Evo Pro Build Diary – Part 9
Things have been a bit hectic of late so apologies for being a bit slow in progressing with the build diary. Now we jump into the all important neck carving and fretting stage. From my point of view, as a luthier, this is the stage where a guitar blossoms or dies. A bit like when you have a bit of something stuck in your gum, it feels big on your tongue but may be like a grain of sand. If the neck isn’t right or, flawed in any way your hands will tell you when you play. It may sound great but, if it doesn’t feel right…
Using a ball nosed cutter to rough the neck carving out.
With machining developments I am now able to repeatedly carve a neck to about 1mm oversize. Some may ask why I don’t carve it to it’s finished shape? Well for me a custom or bespoke guitar is just that, made to fit the player. So I carve oversize and finish off with rasps and scrapers to get as close as possible to the profile the individual desires. The initial carving still saves me time but more importantly offers me a perfect reference plane for finishing off the profiling. Once the initial machining is complete I get to work with rasps and scrapers to achieve the desired feel.
Using a scraper to shave the neck to the desired profile.
Wenge is hard and quite brittle and doesn’t respond very well to a scraper, it also takes the edge off quite quickly. When I am close to where I want to be, I finish off with some coarse sandpaper, lapped across the neck to even out any humps or flats left by the scraper.
Using coarse abrasive cloth to even out the final carve.
Now my attentions turn to the other side of the neck, the fingerboard needs to be cambered. I use several different radii for fingerboards, most are compound. That is, the fingerboard radius flattens out as you progress up the board. This helps to avoid the problem of choking while bending strings (if the action is fairly low), so common with many mass produced instruments and generally improves playability as the action is more consistent moving up the register. This fingerboard is going to be compound from 12″ radius at the nut to approx 20″ at the 24th fret.
Using a plane to shoot the rough camber on the fingerboard.
Once the camber has been roughed out, I use a carved radius block (compound) loaded with coarse abrasive to even out the shape. This is done using a side to side, rocking motion rather than sanding up and down which would result in loosing the compound nature of the fretboard.
Finishing the compound camber with a custom made radius block.
Once the fretboard radius is complete I can mark, drill and fit the position markers. In this case I am using plain mother of pearl dots, graduated from 6mm to the 12th fret and 5mm from then on. I drill holes at the marked out positions using a hand drill and ‘lip and spur’ drill bits that are slightly dull, this helps to prevent tearing around the hole edges as the drill bit enters the work.
Drilling holes for the position markers with a hand drill.
The pearl dots are glued and lightly tapped into the holes until they are just proud of the fretboard surface. The tops are then dressed away with a flat abrasive block. I go through a few grades of abrasive until all sanding marks from the radius block are removed. Not enough material is lost to affect the camber created previously.
Gluing and taping the Mother of Pearl markers into the holes.
I can now fret the neck. As this neck is bound I need to trim the tang off the fretwire where it crosses the binding. This is done using a specialist tang cutter, and for the most part it performs admirably. Some sizes of fret wire require cleaning up with a file after trimming. I still fit my fret wire in the traditional way, though I may well move to pressing frets in the near future. It takes practice and technique to seat a fret properly without it lifting back out of the fret slot. I dread to think how many frets I have fitted over the years!
Using a hammer to seat the frets.
Once the frets are seated I trim off the excess with a pair of ‘true’ flush cutters and then dress the chamfer on the ends of the frets. I do this with a block that holds a file at a specific angle. It’s quick to do and very consistent.
Using a home made chamfering block to dress the fret ends.
Now the fretting is complete I can finish off the neck by carving and blending the volute, fitting side dots, nut, inlaying the logo and drilling the holes for the tuners etc.
The fretted and dotted neck, ready to be finished off.
Thats it for now, I’ll finish the neck off in the next article.