Shimming Electric Bolt-On Necks?

[David Edward Helmer]

At work there are a good amount of Electric guitars and basses that have the bridge saddles jammed to the bottom with high action. There is some plastic shim stock here. Can I just use this plastic to shim these? Considering what I have at my disposal here, this seems like the only option. I did one on a mediocre bass and it worked. Acceptable? How will this affect tone and sustain? I am more of an acoustic guy so, I am just wondering what you all think and feel about it.

Thanks!

[Greg Mirken]

Shimming is fine. I use maple veneer, but hard plastic is OK.

[Robbie Collins]

When I started playing guitar my friend's dad was a respected luthier.  He used playing cards to make laminated, tapered wedges for electric guitars. He'd glue a 1/4" piece onto a 1/2" piece and that on a 1" etc depending on how thick it needed to be.  I don't know if it makes a difference, but the new cards are plastic.  I would think that the paper ones would be more conformable. Tone? I have no idea.

[RETROROD]

I would think that wood shims would be preferable (tonally)...but have no real evidence that other materials would make a discernable difference! A "bolt on" IS what it IS! Snug 'em up and go...

Sort of reminds me of the hide glue rhetoric. A guitar's attributes are the result of many different things.

Sometimes we get lucky...!

Hope I'm not being 'snippy'...

[Eric Steven Johansen]

Doesn't sound "snippy" to me. LOL

[Gary Fried]

Well first make sure that the neck is straight if you haven't already. Shims are fine but beware that if they get too thick they will cause a rise in the heel and cause some choking in the upper frets. I've seen some guitars come from the factory with 1/16" plastic as shims. 

[David Edward Helmer]

Not being snippy at all. haha Snug em and go is exactly what I am doing. Wood shims would be preferable but I only have hard plastic here at the store. Robbie, the playing cards idea is a great one. Never thought of that but makes sense. Put it in the arsenal. Gary, I am not approaching 1/16", man that is a lot! The most I had to shim one is 1/32". If you made a nice smooth shim that transitioned well would that take care of choking? Thanks for the responses!!!!
 

[Robbie Collins]

I think Gary may be saying that if the wedge is too thick the neck will be overset.

[Jeff Highland]

Some folks believe that if you shim a neck at the bridge end of the pocket only, it can bend the neck in that area from the screws attempting to bring the neck into contact with the pocket,

I am not sure if I accept that, I have not seen it, but a stepped or tapered shim extending  to the head end screws would avoid that risk

[STGuitarworks]

I use wet/dry sandpaper in stepped layers. Shims can strongly encourage warpage unless they're even and gradual.

[Alexander López]

I have in my bench a Parker and an Ibanez Jem (Korean-made) and both came with cardboard shims. To improve the tone I buy these cheap aluminum erasing templates and cut them to size: http://tinyurl.com/bda2o87

I can stack them to get the angle I want, and they won't get compressed. Cardboard certainly works, but if you are concerned about tone, a metal shim is better than cardboard.

[Thomas James]

I use wood veneer shims and secure with a very light wood glue on the bottom after thickness and fitting. Wood on wood.

[Mark Wallace]

I tend to agree with what Jeff and Gary said. I usually try to make tapered wood shims that run the length of the neck pocket. Using a shim at the end of the neck pocket leaves a void space between the neck and the body. I have seen older bolt-on neck guitars develop a severe upward bow in this area due to the the force of the screws pulling the neck downward where it is no longer supported. I have noticed this more frequently on Fender guitars that utilized the Micro-tilt neck angle adjustment system. I can't speak to the sonic differences but, at least from a mechanical perspective, anything that detracts from the complete coupling of the neck/body mating surfaces might also have some negative effect on sustain.