Neck shims and zero neck relief

[g1hsg]

Hi all. I'm currently trying to set up an old Aria Pro II for my daughter. I stripped it down to refinish it some 3 months ago and then all manner of annoyances (work etc) got in the way. Refinished it in black last week & it looks great. However upon reassembly the neck seems to have developed several problems. The action was always a little on the high side but now its laughable even with the saddles adjusted so low they touch the bridge. With all the tension off the truss rod the neck is dead straight. The neck & body were stored flat, fully supported and at room temperature. The neck seems stable enough and has remained in tune since reassembly for a week. I have considered a full neck shim to bring the neck up relative to the bridge, what material do you suggest ? As regards the neck relief my only thoughts would be to restring with heavier gauge/higher tension (currently 45-105). Its a later model (Korean manufacture) and whilst its only worth buttons it looks (so I'm told by my daughter) 'well sick' and hasn't been out of her hands for the last week - in a way that her Jazz never was.

[Kiwi]

Could you clarify what the problem you're dealing with here? Is the action too high? The neck too bowed? Or the neck at the wrong angle to the body?

[bnt]

In my case (the Tune) the neck was at the right angle, joint was flush - but once I adjusted the neck action correctly, the bridge could still not be adjusted low enough. As a temporary fix I added steps of gaffa tape to the neck slot, changing the neck angle back a bit, and I can now get a decent action. As a permanent solution I'd take it to a pro, ask for a solid shim or a lower (or recessed?) bridge.

[g1hsg]

[quote name='Crazykiwi' post='304209' date='Oct 10 2008, 10:41 PM']Could you clarify what the problem you're dealing with here? Is the action too high? The neck too bowed? Or the neck at the wrong angle to the body?[/quote]

Sorry. The body/neck angle is fine. There are two problems. I cannot generate sufficient neck relief. The truss rod has no tension on it - ive even removed the nut completely at one stage , yet the neck remains impossibly close to dead straight. Secondly the action is too high, the neck needs to be brought up relative to the bridge ( or as has been suggested lower down in the thread the bridge brought down by routing )

[budget bassist]

Have you tried adjusting the truss rod? I'm not being condescending but you didn't mention anything about it and it would be silly not to check.

[Thunderhead]

DO NOT rout the body or do anything drastic like that!!! It's totally unnecessary.

You simply need to add a shim at the body end of the neck pocket. There's no need to raise the entire neck either, in fact it's far less effective - the relative lengths of the neck pocket and the neck itself mean that a very small movement at the end of the heel will make a much larger difference at the headstock, and create a small back angle on the neck which will drastically lower the string height over the end of the fingerboard. This is absolutely standard practice with bolt-on necks where the angle isn't quite perfect.

You also don't need fancy materials, stiff cardboard is ideal - Fender used this or thin fibreboard from the 1950s onward, and still do on instruments without a neck-tilt mechanism. Simply cut a piece which fits into about the last quarter of the neck pocket, and preferably covering the two end screw holes so the screws will push through it rather than missing it, as this helps avoid causing an upturn at the very end of the neck. I would use a piece of something like a cornflake packet to start with, and if that isn't enough just find something a bit thicker and of the same type - or you can use a couple of pieces on top of each other. (That's exactly what I use, and I do this sort of thing professionally.)

Don't be afraid of it 'killing the tone' or any other popular myth. In fact, there's good evidence that these traditional shims actually sound better than the so-called "improved" method of making a tapered wood wedge which you will sometimes hear recommended. Think about it... many vintage Fenders have cheap shims from the factory and they're some of the best-sounding instruments ever made. If you really can't live with 'cardboard in your bass', a small piece of wood veneer is a good alternative, and you could glue it to the floor of the neck pocket if you want to make a really good job (after you've found the right thickness of course). Gaffer tape is not the right material though!


If the neck is still too straight, you'll either need to give it more time to settle down (if it's been left for months with no strings you can expect it to take about the same amount of time) or use a slightly heavier string gauge, at least until it does. 'Dead straight' is not a problem though - provided that it is, and not back-bowed.

Edited October 11, 2008 by Thunderhead

[Kiwi]

I'd agree that a dead straight neck is ok, however if the frets aren't completely level then you'll end up getting fret buzz. What concerns me is the lack of an effective truss rod. If the neck is dead straight, that would suggest its resisting the string tension quite effectively. So the question in my mind is whether the truss rod has been over-tightened? The neck shim is a good idea too, the neck angle could be adjusted to bring the strings closer to the neck at the heel end. I personally love the microtilt feature on my stingray but once set its no problem to forget.

[griffonite]

[quote name='Crazykiwi' post='304321' date='Oct 11 2008, 09:12 AM']I'd agree that a dead straight neck is ok, however if the frets aren't completely level then you'll end up getting fret buzz. What concerns me is the lack of an effective truss rod. If the neck is dead straight, that would suggest its resisting the string tension quite effectively. So the question in my mind is whether the truss rod has been over-tightened? The neck shim is a good idea too, the neck angle could be adjusted to bring the strings closer to the neck at the heel end. I personally love the microtilt feature on my stingray but once set its no problem to forget.[/quote]

I recently purchased a G and L 2000 with the neck tilt feature but have never used one before. Can anyone explain how it works. What effect do certain adjustments have. I have no problem with adjusting truss rods and understand how certain adjustments affect the action but not sure how the neck tilt works in the truss, bridge height equation.

[sgt-pluck]

For what it's worth and to second everything Thunderhead says: pretty much all of the second hand basses I've bought have either had body-end neck shims already in place, or have needed one putting in to allow for the aftermarket bridges fitted which never seem to adjust as low as the stock bridges IM(limited)E. I did once try shimming an entire neck pocket but I got no-where with it. The only thing I would say is that it can take a bit of experimentation to find the right thickness for the shim - a few thou makes a big difference!

Pluck

Edited November 9, 2008 by sgt-pluck

[The Burpster]

I think we all covered it nicely in this thread.....


Read and enjoy.......

[url="http://basschat.co.uk/index.php?showtopic=18034&hl=shim&st=20"]http://basschat.co.uk/index.php?showtopic=...=shim&st=20[/url]

[Kiwi]

[quote name='griffonite' post='324726' date='Nov 8 2008, 11:16 AM']I recently purchased a G and L 2000 with the neck tilt feature but have never used one before. Can anyone explain how it works. What effect do certain adjustments have. I have no problem with adjusting truss rods and understand how certain adjustments affect the action but not sure how the neck tilt works in the truss, bridge height equation.[/quote]
The neck tilt affects how parallel the neck is to the strings. Too little tilt and you get low action at the nut and high action at the 21st fret. To much tilt and you won't be able to play anything in the lower registers because the strings will be making full contact with the upper frets. Ideally you need to straighten the nack as much as possible with the truss rod and then make sure the angle is shimmed so that the neck is perfectly parallel to the strings. Some of the effects of incorrect tilt for open strings can be mitigated by raising or lowering the action but the playability won't be inproved with any fretted notes.

The micro tilt feature on Leo Fender designed instruments allows you to alter the neck angle using an allen key through the neck plate on the back of the instrument without having to completely remove the neck. The shimming instead is accomplished by a small hex screw in the neck pocket. Basically, you slacked the string tension, loosen the neck bolts and adjust the screw and then check by tightening everything up again. Sometimes I've been able to make minor adjustments of tilt in the direction of the string tension by loosening the neck bolts only. Very handy feaure but the neck pockets do benefit from being nice and tight around the sides of the heel for there to be good acoustic coupling between the neck and the body. There are some Fenders with sloppy neck pocket routing, where the neck shifts all over the place because the pocket is too big for the heel.

See also this guide:

[url="http://www.fretnotguitarrepair.com/El_Guitar_Neck_Angle.htm"]http://www.fretnotguitarrepair.com/El_Guitar_Neck_Angle.htm[/url]