How do you get that shape?

Whenever I get a visitor to the workshop, they’re always intrigued by how the sides are shaped. Well here’s the answer! For this instalment of the “Parlour Guitar: design & construction” videos, I thought that I’d show you how the sides are bent. The video’s a bit long, but I didn’t want to leave out any important information for all of you budding luthiers!

Antiques Road Show?

Well not quite! I was delighted to get some photos from Dave of an early Nava! I made this classical guitar in 1979 and remember it well. It was originally sold via the London Guitar Gallery for £200 in 1979 and Dave bought it second hand from the Camden Lock Music Shop in 1983 and has been playing it ever since! The guitar was built during my last year at the London College of Furniture and was the 13^th that I made. The back and sides are made from Brazilian Tulipwood; I remember going to a wood yard to buy some mahogany boards for necks and saw this discarded, tatty, spilt board.

I had a small plane with me so I took a few shavings off the surface and claimed it!! I could only get narrow pieces out of the board; hence this guitar has a three-piece back. Oh how I wish I had some more of this beautiful wood! The rosette is also interesting, it was one of three that I made to this design.

All of the mosaic rosettes that we made at LCF were made from 1mm squares cut from pre-made strips. I felt that this didn’t give a fine enough pattern so I made some smaller mosaics by producing my own 0.6mm squares from veneers. Two of them were used in guitars (this one and its Indian rosewood sister) and here’s the third; in my workshop still unused. To be honest, this one’s a bit scruffy and was the prototype!

The shape of the guitar is similar to the one that I use on my classical today. At this time I was doing all the repair work for a Spanish guitar shop in the Fulham Road and I had to re-finish the back of a stunning Brazilian rosewood Manuel Contreras flamenco. At the time it was one the nicest guitars that I had ever handled and so I based my shape on it.

Richard’s Mandolin

Just in case you’re wondering if I ever glued that neck on! Here you see how the neck fits; it may look like a small joint, but there is over 21 square cm of surface area to glue so it’s strong enough!

Fast forward..............What I do like about making instruments with floating bridges and tailpieces is that you can get them set-up and playing before finishing. So now I have Richard’s mando playing it can be striped back down and be French polished.

Those eagle-eyed followers will note that my bridge design has changed- I’m using a separate saddle this time. Two reason, firstly less wood is used hence it’s lighter but more importantly it offers a relatively easy way to adjust the action. The saddle can be taken out and reduced in height or shims can be put underneath it, to raise the action. I’ve made up two saddles one bone the other ebony and once the mando has been played-in, Richard will be able to give me feedback about the tonal differences (cheers Richard!).

El Corazon’s neck

I thought that I would go through the process of fitting the neck with you. With the body completed, the next step is to route a dovetail slot for the neck to go into. At this stage of construction things start getting a wee bit tense because of all of the time and effort already invested- you just can’t go wrong!

I firmly clamp the guitar body to my jig which gives the tapered shape of the slot. Then using a template follower and straight 6mm cutter the bulk of the wood is cut away.

With the majority of the wood removed, I re-cut the slot with a dovetail shaped cutter. Because of the tapered sides of the dovetail cutter, you have cut to the full depth in one hit which could overload things; hence using a 6mm one first.

Once the slot is cut, I take careful measurements and cut, chisel and file the male part of the joint in the neck. The whole process of fitting the neck joint into the body can take many hours. The neck has to be perfectly aligned in two planes and the heel fit neatly against the sides. I know that some makers cut the neck too small and rely on shims to pack it out but I prefer the best fit I can get. By the way the Jiffy bag is to protect the head from getting damaged!

I have often debated whether or not to use the Spanish method of an integral neck; sound-wise I don’t think that there is any difference and both ways are far superior to using mechanical fixings. However, I am tempted, just for the hell of it, to have a go and I’m thinking of trying it out on the parlour guitar.......we’ll see!

I’ve never been a great fan of classical music apart from guitar and lute music. I guess classical music is a bit like custard; you’re put off by your experiences at school! Anyway, as Radio 4 tends to a little depressing, I started listening to Radio 3 and heard this viola da gamba music composed by Carl Friedrich Abel, “The Drexel Manuscript” and played by Paolo Pandolfo. I had to buy the CD and have been playing it constantly in the workshop this week. Absolutely amazing!! Put in viola da gamba into YouTube an you’ll see this amazing instrument in action.

So how long does it take to make a guitar (Cittern) Part 4?

Now I’m up to 52 hours. Those 12 hours of work, since the last entry, have been just on the bindings and purflings. As you saw with the mandocello, this shape is a bit tricky: some of the rebates for the bindings and purflings have to be cut by hand; there are 56 separate pieces and 5 mitres that have to be carefully cut.


I always use wood (rather than plastic) for the bindings, therefore each piece has to be carefully bent on the bending iron to fit. Also I now tend to make up my own purflings from coloured veneers. So although it takes awhile you can see why - I hope!


What next?

During the initial stages of a build you can work on various components separately, but as the build progresses those components converge and you have to spend less time per working day on any one instrument. Using the cittern as an example; you fit and glue one piece of binding, you then have to wait a few hours for the glue to set before working on the next piece. The mandocello is still being polished so that gets an hour or two a day. So, you need to start the next one.

Remember the photo of the Snakewood? Well, I’ve just started some preparation for that guitar. This one is for yet another Andy, I seem to know so many Andy’s! Anyway this guitar for Andy D will have Indian Rosewood back and sides and a stripe of paua shell going down the centre of the back.

Having glued up the back and taken it down to 2.5mm I had to cut a slot 1.3mm deep and 3.7mm wide to take the shell and lines of sycamore and rosewood. One of the challenging aspects of instrument making is that you work to engineering tolerances in a material that its maker didn’t design it to be used in such a way!

The slot had to be 3.7mm wide, my nearest router cutter is 3.2 mm. You can’t force something like this so the slot has to be spot on and you have to allow room for the adhesive too. If you force it, you split the back - you only make that mistake once!

The first cut is straight forward, clamp a straight edge to the back and make sure that the router is firmly held against it and away you go. The second cut is trickier, how do you move the straight edge 0.5mm and keep it parallel to the first cut? Answer, you don’t! After some head scratching I used some strips of heavy duty tape stuck to the side of the router’s base. Each strip was 0.17mm thick so this allowed me to slowly increase the width of the slot until it reached the perfect width.

Links

You can see that I’ve added a few more links to the side bar. One is for the “UnpluggedShop” to quote from it, “This site is about working with hand tools as a hobby and is dedicated especially to computer programmers, scientists, clergy, business administrators, truck drivers, CEOs, undertakers and those of all professions who need to get out more and get a life doing something relaxing with their hands. That is what Therapeutic Woodworking™ is all about.”

There is some wonderful stuff there for anyone interested in fine woodworking. I’m pleased that they find my blog interesting enough to track!

There is also a link to a forum called Just for Luthiers - one of many forums on the Acoustic Magazine website. I started contributing to it a while ago and there can be interesting debates about guitar construction. However, it occurs to me that forums such as these and the internet in general leads to a homogeneous world of lutherie where, just because large US manufactures do something, everyone else has to follow. What many fledgling guitar makers do not take on board is that a manufacturer of guitars (or any other consumer product) will usually evolve a technique of construction that suits there manufacturing requirements and create spin around it to justify its use. Individual luthiers do not have these constraints and should be constructing instruments that reflect their creativity and ingenuity. If I want inspiration I look to past masters or original thinkers such as Andy Manson and not the major US companies.