Monday, February 9, 2009

New guitar update, Neck build up

I think more work goes into the neck than any other aspect of the guitar. Especially on an electric.

For truss rod installation I can but follow the manufacturer's instructions. I use the Allied Luthier's Supply, stainless steel, two way adjustable, low torque rod. It is roughed up with a file.The neck is dadoed for a very snug fit. And a hardwood spline is fitted over the top.


The filler strip is epoxied in place with light pressure. The strip sinks in more at the center as the rod is compressed against the adjusting screw. During clamping I check the action of the nut to get it tight, but still free.

Once the epoxy has cured the strip is pared and scraped flush. Note the walnut plug that fills the end of the dado at the body end and acts as a stop for the truss rod end.
The fingerboard marquetry is fully cured prior to laminating the boards. The three layers of veneer are pinned to mdf cauls and clamped up. The laminations are left under pressure for about 2 days. It is very important to keep the boards flat until they are fully cured.
This process produces a very flat and stiff finger board. The edges are cleaned up on the edge sander and the nut end is checked for square.
Fret positions are then marked off on the board. This clamping arrangement of the scale allows for hands free marking. I made my fret slotting saw from an old back saw. By carefully filing and sanding the blade along just the bottom 1/2" I achieved a very stiff blade with the perfect sized kerf. I filed a dozuki style tooth and it cuts on the pull stroke. Even so, it requires great care and concentration as no mistakes can be made. Note the pine strips that act as a depth stop. When the blade just scores these carefully thicknessed strips the slot is the correct depth. The actual kerf stops just past halfway through the middle layer of veneer. This leaves a lamination below the kerfs, running the full length of the board.
Once the boards are slotted, they are tapered on the edge sander to their final dimensions. Both the finger board and the neck are left long at the body end to accommodate veneer pins. These are just #19 1/2" brads with the heads snipped off. Note the stack of three finger boards in the back. Nice and flat, no?
A carefully shaped Ash caul is used to laminate the fingerboard to the neck. Precision is of the utmost importance. The center is checked and rechecked, then checked again. But the pins prevent most movement and lots of glue can be used. Once the board is fully cured it is cut through at the 22nd fret. The waste is carefully pared away, and the pins removed.
This gives me a first hand look at the laminate bond of the fingerboard. My process results in one of great strength, I think.In the rebate that is formed by the fingerboard the neck bindings are laminated with the use of a tapered and waxed spline.The ends are mitered and the mitered end cap is glued in place with this little set up. Nice, no? The maple binding is very springy and there is clamping pressure to spare. When the glue is cured the bindings are rasped flush with the board.Headstock veneers are precut for the truss rod nut and carefully scraped smooth on the back.
The headstock wood and veneer are oversized to allow the placement of more veneer pins. A temporary waxed wood nut is used for alignment. The nut end of the veneer is also pre shaped to the correct angle. This is done by hand on the edge sander. It is offered up to the wooden nut for a perfect fit.

To make laminating the headstock easier the caul is glued together and faced with wax paper to be applied as a single unit. Using 4 veneer pins ensures a precise placement.
Binding the headstock is a bit more tricky. Once the headstock is sanded to shape, a purfling cutter is used to score for the rebate.


Great care is taken to ensure that no tearout occurs at the corners.
The waste is then chiseled out. Very carefully, as no mistakes can be made.
The rebate is made perfectly square and smooth with a paring stroke. Headstock veneers such as this cherry burl, would be shattered by a router. Note the cross grain at the corner. I think maybe this is only possible by hand.


Bindings for the headstock have to be bent. I use this little set up. The pipe has an old chore boy stuffed in the end for a difuser.


It works well though, and it dosn't take long to shape the bindings.

The bindings are glued on in stages. I use a soft nylon cordage, wrapped tight for excellent clamping pressure.
Having lived on a sailboat, I know not to ever cut a line in two. But with this clamping set up the extra length can be put to use on the end bindings.
The successive stages are trimmed back with the dozuki saw.
Then the ends are pared back and filed flush in preparation for the next set.

The side bindings go on last.
Note the awesome squeezeout. This binding is on for good. The precision is such that there will be no need for even the tiniest amount of filler.
Glue won't stick to the nylon cordage either, just unwrap it and there it is.Once things are cleaned up with the rasp and riffler, things are starting to look very good, I think. Note how I leave the neck square for most of it's length. This makes clamping in the vice for bindings very easy.
That's all for now. Next time we should see some carved necks and maybe something that even resembles a guitar.
IW

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