Preparing the Neck Blanks
In the continuing saga of my attempt to build a pair of guitars, it is time now to turn my attention to the guitars' necks...
Guitar necks are in my opinion the heart of the guitar - the rest just make it handier to use them. They are also great works of engineering - built to hold some strings for the hand to play, and at such close tolerances. This was not as big of a feat with early guitars - they used gut strings that did not put a lot of tension on the neck. The 20th century brought new technologies - such as steel strings - into the mix. Steel strings are one of the reasons an electric guitar is possible - it is the vibrating steel string that affects the electro-magnetic field created by the pickups that allows the guitar to be amplified by something that isn't a microphone and therefore clearer and not requiring the noise generating qualities of an acoustic guitar.
I say "noise" because that's me playing ;-)
A side affect of these new technologies is that they create a lot more tension on the neck, which if left unchecked would tend to warp the neck. The first line of defense against this warpage is to use a stable, high tensile strength wood. Mahogany is one such wood, and is popular among many makers. Fender uses maple in many of their necks, and it's an excellent choice for a neck wood - relatively inexpensive, it's also close-grained (no filling) and is a very strong wood.
Steel is stronger, however - and relentless. Even maple has difficulty maintaining those close tolerances after years of use. Guitar makers decided to fight steel - with steel. Sometime in the late 19th or early 20th century, they began experimenting with something called a truss rod. The truss rod is a steel rod, usually threaded, that is installed into the neck in such a way as to counteract the tension created by the strings. Here's a plan for a Tele-style neck showing a traditional truss rod in place:You can see it has a slight curve to it - the truss rod is a essentially a metal rod, with one end solidly mounted to the neck and the other end threaded with a nut. You tighten the nut down to increase tension on the neck in the opposite direction of the way the strings pull on the neck. Hence the curve. The Tele neck and truss rod is an older version, sometimes called a "vintage style", where the top is permanently attached and the adjustment (the threaded part of the truss rod) is done at the heel or bottom of the neck, next to the pickups.
A later version of these truss rods mounts the rod solid at the heel, and the adjustment is done through a hole in the headstock. The diagram for this style looks quite similar with only a few minor - but important - differences. It is still the same arched path, however:
There are many other types of truss rod designs, but these are the two I am going to use on this project. I will get more into the design of these rods later, but I wanted to lay the groundwork here so there was some understanding as to what the heck it is I am up to, as routing the channel into which the truss rod is laid is one of the first steps in building the neck. Later, after the truss rod is installed, a contrasting colored cap is installed over it, which I will get into in a later post.
To route this curved channel, I built a simple router sled to hold a 1" thick piece of maple with a set of curved rails that match the required curve for the rod. A pair of stops is place to keep me from overshooting the mark, and I made a new base to fit the sled that fits my router.
I could use one of those custom router fences - but I don't own one... In that case I wouldn't need to make a special base, but then again, they cost money and the base can be made for nothing out of scrap material.
To make it slide more easily on the sled, I apply a little wax to the rails. The stops are held in place just with a couple screws. I started off by taking the shallowest cut, and adjusted the router to take a little more with each pass. All to route a simple, 1/4" wide slot with a slight curve.
With all that work, you would think the process would be almost foolproof, wouldn't you? Well - not with me around.
I was about halfway through routing the first channel when I heard a loud ZZZINNG! I shut off the router and picked it up after it stopped spinning. The router bit stayed in the wood.
UGH! I guess it's a good thing this was not a highly prized maple board. After that, I decided to take a slightly different path. I decided I would make 3 necks. Yes, three necks, for two guitars.
The reason being that I didn't have any other maple on hand, save for this one piece of 6/4 maple I had on hand that I have that was originally purchased from a lumberyard back in 1954. Yep. Prized maple. What a fool I must be to trust myself with a router on that... We'll see how it goes...
The third neck would be the remaining cheaper board I had started - I would use it as a practice piece. If it turns out, I'll have an extra neck and I can whip together a body at some point to put it on. If not - well I'd rather put a little extra work in than to mess up the prized maple.
This particular piece of maple has some awesome birds eye on it - on the other end, but not on the end I used. So I still have the better (literally!) part of the board for future necks. Unless I completely screw these up and bury the board for another 50 years. If I mess it up, I'll be too scared to do anything with it...
Once I had the slots routed, it was off to the bandsaw with the blanks to cut them to the drawn outline, then over to the spindle sander to get them as close to the outline as possible, then over to the router table to route them flush.
Instead of screwing the template to the wood, I used some "heavy duty" double sided tape. I was a bit nervous about it coming loose, so I tried it out on the test piece first to see how well it worked.
I needn't have worried. It was definitely heavy duty stuff - I thought I was going to break the template trying to peel it off of the wood. Strong stuff - I've used some stuff that was garbage, this tape was definitely good.
While the template was still attached I drilled the holes for the tuning machines - a set of Gotoh Vintage tuners from Warmoth for each, 11/32" holes with a 4 11/16" spacing.
I must say - working with the vintage wood right next to the new stuff - that old stuff is a dream to work with. It feels denser, it machines more cleanly, it just seems way more solid - you can see in the photo how much lighter the new stuff is in color. The next part will cover finishing the truss rod installation, including drilling the hole in the headstock... It's sure to be nerve-wracking!