Bolt on necks: To shim or not to shim, that is the question.

[jazzbow]

Hi all.
Have you taken a good look at your height adjustment screws lately? Not really too much of an issue if you strum and pick near the end of the neck/neck pickup area, but if yor mute with your palm or vigorously twang those strings then protruding screws can be a real pain.
Where F****r styled bolt on neck guitars are concerned we can improve this flaw quite easily by shimming the neck to give greater height to the string end/saddle part of your guitar.


MIM strat with lots of screw showing


Rosewood veneer shim for the back of the neck pocket.


Now compare the B, D & G string and that the curve of all the saddles mimic the fret board radius.

For the two E strings you can get shorter screws so as to lose what is still showing. The higher end F****rs should have these on.

[mattymel]

ideally no, but anyone that says they can hear a shim is lying. that being said, the picture above is THE biggest shim i have ever seen.

[jazzbow]

Now this is a really cheap and potentially nasty strat replica. Same thing, needs drastic shimming.


This guitar had lots of issues but it belongs to a friends grandson and it would have put him off learning guitar had it not been put right. Here we see the protruding screw issue.


Here's a rosewood shim. I have super glued it to this part of the neck for maximum relief, any further to the end of the neck pocket and the neck will be pitching in the wrong direction.


This pencil line was flush to the neck body join but now we see the improvement before we attack the string height with the bridge saddles.


Wow, what an improvement!

Now here's some things to consider before pulling things apart;

Do you have enough adjustment on your pickups to raise them to their sweetspot after you've shimmed?

Grease the neck screws with candle wax to help them tighten easily, make sure you don't cross thread them, don't over tighten them to the point where the metal neck plate starts to really bite into the laquer finish on the body.

Always support the loose neck in the neck pocket while you are bolting it back together.

Tighten all the screws evenly, meaning don't tighten them in one at a time as the neck can shift in the pocket.

If the neck has shifted and the strings seem over to one side of the fingerboard as you look at it, then slacken all the neck screws by a third/half a turn and then grip guitar between your legs, hold cutaway on the side the strings are 'leaning' towards then with your hand placed mid way on the neck and move/jerk in the opposite direction the strings are leaning, then re-tighten the screws

Hope this helps

[jazzbow]

Originally Posted by mattymel

the picture above is THE biggest shim i have ever seen.

I've used an old credit card once, now that was really thick! One nasty little guitar needed 3mm cut off the pocket to 'lower' the strings, but that was an exception.

[SamBooka]

I shim.. if the shim is too thick AND too narrow the neck tends to shift in the pocket...

I wouldnt trim the neck or the pocket to get the neck angle right except for the fun of it.. (and to me that isnt fun so I havent tried it)

on 60s style Jazzmasters (or at least my 97 CIJ ) it just made sense to shim to get a better break angle on the bridge. When I put 13s on there the point became mooo..

[PTChristopher]

Looks good J'Bow.

>>> Grease the neck screws with candle wax

The one downside of this that I have run into is when the maple gets stripped (by some haggis-munching, caber-tosser no doubt) then it is harder to glue in some stock to make the fix.

I had a stripped hole once that seemed to have soap in it - so I had to drill it out to a fairly large diameter, then make a maple plug. It worked fine, but I guess it is a potential downside of wax on the screws.

Chris

[PTChristopher]

I've never trimmed a pocket - but not because it would not work just fine.

I have glued a full, pocket-size maple piece to the neck and then carved it into a full shim.

But as mentioned, basic shims really do work. In my opinion.

Chris

[RuffRider]

You could also just get some shorter height adjustment screws - from:
AllParts.com

STEWMAC.COM : Guitar Parts

Wdmusic.com

[jazzbow]

Originally Posted by PTChristopher

Looks good J'Bow.

>>> Grease the neck screws with candle wax

The one downside of this that I have run into is when the maple gets stripped (by some haggis-munching, caber-tosser no doubt) then it is harder to glue in some stock to make the fix.

I had a stripped hole once that seemed to have soap in it - so I had to drill it out to a fairly large diameter, then make a maple plug. It worked fine, but I guess it is a potential downside of wax on the screws.

Chris

Hey Mr C.

Have you seen these bolt thingys?


That's well impressive! Keeping it all square looks like a big challenge.

[pingu]

The higher end F****rs should have these on

Yeah they're real F*****rs aren't they ? ;0)

[starjag]

Originally Posted by RuffRider

You could also just get some shorter height adjustment screws - from:
AllParts.com

STEWMAC.COM : Guitar Parts

Wdmusic.com

For sure! This is the non-invasible way to do it. However, some guitars do benefit with a shim.

[Help!I'maRock!]

seriously. if you ever come to NYC, i'm putting you to work.

[PTChristopher]

>>> Hey Mr C.
>>> Have you seen these bolt thingys?

Hiya 'Bow,

Not those exact ones; I did not know that Stewmac was selling them. I have used a very similar insert, but made of brass. The brass ones I've used have a coarse thread on the outside and the machine thread on the inside, much like the Stewmac ones seem to have.

The brass inserts need to have the coarse thread holes tapped though. The maple is too hard to just plow on in with the brass. I made a tap many years ago (absolutely no idea where it is now) - but it is possible that there are lag screws (no idea what the UK word might be) with a similar thread that can be easily adapted into a tap. It's funny how often that sort of coincidence happens .

I have seen inserts with a very aggressive outer thread presumably to make them self-tapping into the wood. Maybe the Stewmac inserts have this? - I do not see them on the website.

I guess the whole thing is a good idea, but I'd want to put thread locker on the lower screws. In dry weather the wood can shrink and take the tension off the lower screws. Not a big deal, but a consequence of machine threads.

Chris (NiAg)

[jazzbow]

Originally Posted by PTChristopher

I guess the whole thing is a good idea, but I'd want to put thread locker on the lower screws. In dry weather the wood can shrink and take the tension off the lower screws. Not a big deal, but a consequence of machine threads.

Chris (NiAg)

I found those on the stewmac facebook page just recently, the inserts were epoxy'd in,

I was thinking, do you think it would be a good idea to get some sticky threads on set ups etc. for the gizmo part of the forum? Y'know, answers to those 'How do I' threads.

By the way, I love your build thread, it's good to have you back Mr Nickel-Silver

[Richard-H]

I cornered myself into a similar situation with my strat. I replaced the neck with a Carvin neck, which I mistakenly assumed was the same height as a standard Fender Strat neck. It's not, it's thinner.

What made the situation near impossible is that I both glued and bolted the neck. This improved the sound of the guitar tremendously - no regrets there.

Except for the fact that the bridge saddles had to be lowered to the very bottom - the screws stuck out and I was in the same position as in the OP.

What I did was to buy a dremel and the dremel plunge-router attachment. I built a Jig to hold the guitar still and to give me perfectly square edges to guide the plunge-router. (Note - I also had to buy a couple of steel rods from Home Depot to extend the reach of the Plunge-Router).

I then routed out about a 3/8 inch area under the bridge - sinking the bridge into the guitar.

I the end, I'm very happy with how it came out. The only issue is that the tremolo bar hits the tone knob - but it can be pulled over it easily.

I know this is a lot more complicated then a simple shim, but having a tight (if not glued) connection between the neck and the body is critical to the resonance of the gutar. (and yes I would strongly recommend gluing the neck - you'll like it!)

[PTChristopher]

[Jazzbow]>>> the inserts were epoxy'd in

Oh yeah, I understand.

In case we are confused, I meant that I would use thread lock on the machine threads on the lower screws.

Hey, PM sometime to say an offline hello.

[PTChristopher]

[Richard H] >>> having a tight (if not glued) connection between the neck and the body is critical to the resonance of the gutar.

100% agreed, but I think there are ways to make this happen without gluing the neck in.

I guess "post hoc ergo propter hoc" might be the expression for the significant reported improvements consequent, but maybe not really due, to gluing.

A good fit between the neck and the body can be done in many ways while keeping the benefits of the original design of the guitar.

All in one person's opinion.

Chris