Thursday 4 August 2011

Week 1 . . . Day 4

Context . . .
Well , we are at day four of our 22 day guitar-building course – so that is approximately 18% of the allotted time and we are all delighted with our progress to date.  And I am relieved that the English summer has finally arrived – I could hear rain on the trees when I woke up this morning and it did not stop until well after lunchtime. 
As mentioned in previous posts, Patrick has been focussing on his back, Phil on his sides and me on the front – although there has been considerable overlap and duplication of tasks as events have unfolded.  When I got to the studio I could see Phil already inside and hard at work . . . I needed to bang on the window so he could let me into the building.  We each have a key to the studio but not the building – but being the cunning Yorkshireman he is, he has ‘discovered’ that the doors at the other end of the building are open very early and you can get to the studio by going upstairs and along the passage. 
And speaking of the building, my ‘work station' is about one metre behind a sign that says there was ‘continuous brewing from 1739 to 1959’ in the buildings – so it is little wonder that Phil and I have ‘a pint’ after work each day . . . there are so many pubs and ales to be explored and tasted!!

A sense of history
On with the Build . . .
My first task this morning involved taking my back out of the Gobar box and looking at it lovingly for a while – and then planing the gutter brace down to a nice rounded shape.  This task involved using a ‘block plane’ and a very small luthier’s thumb plane to get rid of the bulk of the structure – of course being very careful not to interfere with the inside of the back, especially where it will be visible through the sound hole. 
Using the block plane

Using the luthier's thumb plane

The next tasks involved little more skill than looking adoringly at the semi-prepared back . . . I needed to rout some braces for the front using the 15’ (that’s feet in case you were wondering!) radius jig and get them ready for insertion.  It was a surprisingly easy task once the pieces of wood were set up in the jig. 
Routing the braces

Semi – formal chat . . .
As I got to the point of getting my braces ready for attachment to the front – or the sound box – Richard called a ‘gather around’ to discuss the various principles involved.  It seems that every luthier and ‘manufacturer’ has their own view about where and how the braces should be put on underneath the top.
In essence, it comes down to how tight or loose the builder wants the top to be . . .  while retaining structural integrity, of course.  `Richard chooses to put the X-brace (the big ones) reasonably high on the guitar so as to leave decent sized area at the bottom for the sound to vibrate the top.  The finger and tone braces (smaller ones) fill in most of the other spaces towards the bottom of the guitar – and these are ‘loaded’ according the ‘bass’ and ‘treble’ sides of the guitar to either enhance or hold those frequencies according to the kind of sound the builder has in mind.  It all makes sense when listening to the explanation – but I suspect that the actual placement of the braces is yet another ‘dark art’ that is learned from experience after many years of making guitars.

Bracing options
On with the Braces . . .
My next step involved ‘sanding’ the now cut and routed curved edges of the X-brace.  This is done using the 15’ sanding dish – and very carefully (like most things we are doing!) back and forward a few times, rotating the brace 45 degrees and doing it all again and again until you are happy with the surface. I then sanded the tone and finger braces in the same manner.
Back to the Back Braces . . .
Now the nerve-wracking bit – again!!  I now needed to cut grooves in the centre graft to allow the back braces to pass through.  This involved a very special technique of using the chisel to cut a few lines through the graft (on the waste side) while moving towards the marking ruler – and then doing the same of the other side of the channel.  A small 6mm chisel is then used to wiggle the excess graft out and clean it up.
Sounds simple right – but it wasn’t and I nearly freaked out at one stage when I used the chisel the wrong was around to cut the groove.  But everything turned out just fine as luckily I had not sanded the braces ‘exactly’ the same depth and I was able to swap a few of them around to get an excellent fit.   Finally put the entire structure into the Gobah Box and glued and clamped the braces into position – and then started breathing again!



Roughly trimmed to size

Getting ready to do the back braces



Braces in the Gobar Box
Preparing the X-Brace . . .
The next step involved preparing and gluing the X-brace onto the back of the top.  The first task was to very carefully (there I go again!) cut a groove at 110 degrees half way through one of the braces and then cleaning it out with the 6mm chisel.   The second task was to do the same thing on the other brace (remembering to cut the curved surface this time!) and again cleaning it out with the chisel.  I managed to get my joint pretty much perfect – but only after working on it for about 45 minutes! 
Sanding the X-brace

Once the brace was prepared and glued I used the 15’ radius sander to smooth off the top surfaces to get a nice finish to go against the guitar.
One of the things I am learning in this course is that the level of accuracy and care needed is very high.  I have done a million joints like this over the years and I have been pleased with my level of workmanship – but this is at a whole new level!  And the tools we are using are also very important – for example the Japanese saw that I used to cut these grooves is a thing a great beauty and really just needs its own weight to easily cut through the light spruce.
Today’s  Chat . . .
Nick Benjamin popped up to the workshop in the late morning just as we were stopping for a coffee which prompted a discussion about the significant differences in guitar manufacturing.  Fundamentally, what we are doing is the ‘American’ method of steel string guitar making – which basically involves building a box and neck separately, finishing them with lacquer and then attaching the two.  There is also some kind of truss rod (which runs inside the neck) so minor adjustments can be made over the life of the guitar. There are some different ways to attach the neck (special joints, bolts and the like), but key thing is that there will always be a ‘line’ in the lacquer where the two components come together.
The other main way is used for Spanish guitars – which basically means that the neck is built into the guitar during the construction phase.  A groove is cut into inside of the neck into which the sides of the guitar slot.  There are also significant differences in the bracing of the front and back of the guitar – and the way in which the sides are supported and attach to the top and bottom – and of course there is no truss rod.  The guitar is lacquered as one – so there is no line where the neck meets the rest of the guitar.
There is no reason why either method cannot be used for the other type of guitar – other than tradition, it would seem?

Spanish guitar neck

Entirely different method of construction
We also learned about the 'traditional' methods of making rosettes - basically the very detailed patterns are made up by laying very fine strips or 'pipes' of wood (or other materials) lengthwise and builing up a pattern at the end of the structure.  Once it is all glued firmly in place a very fine saw is used to cut very thin slices - which are then laid end to end to form the circle.  Of course each part needs to be slightly wedge shaped so it can form the circle - and all this for something that does not make any difference at all to the sound!

Sticking on the X-Brace . . .
This task might sound simple . . . but getting the X-brace in exactly the right position involves some care.  Before starting you need to mark where the bridge (where the strings connect to the guitar) will go (on the other side of course) and also mark five other reference points that the X-brace needs to touch – and it takes some jiggling around to get it in exactly the right spot.
Once you are confident you have right spots marked then it is time to put it back into the Gobar Box and ‘in one smooth and confident movement’ place the glued X-brace on the top – without sliding it around and spreading the glue everywhere!  Mine went down well.

X-brace in the Gobar Box
The Neck Brace . . .
My last task of the day was to return to ‘something I had prepared earlier’ – the neck brace.  The course is very well constructed in this regard – while we are each focussing on a different main task we can always get on with preparing something if there is a little downtime.
I had already planed a very accurate beautiful smooth 3 degree angle on my block – or so I thought!  Richard ran his special ruler over it and there were a few high and low spots that needed adjusting.  I then marked a couple of holes 15mm and 50mm down from the special surface and drilled in effect two holes in the one hole. 
After using the bradawl to mark the hole, the first stage involved using the 16mm bit to drill down to the marked gauge.  Then the rest of the hole was completed with a 7mm drill.  Luckily this is a relatively simple task!
Finally I marked  a 5mm chamfer on either side of the block and used the block plane to remove the excess wood – another simple and stress free task! 
Something simple at last!

That said, it has emerged that my planing technique needs some adjustment as I apparently have the habit of going down at the end of the stroke (despite actually pulling the plane up).  The correct technique involves starting the stroke with the weight on the front hand and transferring it to the back hand by the end of the sweep and following through evenly – something that I am not doing correctly!
The Others . . .
Patrick continued to quietly achieve various tasks – but most exciting was the reveal of his ‘bling’ rosette.  As always this sent a wave of excitement around the workshop – we all enjoy each other’s successes.  At various other times during the day I saw him working his neck, neck blocks and removing the sound hole in his top – another very exciting moment for all of us.  His top did not need much thicknessing (I still find that word weird) so he had to use a scalpel for the final stages of the sound hole.

Patrick's bling!

Scalloping the braces

Very pleasing!

It had to be done!

Sanding the sound hole


Working on the neck


More neck work

Phil made great progress with his sides AND his very own special rosette.  Listening into Phil’s conversations with Richard gave me a good insight into what is in store for me with the sides – and how complicated it is getting the right taper in the guitar.  We are dealing with some very complex curves and tapers – and magically they all need come together.  Richard also used Phil’s kerfing job to demonstrate how it is done – which is basically gluing rows of slotted strips of wood around the top and bottom edges of the guitar.  Phil also needed to start a new neck as Richard discovered a crack – so he gets even more practice at preparing two angular surfaces on the same plane!

Cutting the rosette

Very well clamped rosette

Sides in the mould

Starting the taper

Back to the rosette

A man in a hurry!

Looking like a guitar

Kerfing demonstration

Who's a clever boy then!

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