Stabilizing a three bolt neck

My buddy Jeff “Guitar” Nelson is not gentle with his guitars. He’s a hard player, bends the strings off the neck, and has very strong hands which he uses to mangle his guitar to within an inch of it’s life. So it came as no surprise that he was having trouble with his three bolt Stratocaster neck staying in place. He kept pulling it from side to side, and eventually the screw holes were completely thrashed.

The bolt on neck is actually a misnomer – it’s not bolted on at all: it’s screwed on. Screws thread directly into the wood; bolts thread into a metal component, like a nut or threaded insert. Regardless of whether the guitar has three screws or four, the problem is the same: the neck body joint is just two flat pieces of wood facing each other, and are solely reliant on how much torque is put on the screws to hold it in place. This isn’t the most stable of designs as it is, and couple that with the fact that maple is a fairly soft wood which the screws can strip out of quite easily, and you’ve got a recipe for disaster.

A few weeks ago I had converted Jeff’s Strat neck into a true bolt on, installing threaded inserts in the neck’s heel. Unfortunately, the wood around one of them gave way – the wood was somewhat compromised around the insert, and it tore out when the neck got smacked. It’s important to me that the things I fix STAY fixed, so this was a good opportunity for me to stand behind my work.

Here’s a shot of the heel with the threaded insert removed. There are two holes: the deeper one for the threaded insert, and shallow one was where the original metal plate for the neck tilt sat. The metal plate had to be removed to make room for the insert, and wasn’t a pertinent component anyway (the neck angle was fine as is). The brass insert was VERY secure (I broke several as I was screwing them into the wood here), but the wood around it gave way just the same. No fun!

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Now, I had to somehow fill these holes with new wood, which needed to be super strong to support a new threaded insert and not rip out when Jeff smacked his guitar around. I didn’t want to just use a dowel, as the grain orientation of the wood wouldn’t support that kind of torque. So, I bit the bullet and spent $130 on a set of specialized Veritas plug cutters, which would allow me to quickly make wood plugs of any grain orientation I wish.

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Phew! You know you might be a guitar tech if you’re willing to spend that kind of money on a tool that you might only use once…

With tools in hand, it was time to get started. I first drilled out the larger hole that had housed the metal tilt adjust plate, cutting deep into the neck so I’d have lots of wood on wood contact with the plug. I clamped the neck into a 18cm radius block to hold it flat on the drill press, flagged my bit (to keep from drilling too deep):

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Now that I had a nice smooth hole, it was time to cut a plug to fit. I had never used a plug cutter before, so I experimented on some scrap wood first, then started in on the bolivian rosewood I intended to use for the plugs. I opted to use the rosewood because it’s a very hard wood, and I knew it would handle the torque from the neck bolt, but holy cow cutting a plug from it took forever! I botched the first plug by cutting too fast, so for the second one I slowed WAY down. I must have spent 20 minutes just putting the slightest pressure on the drill press, so it would slowly shave off a tiny bit of wood and not seize up. [NOTE: rosewood dust is poisonous, so I wore a mask while I was cutting into it.]

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Once the plug was cut, I cut it free with the bandsaw:

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Presto! A perfectly cut plug!

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Here’s the plug glued in:

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The next few steps were to repeat the process, cutting a smaller hole where the insert tore out, overlapping with the new plug, and then filling that hole with a rosewood plug:

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Next I used a crazy sharp chisel to cut the plugs flush with the face of the heel:

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Fabulous! Now all I had to do was mark out and drill a new hole for the new brass insert and install it. These rosewood plugs are tough as nails, so this neck ain’t going nowhere.

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I put Jeff’s guitar back together, and tested my work by yanking on the neck back and forth – and it didn’t move. Awesome! I’m sure that this beauty will be safe in Jeff’s mitts.

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All done! This cost me $130 in new tools, required learning a new skill, and took a couple of hours to do – and I’m not charging Jeff a dime. While I don’t think that I can fully take the blame for the original brass insert tearing out, what I can do is take full responsibility and make it right. That’s just how I do.

 

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