Friday, December 29, 2006

Head Joint

The neck and head are now made. The photo above shows the scarf joint; the head is cut from the neck blank at an angle, flipped over and glued back on, giving the correct angle for the head.

It is essential that the head is made this way (or a variation of this method) and that the profile of the neck and head is not cut from a single piece of wood, this results in short grain running through the head and any impact is liable to snap the head off. When I was at College in the 1970’s, I use to do all the repair work for “The Spanish Guitar Shop” in London’s Fulham Road. The most common repair was a broken head, always on cheap Spanish guitars, constructed in this way.

You can also see in the photo a strip of rosewood running down the neck. I always laminate my necks, I feel that the result is a much more stable neck and the stripe effect looks nice! Even if I don’t use a stripe, I will often cut the wood to relieve any stresses, plane it flat and glue it back together. The small holes that you can see in the photo are for wooden pins, these allow the head veneer to be held perfectly in alignment with the neck whilst it’s being glued on.
I’m surprised how many luthiers are using v-joints on their classicals’ necks. The reason for using a v-joint on early guitars was to keep the joint in compression and not stress the glue; however modern glues are much stronger and more reliable and this joint is unnecessary from a structural point of view.

It does however, look good and shows off the luthier’s skill. What concerns me (and this is the reason that I don’t use it) is that there is a fair amount of end grain, being stuck to end grain and that is not good. Woodworkers always avoid this as the glue is absorbed up the wood’s pores, as sap would be, and therefore, it doesn’t do its job. Torres used the scarf joint on his guitars and if it’s good enough for him…….
You can see below the finished head.

When making a guitar you don’t just work on one element at a time so, the soundboard and back are being braced at the same time too.
The wood for the fan bracing is spilt from a billet to ensure that the grain is dead straight and running the length of the brace. I’m not going to say too much about the soundboard; I like to have some secrets!

Monday, December 04, 2006

Cedar Classical

This classical guitar has a Western Red Cedar soundboard which I’ve had in stock for well over 25 years! It has an incredible bell like tap tone. The rosette is complete and I’m pleased with the way the green line complements the colour of the cedar.
The head veneer is made up from the off-cuts of the back, so there is no need to worry about whether or not it matches and I’ve carried on the “green” motif with a strip down its centre, as Hauser used to. The purflings around the top edge will also match: attention to detail is what counts!
The back has its decorative strip in place. I use 0.6 mm boxwood veneer for these lines and the back and side purflings. Boxwood has a very dense grain, its main use, used to be for wooden printing blocks, I guess the close grain means that when you print, you don’t get the texture of the grain showing. That’s a similar reason for me using it, when you sand and finish the rosewood, its purple dust and resin, doesn’t discolour the boxwood, so you get really clean lines.

You can see the rosette, back and head veneer in the picture below.

I’ve just bought myself a new plane, a Veritas low angle bevel up smoothing plane. It works so well on the type of wood that I use.
The low angle bevel up blade does not tear up the grain so you can use the plane for longer before going onto a cabinet scraper. When you are taking the wood down to 2 mm thickness, you can’t afford to tear out the grain so I used to stop using the plane at around 2.5 mm and then scrape. This new plane lets me go down to 2.2 mm before using a scraper. "Big deal 0.3 mm!", I hear you say! Trust me it hurts! The question is why didn’t I buy one of these beauties years ago?
Plane or Scrape?

The guitar’s sides are bent, I use a hot iron (it’s actually aluminium). I love the idea of getting solid wood and bending it by hand to get the shape; the smell of the resins and the steam rising and the guitar’s shape appearing is almost magical.
Looking at the photo, I realised that I’ve got my “Gibson” shirt on. This was given to me when I visited the Gibson factory in Bozeman, Montana last year. This is where they make all of their acoustic instruments; I was amazed to see how much work was actually done by hand.
After the sides, the end blocks are glued in place. I use a mahogany block for where the neck joins. I make the neck separately and use a dovetail to join the two component parts. I feel that I can work with greater accuracy this way. Although this is not regarded as the Spanish method of building, Ignacio Fleta, probably one of the greatest Spanish luthiers, used this method.