Neck Shim - best options

[tonyclaret]

Hi,

i have a Fender MIM 70’s re-issue with block inlays.

its got a Hipshot Bridge and it’s set at its lowest possible point before becoming redundant! 

The neck I’ve pretty muched maxed out on truss rod.

It plays and sounds great, however the action is not as low as some of my other jazzes.

So, cut to the chase.

I’m thinking a shim at butt of the neck would reduce the action. Looking up on the web, there seems to be a lot of opinion on what materials to use etc. Business cards, must be wood for resonance! Etc. I did find an article where the bass in question had what looked to be a Fender installed branded plastic shim.

Intrigued to hear peoples thoughts and advice. To be honest I was just going to whack half a business card in there. Are there any pre-made options available in the UK?

Cheers

Tony

 

[BassBunny]

I've used an old cut down Credit/Debit card in the past and it worked perfectly.

[Andytre]

I've use plastic cards, business cards, walnut veneer and cut down ice cream tub (basically whatever i could grab) all did a fine job. never heard the science of the acoustic resonance of ice cream tub though, maybe its the bets kept secret in shimming! 

[JohnDaBass]

Stewmac .com sell pre cut wooden neck shims at a range of angles from 0.5 to 2.0 degrees. 

Here

http://www.stewmac.com/SiteSearch/?search=neck shims for bass&facet=%7cBRAND%3aSTEWMAC

[BigRedX]

10 minutes ago, JohnDaBass said:

Stewmac .com sell pre cut wooden neck shims at a range of angles from 0.5 to 2.0 degrees. 

Here

http://www.stewmac.com/SiteSearch/?search=neck shims for bass&facet=%7cBRAND%3aSTEWMAC

For a company that is supposed to be a serious luthier suppliers Stewmac sometimes write some real nonsense!

Then again if they can sell someone an £8 (plus shipping etc from the US) part that whose function can be suitably duplicated with a a piece of card that can be obtained for free, then good luck to them. 

The values of the shims them sell: 0.25°, 0.5° and 1° may not sound a lot but a standard business card thickness filling half the neck pocket is usually more than enough to solve most neck angle problems, and is roughly the equivalent of the 0.25° shim. 

The argument for not leaving any bare wood "exposed" within the neck pocket makes little sense when one of the solutions they sell will still leave some wood exposed because 1) it is unlikely to be a completely snug fit in the pocket and 2) the holes for the screws are oversized. If you are really concerned about leaving bare wood open to the air within the pocket then seal any un-laquered surfaces on the pocket and neck heel before reassembling the neck joint.

[joescartwright]

I had some 0.5mm veneer hanging around, cut it to shape and sanded one end down to virtually nothing, took ten minutes and worked really well.

[Marc S]

I wouldn't have thought there would be a resonance problem, using thin card - at least by the time the neck bolts are done up tightly, it should all be solid...
If you really want to use wood, you could try a model shop. They sometimes sell really thin pieces of ply or balsa
Good model shops will also sell A4 sheets of plastic-card. You can get plastic-card in several different thicknesses, from very thin to mm's thick.
A thin one should suffice, and you can even glue / laminate several pieces together, if you needed to. It's easy to cut and shape, with a Stanley knife

[converse320]

This has got to be something with lots of scope for dramatically changing the way the whole bass resonates?  If the neck is supposed to be solidly in the pocket, and snug against the surface of the body, surely sticking bits of card/plastic/wood or whatever between two must be undesirable.  But I've never heard of anyone recutting the pocket, or neck, so why don't luthiers do this instead of shimming?  Curious really.

[BigRedX]

18 minutes ago, converse320 said:

This has got to be something with lots of scope for dramatically changing the way the whole bass resonates?  If the neck is supposed to be solidly in the pocket, and snug against the surface of the body, surely sticking bits of card/plastic/wood or whatever between two must be undesirable.  But I've never heard of anyone recutting the pocket, or neck, so why don't luthiers do this instead of shimming?  Curious really.

I doubt it.

I have shimmed the neck on my Squier Bass VI. Pretty much everyone does, as it's the only way to get the break angles over the bridge right. I put a cut-down business card in the back quarter of the neck pocket. Uncompressed this is about 0.5mm thick. Once all the neck screws have been tightened up it will less. Looking at the pocket from the side there is just enough room to slide in a piece of 80 gsm paper (roughly 0.01mm thick) 25mm wide into the gap. The same piece of paper folded in half to make it 0.02mm thick won't fit in the gap. The rest of the joint is a completely snug and gapless fit.

So from what I can see the is a hairline gap of less than 0.02mm in the middle third of the neck pocket . Either end where the neck is attached to the body by the screws it is a completely snug fit. In fact I would venture that since the card is likely to compress more than the wood of the body or the neck, there will be fuller contact between the two surfaces at the point where I have added the shim that there was before.

Most of the contact anyway will be from the end of the neck against the end of the pocket cause by the pull on the strings. In fact one of the tricks to get the best possible neck joint on a bolt-on neck is to slacken off the screws very slightly before re-stringing and then re-tighten them once the instrument has been strung and tuned to the correct pitch. This allows the tension in the strings to pull the neck as tightly as possible into the pocket.

[A.G.E.N.T.E.]

I've shimed a bass before with relative sucess. And i say relative because the shim let a litle, barely noticeble gap between the neck and the pocket. In result, playability got better but it lost some attack and sustain. Any bit of Wood or plastic that  not beeing in full contact Will have some side effects. Some might ear it some might not. 

[T-Bay]

In my target shooting days we always used photographic film for shims, it’s cheap, very very consistent thickness wise, waterproof and stable over a long time period, especially if changes of humidity are a possibility. I have a small stock of old plates from my PhD which I have saved for future shimming purposes. 

Edited December 8, 2017 by T-Bay
Typo

[Bassassin]

I've shimmed dozens of necks on guitars and basses and never noticed the slightest difference in tone, sustain, resonance etc from any of them.

Material-wise, whatever's to hand, don't agonise over it! Thin cardboard will actually compress a little so if the idea of a micrometric gap under the heel is one that sends you into cold sweats, then using this might help you cope...

Currently I favour thin, stiff plastic card - the sort used as dividers in document binders. I like this because you can stack it in stepped layers to achieve the height/angle you need.

[Paul S]

I've had a couple of basses that have formalised this and had a 'micro-tilt' arrangement - an adjustable thingy on the neck plate that raises or lowers the neck at that point.  One was a Fender Precision Lyte but I can't remember what the other one was.  The Lyte sustained for ages.

[Dan Dare]

It sounds as if you need to raise the whole neck away from the body a little, rather than adding a shim at one end to increase the break angle, so a shim covering the entire neck pocket surface looks the way to go. Fwiw, I don't buy the arguments about decreasing resonance by introducing a tiny gap, etc. However, covering the entire neck pocket surface won't result in any gap if you do it neatly ( a piece of veneer - you can experiment with thickness - should do the trick).

[tonyclaret]

4 hours ago, Dan Dare said:

It sounds as if you need to raise the whole neck away from the body a little, rather than adding a shim at one end to increase the break angle, so a shim covering the entire neck pocket surface looks the way to go. Fwiw, I don't buy the arguments about decreasing resonance by introducing a tiny gap, etc. However, covering the entire neck pocket surface won't result in any gap if you do it neatly ( a piece of veneer - you can experiment with thickness - should do the trick).

I wasn’t thinking that myself, perhaps the whole neck needs rising. Veneer, do you mean this kind of thing?

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F253249344214

[Dan Dare]

11 minutes ago, tonyclaret said:

I wasn’t thinking that myself, perhaps the whole neck needs rising. Veneer, do you mean this kind of thing?

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F253249344214

Yes. I think raising the whole neck slightly would be the way to go. As you like the way it plays, it sounds as if the neck angle is good and you just want to lower the action overall. Shimming one end of the neck will alter its angle by canting it back, so you'll lower the action at the top end, but you'll have to adjust the nut to take care of the low end. I'd experiment with varying thicknesses of card (don't glue them in place so you can change them) and then get a piece of veneer in the thickness that works best.

[Manton Customs]

35 minutes ago, Dan Dare said:

Yes. I think raising the whole neck slightly would be the way to go. As you like the way it plays, it sounds as if the neck angle is good and you just want to lower the action overall. Shimming one end of the neck will alter its angle by canting it back, so you'll lower the action at the top end, but you'll have to adjust the nut to take care of the low end. I'd experiment with varying thicknesses of card (don't glue them in place so you can change them) and then get a piece of veneer in the thickness that works best.

Adding a shim does not require anything to be done to the nut, that's dictated by the height of the first fret and to a lesser extent the relief.

An angled shim is usually preferred as it's more invisible and you can get away with much less material creating a (very small) angle, rather than just lifting the neck. But both work. Usually the amount of angle required is so small you can't see or feel any difference.

I like veneer best also, card works, but it compresses and could possibly deteriorate over time. I've never noticed any sonic difference between a shimmed neck and one that hasn't been, but personally still prefer milling the pocket to the correct depth/angle. I wouldn't ever ship one of my instruments with a shim, it just seems kind of tacky on a new instrument. But it's a perfectly acceptable repair method.

And before anyone mentions it....no shims do not cause ski jumps, or twists!  

[Delberthot]

I use worktop edging as it's made of wood veneer and I happen to have loads left over from when I did my kitchen

[NancyJohnson]

On 08/12/2017 at 15:41, converse320 said:

This has got to be something with lots of scope for dramatically changing the way the whole bass resonates? 

 

With all due respect, this type of comment kills me.

[EssentialTension]

On 08/12/2017 at 16:41, converse320 said:

This has got to be something with lots of scope for dramatically changing the way the whole bass resonates?  If the neck is supposed to be solidly in the pocket, and snug against the surface of the body, surely sticking bits of card/plastic/wood or whatever between two must be undesirable.  But I've never heard of anyone recutting the pocket, or neck, so why don't luthiers do this instead of shimming?  Curious really.

The purpose of shimming a bolt-on neck is to get an appropriate neck angle as cheaply, easily and quickly as possible. It's an early Fender production technique. Recutting pockets was not a financially sensible production technique for Fender's way of doing things. The micro-tilt neck of the 1970s was an attempt to re-engineer the idea of a shim.

In my experience, there is no dramatic change to the resonance of the whole bass, nor even an undramatic change.

[NancyJohnson]

1 hour ago, EssentialTension said:

The purpose of shimming a bolt-on neck is to get an appropriate neck angle as cheaply, easily and quickly as possible. It's an early Fender production technique. Recutting pockets was not a financially sensible production technique for Fender's way of doing things. The micro-tilt neck of the 1970s was an attempt to re-engineer the idea of a shim.

In my experience, there is no dramatic change to the resonance of the whole bass, nor even an undramatic change.

This.

Resonance?  Are you holding a note for ten or fifteen seconds and expecting the note not to deteriorate?  Nah. 

[converse320]

On 12/17/2017 at 08:37, NancyJohnson said:

With all due respect, this type of comment kills me.

Well, it was a question really.  It seems odd to me that shimming doesn't make any significant difference.  I'm not claiming it does make a difference, just trying to understand why it doesn't.   

[EssentialTension]

13 minutes ago, converse320 said:

Well, it was a question really.  It seems odd to me that shimming doesn't make any significant difference.  I'm not claiming it does make a difference, just trying to understand why it doesn't.   

Well, let's assume a shim might make some difference to resonance (or to tone more generally). But then ask another question.

What other factors will make a much greater difference than a shim, even if it made some difference? So many other factors are more relevant that a shim pales into relative insignificance. And I'd be very surprised if anyone in a blind test could accurately tell non-shimmed Fenders from shimmed Fenders or any other bolt-ons.

However, as BigRedX said above, one point of the shim is to get the neck angle correct for a good string break angle at the bridge. A good break angle at the bridge might well improve resonance but it's not because there is a shim as such; it's because the neck angle and break angle are improved and so the connection between strings and body is improved. In that case we might try to claim that correct shimming on some Fender style instruments will indirectly improve resonance.

Edited December 18, 2017 by EssentialTension
Addition

[Dan Dare]

On ‎17‎/‎12‎/‎2017 at 08:37, NancyJohnson said:

With all due respect, this type of comment kills me.

Me too. Some appear to think that pickups are microphones.

[converse320]

1 hour ago, Dan Dare said:

Me too. Some appear to think that pickups are microphones.

As I said above, I'm trying to understand why shimming makes no difference to sound, rather than claiming that it does make a difference.  I don't think guitar pickups are microphones, but I do think pickups are measuring small and complex patterns of vibrations in strings.  I would absolutely have expected that the way the neck joint is formed would make a difference to the way that strings vibrate.  To me, it's a bit puzzling that it doesn't.