Shimming a bolt-on neck

Steverino

Steverino

black sheep
I've never done this before, but damned if it didn't work beautifully. I have a partscaster that I couldn't set up correctly. I'm not an expert in setting up guitars, so I wasn't sure what the problem was or how to fix it. The neck looked straight, Intonation was impossible, action wasn't acceptable. I tried just about everything else. I watched a couple of videos on shims so I tried it.
I got it backwards the first time, put the shim into the wrong end of the pocket, and that made it much worse. But when I got it right, everything else seemed to fall in place. The action was much better all the way up the fretboard and intonation was suddenly manageable. After a few more tweaks I think I got this one playing better than a few others I have. I may have to look at them a little closer now.
 
I've seen people say shimming is bad, but my main guitar has a shim and it plays amazing, so I don't care. My old tech set it up and he put the shim on the side furthest from the body, which isn't where I thought you shimmed a neck, but it made it awesome. I just shimmed a neck for @Guitar Heel and I think it made the action way better, but I put the shim against the body.
 
Chad said:
I've seen people say shimming is bad, but my main guitar has a shim and it plays amazing, so I don't care. My old tech set it up and he put the shim on the side furthest from the body, which isn't where I thought you shimmed a neck, but it made it awesome. I just shimmed a neck for @Guitar Heel and I think it made the action way better, but I put the shim against the body.
Click to expand...
What was surprising to me was how such a small thickness of a shim could make such a huge difference.
 
i've been shimming strat and tele necks since the 70's. in fact IN the 70's almost all strat necks needed shimming if you wanted low action strings.
i've also side pocket shimmed some of those 3 bolt 70's necks to keep them from shifting back and forth.
i've used everything for shims. picks, cut up credit cards, split match sticks, strips of wood veneer, you name it.
 
mongooz said:
i've been shimming strat and tele necks since the 70's. in fact IN the 70's almost all strat necks needed shimming if you wanted low action strings.
i've also side pocket shimmed some of those 3 bolt 70's necks to keep them from shifting back and forth.
i've used everything for shims. picks, cut up credit cards, split match sticks, strips of wood veneer, you name it.
Click to expand...
I wondered about the side shimming, if it was ever an issue.
 
Steverino said:
I wondered about the side shimming, if it was ever an issue.
Click to expand...
it was back then. the 3 bolt necks could be problematic. and sometimes when you get a replacement neck or are building parts-casters you need to do some side shimming. especially if you're getting the body and neck from different makers. i've also had to sand out a few neck pockets to get the neck to go in.
 
which end you put the shim on (front or back) depends on which way you want to tilt the neck

(it's pretty straightforward if you think about it - a (partial) shim near the body end of the pocket is going to tilt the headstock back; a shim near the neck end of the pocket is going to tilt the headstock forward
 
mongooz said:
it was back then. the 3 bolt necks could be problematic. and sometimes when you get a replacement neck or are building parts-casters you need to do some side shimming. especially if you're getting the body and neck from different makers. i've also had to sand out a few neck pockets to get the neck to go in.
Click to expand...
The one I'm working on is for a guy who is visually impaired. I've been working on it, and I just couldn't get it right. I'd work/play on it, leave it for a day or so, then come back. Yesterday, I tried the shim thing. It worked. I think it's ready now.
 
yabba said:
which end you put the shim on (front or back) depends on which way you want to tilt the neck

(it's pretty straightforward if you think about it - a (partial) shim near the body end of the pocket is going to tilt the headstock back; a shim near the neck end of the pocket is going to tilt the headstock forward
Click to expand...

Initially, I placed it in the neck end. Boy was that wrong.
 
Chad said:
I've seen people say shimming is bad, but my main guitar has a shim and it plays amazing, so I don't care...
Click to expand...

Shimming itself isn't bad... it's HOW a neck is shimmed.

I've seen shims of cardboard, plastic, balsa, aluminum... from tiny triangles to slim rectangles, to full pocket shims.

The primary issue is not to compromise the stability or surface contact of the neck in the pocket. You'd be amazed at how much better a guitar sounds when a bunch of shitty shims are removed and replaced with one good sculpted shim.

When I've needed to shim a neck, my go-to is to create one that fits in the bottom of the pocket and has holes where the neck screws go through so there's no possible way for the shim to move.

If you need a big shim, you can make it out of a hard wood like maple or rosewood and then sand it down so it's raised on one end and paper thin on the other. Most times I don't need that much, so my secret shim source is those thin metal "for sale" signs from the hardware store. I'll cut them with shears, lightly sand the edges to prevent cuts on the fingers of future repairmen, and then tap neck screw holes with a punch or small drill bit. Usually one of my metal shims goes from the end of the neck pocket to mid way up the pocket, then the mid edge is filed so it doesn't create a bump or a ridge on the underside of the neck. If more is needed, that metal is thin enough to be folded, then cut so the heel goes from no shim, one sheet, two sheets closest to the neck pickup. The folded part is usually down so the top of the shim is smooth against the neck. Less air gaps in the neck is a tighter fit and more resonance.

Same goes for thin side shims that fit between the bass side of the neck and that upper half of the neck pocket. They're cut to fit, not poke out anywhere, filed so no edge where the corner of the neck gets tight, and I usually take a sharpie and color the top edge so it doesn't glint when light hits the edge of the neck pocket.

You can ask @Guitar Heel because I'm pretty sure I had to do that with the Charvel that got the neck heel broken in shipping and I rebuilt it.
 
baimun said:
You'd be amazed at how much better a guitar sounds when a bunch of shitty shims are removed and replaced with one good sculpted shim.

When I've needed to shim a neck, my go-to is to create one that fits in the bottom of the pocket and has holes where the neck screws go through so there's no possible way for the shim to move.

Most times I don't need that much, so my secret shim source is those thin metal "for sale" signs from the hardware store. I'll cut them with shears, lightly sand the edges to prevent cuts on the fingers of future repairmen, and then tap neck screw holes with a punch or small drill bit. Usually one of my metal shims goes from the end of the neck pocket to mid way up the pocket, then the mid edge is filed so it doesn't create a bump or a ridge on the underside of the neck. If more is needed, that metal is thin enough to be folded, then cut so the heel goes from no shim, one sheet, two sheets closest to the neck pickup. The folded part is usually down so the top of the shim is smooth against the neck. Less air gaps in the neck is a tighter fit and more resonance.

Same goes for thin side shims that fit between the bass side of the neck and that upper half of the neck pocket. They're cut to fit, not poke out anywhere, filed so no edge where the corner of the neck gets tight, and I usually take a sharpie and color the top edge so it doesn't glint when light hits the edge of the neck pocket.

You can ask @Guitar Heel because I'm pretty sure I had to do that with the Charvel that got the neck heel broken in shipping and I rebuilt it.
Click to expand...

Good stuff. Thanks. I hadn't considered most of the points you made. I did use a paper hole punch for 2 screw holes.
 
You must log in or register to reply here.
Back
Top