Advice re: shimming

Kelly Coyle · #1 01-15-2009, 11:56 PM

I have to shim my Warr's neck. I think I get it (I talked to Mark Warr quite a bit yesterday), and it seems pretty simple: remove neck, insert very thin shim, replace neck, check it out, adjust if necessary. I'm still nervous though.

Is there anything I need to be wary of here? Or is it really that simple?

bassman275 · #2 01-16-2009, 12:07 AM

Make sure its at the back of the neck pocket so,it tilts the neck.

JustDavid · #3 01-17-2009, 06:42 AM

That's about it.

Bridge side of the neck pocket, & size the shim for nearly the whole width. I use part of a business card.

LanEvo · #4 01-17-2009, 07:00 AM

Keep in mind that when it comes to shimming a neck, a little goes a VERY long way. It's highly unusual to need a shim thicker than a standard business card.

Some folks will swear up and down that only a wood veneer will do the trick. But good luck finding a strip of wood veneer thin enough to do the job!

I've shimmed a couple of bass necks by cutting a standard business card into 3 strips (like a French or German flag). Usually, one of those strips at the very bottom of the neck joint is all you'll need. Once, I needed to stack two strips on top of each other...but that neck was VERY wonky to start with.

There's nothing to it. Expect to remove the neck once or twice to fine-tune things before you get it right. So, make sure you don't over-tighten the neck bolts! You wouldn't want to strip them

Sundogue · #5 01-17-2009, 07:00 AM

Shimming is all about adjusting the tilt of the neck in relation to the body.

Shim at the back of the neck pocket, but only if you want the angle that way (headstock lower than the body, from what it was). You have to shim towards the headstock end of the neck pocket if you want to raise the angle of the headstock (which I've found to be the more common one I've had to do).

Instead of using paper or cardboard, you could try using layers of drywall tape (the open, cross-weave thread kind...not the paper stuff) as it will have more "bite" and grabbing ability against the wood of the neck,and it has some light adhesive on it. By layering it (and using less the farther you get away from the highest point of the shim) and making the shim have a gradual incline along the length of the neck pocket, you will minimize the amount of empty space between the body and the neck. Too often I've taken necks off to find a piece of cardboard in there, and a huge gap between that shim and the rest of the neck pocket. The less empty space you have, the less negative impact it will have on the sound.

And yes, expect to do some trial and error adjustments. But it isn't hard to do at all. Biggest thing (as was already mentioned) is to make sure you tighten down the neck bolts good, but not so far as to strip the holes out. Oh...and when screwing it back on keep checking that the neck is firmly in place against the body. Sometimes the screws can seem to be tight, but there may still be a space in there that shouldn't be.

There was a good article on shimming a neck pocket in Bass Player mag a while back. Can't remember which issue it was.

cb56 · #6 01-17-2009, 07:06 AM

I followed the advice on this page.
http://garywillis.com/pages/archives...ask_jan00.html
It's been a year and no problems.

JustDavid · #7 01-17-2009, 07:37 AM

Good stuff, but I don't know about angling the shim. I'd have it paralleling the nut & bridge.

cb56 · #8 01-17-2009, 07:38 AM

Quote:

Originally Posted by JustDavid

Good stuff, but I don't know about angling the shim. I'd have it paralleling the nut & bridge.

Right. I agree. I think that pic has to do more with the angled Ibanez neck pocket.

Anesthesia · #9 01-17-2009, 07:39 AM

you can buy metal shim sheets in a can.

guess what its called.

thats right shim in a can. it comes in different thicknesses and different metals.

Kelly Coyle · #10 01-17-2009, 07:45 AM

I'm going to try it this afternoon.

Thangfish · #11 01-17-2009, 08:05 AM

Quote:

Originally Posted by cb56

I followed the advice on this page.
http://garywillis.com/pages/archives...ask_jan00.html
It's been a year and no problems.

Just take his instructions with a grain of salt.

Notice the picture shows the shim at the bottom of the pocket.
Notice the text says that "you've effectively lowered the strings..."

Fairly obvious mistake, but I can see this being confusing to someone unsure about the procedure.

JustDavid · #12 01-17-2009, 08:23 AM

The shim is angled. It doesn't have to be.

Sundogue · #13 01-17-2009, 08:25 AM

Quote:

Originally Posted by Thangfish

Just take his instructions with a grain of salt.

Notice the picture shows the shim at the bottom of the pocket.
Notice the text says that "you've effectively lowered the strings..."

Fairly obvious mistake, but I can see this being confusing to someone unsure about the procedure.

If given that the bridge saddle height has not changed, yes if you put the shim at the bottom of the neck pocket (bridge end), then you have raised the heel of the neck and lowered the headstock relative to the body, which would, in effect, lower the string height.

Putting the shim at the headstock end of the neck pocket would raise the strings (something I've had to do on a number of old basses).

JustDavid · #14 01-17-2009, 08:26 AM

Gary's got some good stuff. Not all; his PC spacers after the bridge (non-vibrating portion of string) for increasing string tension is a worse transgression.

This one isn't nearly so bad. It's going to need a setup after this anyway.

**DougD** · #15 01-17-2009, 09:24 AM

Just don't use an electric screwdriver. You could strip the wood (unless there are screw inserts)

Kelly Coyle · #16 01-17-2009, 12:35 PM

I did it. It seems to have worked. I need to do the other set up things now (I just dialed some relief back into the neck -- I had it absolutely flat trying to get the strings down), but the strings definitely came down nicely, and the neck seated right back into the pocket with nary a wobble.

Thanks again.

Relic · #17 01-17-2009, 12:54 PM

Quote:

Originally Posted by Sundogue

Putting the shim at the headstock end of the neck pocket would raise the strings (something I've had to do on a number of old basses).

I've had to do this on a number of older basses as well, works like a charm. Although I used parts of a cut up playing card. (an Ace of Spades of course

)

dave_bass5 · #18 01-19-2009, 03:16 PM

Hi guys.
Im pretty sure i need to shim my 2008 USA P5.
The strings seem to be quite hight at the body end but i still get a bit of fret buzz over the middle of the body as well. I like a low action but this doesn't feel low enough compared to my Duck Dunn.
Does this sound like it needs shimming? The neck is pretty flat already and there is room for adjustment in the saddles so its not bottoming out although the low B is almost maxed out.

Im confident enough to do it, i just cant work out if its needed.

Sundogue · #19 01-20-2009, 05:11 AM

Quote:

Originally Posted by dave_bass5

Hi guys.
Im pretty sure i need to shim my 2008 USA P5.
The strings seem to be quite hight at the body end but i still get a bit of fret buzz over the middle of the body as well. I like a low action but this doesn't feel low enough compared to my Duck Dunn.
Does this sound like it needs shimming? The neck is pretty flat already and there is room for adjustment in the saddles so its not bottoming out although the low B is almost maxed out.

Im confident enough to do it, i just cant work out if its needed.

If the neck relief is where it should be (and that is something that has very little to do with string height, though of course string height is affected by it), and you still can't get the strings low enough by lowering the bridge saddles, then yes you need to shim it.

Shim it at the bottom of the neck pocket to bring the strings closer. Then check your relief (though you could check your relief before shimming too). Remember that neck relief is about how much room there is between the bottom of the string and the top of the frets along the neck itself and not along the entire length of the string from nut to bridge. Adjust the relief (via truss rod) to give the strings room to vibrate without buzz along the middle of the neck. Bridge adjustments have no effect on that (except when the saddles are way too low but that affects the end of the neck too). Never adjust the neck relief to lower strings (unless it's severely bowed). It all has to work together.

The last thing is adjusting the string height on the bridge.

dave_bass5 · #20 01-20-2009, 07:56 AM

Thanks Sundogue.

My problem is i cant get the action low enough without fret buzz. There is still plenty of adjustment left in the saddles (other than the B string) but they seem to be as low as i can go without the higher notes choking.
Im now thinking its me and my bad technique rather than anything else. I tend to pluck quite hard with a pick and maybe that, combined with me more used to 4 string Jazz necks could be the problem.
Its just that i feel the action is a bit high at the body end but fine at the neck end.

Im not sure what way to adjust the truss rod. Am i right that more relief will give me less buzz in the middle and upper part of the neck? Maybe i need to do that.

Also, and i know this will sound silly, but I've read the spec's Fender suggest as a starting point for action but im assuming i should go by the E and not low B for the low side. Is this right?

Cheers.