Shimming in a non-square neck pocket

[Dave O'Heare]

I've a question regarding shimming a bolt-on Fender-style neck.

I recently bought a NOS Brownsville 12-string. It's a low-buck guitar, built a lot like a Danelectro with an outer and center frame of plywood and a top and back of Masonite or something. All in all it's an okay instrument (I bought one of their 6-strings at a Boxing Day sale a few years back, and it's fun).

I can't get the action low enough to be really playable; with the saddles sitting on the bridge plate it's still too high. The relief in the neck is okay, the frets are okay, no problems there. I suspect that it sat strung up to pitch for several years in a not-well-controlled warehouse atmosphere.

Normally I'd just put in a shim, but the neck joint isn't square; it's cut away on the treble side for better access to the dusty end of the neck, I suppose. Looks like this:

not my guitar, but same instrument.

Thoughts, folks?

[Brian Evans]

I would make a completely normal square shim, adjust it to where you want the neck to sit, then scribe and trim to match the body curve.

Brian

[Freeman Keller]

It has been my limited experience that normally you need a shim that is thicker in the back of the pocket (towards the bridge) and tapers to nothing at the front (ie you want a little more angle to the neck to bring the string plane down). I would do as Brian suggest and make a normal square shim, drill it to fit your pattern and then trim the front and side in the cutaway. You will have a slight edge of the shim material visible (I use maple) - you might want to put a tiny bit of lacquer on it or try to paint to match the body.

[Dave O'Heare]

Thanks, folks. I got stuck on the old-school thought of shimming just at the back of the pocket, and figured that that would just be a bad idea...

[Peter Wilcox]

Thanks, folks. I got stuck on the old-school thought of shimming just at the back of the pocket, and figured that that would just be a bad idea...

I think that would work just fine, and a little air gap in a guitar of this quality wouldn't matter (to me.) Besides it wouldn't be visible while you're playing it.

[Freeman Keller]

Thanks, folks. I got stuck on the old-school thought of shimming just at the back of the pocket, and figured that that would just be a bad idea...

I think it would be a bad idea. If you did that and tightened the front screws it seems like it would torque the neck towards the cutaway. I would make a full size shim, taper it to the front and then shape it.

[Dave O'Heare]

Thanks, folks. I got stuck on the old-school thought of shimming just at the back of the pocket, and figured that that would just be a bad idea...

I think that would work just fine, and a little air gap in a guitar of this quality wouldn't matter (to me.) Besides it wouldn't be visible while you're playing it.

As Freeman put it, I'm worried about the torque toward the cutaway. As well, having seen my share of Strats and similar with a ski jump at the end of the neck, I really ought to know better.

In fact, I think I'll make that my MIMF signature!

[Peter Wilcox]

Yeah, now I see what you guys mean - better to make the full sized shim.

[Gordon Bellerose]

Most people shim to get a bit more height, to match up with a bridge.
You can attain the same thing by filing the neck pocket down at the front edge, while leaving the back of the pocket at the same height.
This gets you the angle you need, without having to look at a shim.

It is critical to maintain a flat surface if you choose to go this route.
You generally don't have to file a lot off.

[Dave O'Heare]

Most people shim to get a bit more height, to match up with a bridge.
You can attain the same thing by filing the neck pocket down at the front edge, while leaving the back of the pocket at the same height.
This gets you the angle you need, without having to look at a shim.

It is critical to maintain a flat surface if you choose to go this route.
You generally don't have to file a lot off.

Gordon, thanks for that option!

I'm just a touch leery of the solidity of the whole neck joint; I don't really want to start removing material if I don't have to. Besides, I know my skills well enough that I'd be going "Sheesh, cut it three times and it's still too short!"

[Steve Sawyer]

Just lurking on this thread here, but wanted to suggest that there is a technique I and others have used in making a tapered recess near the bottom of legs on arts & crafts furniture that would be perfect for adjusting that pocket without relying on shims (see the tiny pic below).

Make a simple sled or template to rest atop the body just as if you were routing out the pocket. Slip a credit- or business-card (or feeler gauge or whatever) beneath the template in the neighborhood of the pickups to put a slight angle on the template, adjust your router bit so it barely touches the bottom of the neck pocket up against the body, then rout the bottom of the pocket creating the angle. Remove template, clamp neck in place and check the position. If necessary, repeat adding additional cards until you've achieved the correct angle.

Craftsman Table Leg.jpg (6.75 KiB) Viewed 14266 times

[Bob Francis]

Just lurking on this thread here, but wanted to suggest that there is a technique I and others have used in making a tapered recess near the bottom of legs on arts & crafts furniture that would be perfect for adjusting that pocket without relying on shims (see the tiny pic below).

Make a simple sled or template to rest atop the body just as if you were routing out the pocket. Slip a credit- or business-card (or feeler gauge or whatever) beneath the template in the neighborhood of the pickups to put a slight angle on the template, adjust your router bit so it barely touches the bottom of the neck pocket up against the body, then rout the bottom of the pocket creating the angle. Remove template, clamp neck in place and check the position. If necessary, repeat adding additional cards until you've achieved the correct angle.

Craftsman Table Leg.jpg

Great tip!

[Gordon Bellerose]

Just lurking on this thread here, but wanted to suggest that there is a technique I and others have used in making a tapered recess near the bottom of legs on arts & crafts furniture that would be perfect for adjusting that pocket without relying on shims (see the tiny pic below).

Make a simple sled or template to rest atop the body just as if you were routing out the pocket. Slip a credit- or business-card (or feeler gauge or whatever) beneath the template in the neighborhood of the pickups to put a slight angle on the template, adjust your router bit so it barely touches the bottom of the neck pocket up against the body, then rout the bottom of the pocket creating the angle. Remove template, clamp neck in place and check the position. If necessary, repeat adding additional cards until you've achieved the correct angle.

Craftsman Table Leg.jpg

I have also used this method and it definitely works, but is considerably more work.
I make templates for almost everything anyway, and if the OP is going to be building a couple of guitars it is worth the extra effort.
For a one time repair I would still use a rasp and file it down.

My method for doing this goes like this.
1. Mask off the body around the neck pocket, about 1/32" (or as much as you think necessary) down from the edge at the front, tapering to nothing as you go back. This gives you a working line, and protects the finish from chipping.
2. Use the rasp to get the front edge down to the tape, and then level the pocket back to the rear edge.

Works for me, and it only takes about 1/2 hour.
I realize that it is a bit tricky for the rounded pocket, but with care it can be done fairly quickly.