• Sam

Putting Your Neck On The Line

Okay, so the title is probably a lot more dramatic sounding than it needs to be - almost ClickBait in fact, but this article is about the process behind making an instrument neck, and I honestly couldn't think of anything else punny and appropriate involving the word "neck".

So what's so special about musical instrument necks that they warrant an entire blog post? Well, to many luthiers, both amateur and professional alike, the neck is a very intimidating job. It combines two very different woodworking disciplines, the accuracy of measurement that comes with traditional carpentry, and the more tactile approach that's associated with sculpture. We're combining accurate measurements and angles with the kind of complex carved curves than can only be appreciated properly the touch of a human hand.

For this reason, a lot of builders tend to build bodies - amazing bodies - but then marry them up with a third party factory made neck. This is something of a shame, as despite being intimidating, necks are surprisingly easy to make so long as you follow some very simple steps.

Bear in mind that the neck I'm going to show here is a rather simple one - it doesn't feature a truss rod for example. That's partly because it's a Bodhralele neck, and partly because this article is simply about the process of shaping the neck.

Of course, any woodworking project starts out life as a lump of wood, in this case a 2" thick plank of beech.

We need to go all the way back to our old technical drawing classes in our school days and start to think of orthographic drawings. In this case, we're thinking about the side projection of the neck. This needs to be drawn out onto the wood with the grain running along the neck length for strength.

Here at BTLX, we don't use a scarf joint where the headstock meets the neck, as continuous grain will always be stronger than a glued joint. Instead we use a 10 degree break angle for the headstock, then split the difference and offset the grain direction by 5 degrees so both the head and the neck have equal grain strength, with the maximum grain strength located at the weakest point.

Now comes the moment you've been waiting for. We start to make sawdust, or if you prefer, Man Glitter. Take your plank to your bandsaw, or if you don't have one, break out your trusty jigsaw or whatever you like to use to cut shapes, and cut the blank shape of your neck out of the plank. It's as simple as that. You should now be left with a very rough blank that conforms perfectly to the side profile shape of your neck.

A bit more finessing is needed though, so we need to go back to that orthographic drawing in our head again. This time focusing on the top elevation, specifically the headstock shape and the taper between the nut and the heel of the neck.

As well as going back to the old technical drawing classes, we also need to remember very first lesson in the "Big Book Of Luthiery" on page 1, paragraph 1 - Always respect your centreline.

So go ahead and draw on your centreline, then mark out the neck taper and headstock outline. At this point you should be able to start visualising how the neck is going to look when complete. Now simply take the piece to your saw again, and using the flat face where the fretboard will be fitted as your reference, cut the waste material away.

So you can now sit back and admire your work for a moment.

You've just created an instrument neck at this stage.

Okay, it's anything but pretty, but it's roughly the right shape and size, and at a pinch (if you're not afraid of splinters) you could just about use it to make a tune. But that's not good enough really is it? Lets face it, proper instrument necks have smooth flowing lines and curves. How on earth are we going to turn this rough cut rectangular chunk of wood into a smooth curving semi-circular profile?

It's a lot simpler than you might think - One word - Facets.

We draw a centreline down the back of the neck blank, effectively dividing it into two halves. And to avoid complication, we're only going to address one half at a time.

Now, halfway between the centreline and the edge corner of the neck, draw another line.

Okay, got that done - now draw another line on the side of the neck, halfway between the front and the back, just as in the photo.

Now clamp your neck at the edge of your bench, with the facets to be worked closest to you. The clamps should be positioned on the headstock and the heel to allow maximum access to the faceted area, but remember to provide adequate support for the headstock while clamping. The wedges left over when you cut the side profile are perfect for this as they are the exact right angle.

And now this is where the fun really begins. This is where you start to carve the neck, and slowly but surely the shape starts to reveal itself.

For this you're going to need a variety of tools, and to be honest, there is no hard and fast rule as to which you use. Some folks like to use a spokeshave, others prefer rasps and files, and still others opt for power carvers, dremels and angle grinders. Personally, I like rasps and files, and I find a Japanese Shinto Saw Rasp is one of the best tools for this job.

So what exactly is it we're going to do?

Well, you see that line you drew halfway between the centreline and the edge, and the other one running along the side? We're simply going to use our chosen tool to knock the corner away and join those two lines with a flat surface.

Now you'll notice that what we're doing here is changing the cross sectional shape from a regular rectangle, to a different polygonal shape with more sides.

Imagine if you drew a square on a piece of paper, then knocked off all four corners - you'd get an octagon, right? It's still very angular, but it's a bit more rounded than a square. Now imagine if you took all 8 of those corners, and knocked them off - you'd be left with a 16 sided polygon. Still angular in form, but getting closer again to that elusive circular shape.

So just as in the drawn example, we take our neck and we draw more lines that will allow us to facet the new corners that we've created. Simply draw more lines halfway between the centreline and the corner edges, and keep knocking the corners off with your chosen tool.

Repeat this process enough times and you'll end up with a roughly rounded neck profile that's starting to feel comfortable in your hand. Keep feeling it in your left hand as this is the best way to judge when you've got it just right.

Once you're satisfied with the shape, it's time to start refining the shape. Don't worry now, as the most scary part is behind you, and if you've stuck with it thus far, you've more or less nailed it.

Take your new neck and clamp it up by the heel on the edge of your bench, allowing the rest of it to stick out into the workshop, ensuring the curved side faces upwards.

Now go grab yourself a stool or a chair, as this next stage is best done sitting down, partly because it's going to take some time, and partly because you're going to use your own body as an additional clamp.

Position yourself right in front of the neck with your chest just about touching the headstock but not bearing any real pressure on it - just enough to secure it in place and stop it moving when you work with it.

Now take a strip of fairly coarse sandpaper with both hands. Holding it at both ends, drape it over the neck and pull it back and forth across the neck for however long it takes.

The motion you're trying to achieve here is the same as when you dry your own back with a towel after getting out of the shower. The further apart you hold your hands, the more the sanding pressure will be on the back of the neck. The closer you hold your hands, the more the sanding pressure will be on the sides of the neck. By combining these hand positions, working back and forth along the neck and feeling it regularly, you will quickly achieve a beautiful smooth rounded neck profile that feels comfortable in your hands.

Now you're into the home straits and galloping towards the finish line. You've just got a little finishing to do and these are best done with rasps, files and sandpaper. Just smoothing out the transitions between the neck and the heel, and refining the shape of the volute behind the headstock. Just work away at these gently with your files until you can see the shape emerging from the wood. Remember, all the shapes you want are already inside the wood. All you're doing is peeling away the outer layers to reveal them.

Work your way from the coarse rasp, to the finer metalworking file, to your sandpaper, working through the various grits until you have a surface as smooth as a baby's bum.