very strong and is the least wasteful of wood.
I use a tapered dovetail joint to join the neck and body. This is traditional for steel string guitars, though more and more makers take a bolt-on approach. It’s tricky getting the geometry right, but very satisfying. It’s not normal however for classical guitars. The Spanish method is to build upside-down on a board or ‘solera’, integrating the neck at the beginning. This means my Torres copies are not ‘authentic’. But the great Ignacio Fleta used a dovetail joint, and anything good enough for Julian Bream is good enough for me.
‘Flat topped’ guitars are not actually flat-topped, they normally have some doming. My doming is a bit more than most (I use a 20’ radius), which makes a more stable structure which can therefore be built lighter. My backs have a 15’ or 12’ radius.
I use fairly conventional X bracing on the steel string guitars, usually with a symmetrical arrangement for the lower bars, and the classical guitars have normal Torres style fan bracing.
I have experimented with bridge designs on my steel string guitars. Early ones had a high bridge – the strings went through it to a tailpiece. This combined with a raised fingerboard and worked very well. I now make a bridge where the strings simply slot in to channels. No pins, no need for a reinforcing plate under the soundboard, no feeding strings through holes. It works. I don’t know if anyone else is doing this, so it could be called the Branwell Bridge.
I control the humidity in my workshop – between 40% and 50% is ok.
Guitar making is a combination of empirical and theoretical. But it’s mostly empirical! With musical instruments, theory has come after practice. We can be sure that CF Martin and Torres knew nothing of Young’s Modulus or the Cube Rule when working out how stiff versus flexible to make their tops. They wouldn’t have talked about nodes and modes or Chladni plates either. Certain things can be derived mathematically, and the more precise the better - for instance fret spacing.
But when it comes to working with wood, there are so many interdependent variables, with each piece of wood - soundboard, bracing material - different from the next, even when taken from adjacent pieces from the same tree, that we have to rely on less precise approaches, even something as mysterious as intuition. Factory-made guitars tend to be over-engineered because the process doesn’t allow each plate or strut to be individually thinned or shaped. Does this mean hand-made guitars are generally better? My answer is probably, if the maker is really on the ball and is able to make something that is strong, stable and flexible at the same time. I’ve played some shockingly dull but eye-wateringly expensive guitars, and some cheap laminated guitars that sound heavenly.
Which brings me on to laminates, also known as plywood. My cheapYamaha FG180 from 1969 was made of plywood. A marvellous guitar, it knocked the spots off my band-mate’s old Martin. I played it throughout my time as a working (well, often resting) musician. It even featured in a solo on someone’s top 10 hit! There’s now a posh version of the laminate - the ‘double-top’. It’s generally two thin veneers of wood with a plastic honeycombe material - Nomex - in between. When done well it sounds great. And now we have the ‘all wood double-top’ - truly a plywood. My version is borrowed from George Lowden and involves a spruce top glued over a cedar top with the grain at a slight angle. This is then thinned down to a normal thickness, or a little less. The difference in sound is subtle – a little more volume, a little more attack in the trebles.
Generally though, I follow in the footsteps of the great makers of the past - and the present. There are some wonderful makers, and the fact that some of them talk science and some of them don’t, doesn’t seem to be a factor.
Decoration - My first guitars were super plain - bindings to cover the joins between sides and top and back and a couple of circles round the soundhole, nothing else. I’ve allowed a little more decoration in, particularly the rosettes on my Torres models, but generally I like to keep it simple. The only inlay work I do is my (optional) headstock logo - either a stylised arrangement of my initials, NHB, or a triangular design, plus (optional) pearl dots on fingerboard and on classical bridges. Torres started out with very blingy guitars and got plainer as he got older. Probably shaky hands and bad eyes came into it, but also maybe the need to make affordable guitars.
Which brings me back to my ‘mission’, if you like: to make high quality, resonant, responsive guitars at a price that players can afford.
Each guitar is more or less a month’s work.