Shimming even though a shim is already in place?

Epitaph04 · #1 11-07-2011, 07:55 PM

If I want to shim a bass (bridge saddles maxed out) but a shim is already in place, should I just add a shim on top of the shim that was already in place?

jmercer91 · #2 11-07-2011, 08:01 PM

That, or use a thicker shim... Has the truss rod been adjusted properly, and are you using an aftermarket bridge? Only asking cause MOST basses don't need that much of a shim if the bridge is stock.

Epitaph04 · #3 11-07-2011, 08:03 PM

Its a used Bongo 6 I got from here a few days ago. The bridge saddles are maxed out, and it almost feels like the truss rod on it is maxed out as well. I popped the neck open and a shim is already in place.

bassteban · #4 11-07-2011, 08:03 PM

AFTER making sure every other facet of your setup is good, consider this: Does the existing shim cover most of the neck pocket? Adding a card or two worth of thickness at the heel- more toward the bridge(but NOT at the other end)will slightly increase the neck angle*, as opposed to simply raising the entire neck.

*Doing the same at the more nut-ward(

)end of the pocket will slightly decrease the neck angle(Edit: Which is NOT what you want to do, just going by your description).

walterw · #5 11-07-2011, 09:15 PM

Quote:

Originally Posted by Epitaph04

Its a used Bongo 6 I got from here a few days ago. The bridge saddles are maxed out, and it almost feels like the truss rod on it is maxed out as well. I popped the neck open and a shim is already in place.

"maxed out"? what does that mean?

the saddles are cranked up as high as they can go? and there's a shim in the neck pocket at the body end?

if so, remove it. then, the saddles will be way too high, and you can drop them back down to a normal level again.

Warfender · #6 11-07-2011, 09:33 PM

Walter good question. I took it as the bridge is lowered as low as it will go and not lower enough.

Bassteban stated the purpose of shimming well. Thick card stock, non-raise number credit card style items work great, etc.

Epitaph04 · #7 11-07-2011, 10:20 PM

No, the bridge saddles are as low as they can go, yet the action isnt quite where i want it, especially on the low B and high C strings, where the action is quite high. I was going to shim the neck but i noticed it was already shimmed, and i remember reading somewhere around here a while ago that it was not good to shim an already shimmed bass or something like that.

So I'm just wondering if shimming it on top of the shim thats already there is okay or if itll blow up if I do or something.

96tbird · #8 11-07-2011, 10:29 PM

Go ahead.

walterw · #9 11-07-2011, 11:45 PM

OK, so the saddles are "buried", not "maxed".

where was the shim in the pocket? by the body end, or at the neck end?

walterw · #10 11-07-2011, 11:49 PM

in general, you shim what needs shimming; if there's one in the pocket and it's not enough, either replace it with a thicker one or stack another thin one on top of it, whatever it takes.

there's plenty of threads about "tapered" shims; if the primary shim "stack" is pretty tall, you can add a shorter shim in the middle of the pocket to fill that gap and add support. use a straightedge laid in the pocket to find the spot where the middle shim "makes contact", then glue it in place with a little spot of superglue.

Epitaph04 · #11 11-07-2011, 11:58 PM

It was shimmed closest to the neck pickup, so i guess that means it was shimmed right under the neck end, if I understood correctly.

walterw · #12 11-08-2011, 12:09 AM

so it was already shimmed at the body end (as opposed to the "neck" end) of the pocket, but the action was still too high, even with the saddles buried?

are you sure the neck was itself sufficiently straight? how low are the nut slots? music mans don't usually need a bunch of shimming to get low action.

Epitaph04 · #13 11-08-2011, 12:20 AM

I couldnt tell you how low the nut slots are...Im terrible at all this bass set up stuff. I tried to straighten the neck but it felt like the truss rod was already getting very tight so I didnt want to keep trying to turn it.

I'm definitely just taking this to a tech on wednesday to keep me from doing anything stupid.

Warfender · #14 11-09-2011, 02:14 PM

Quote:

Originally Posted by Epitaph04

I couldnt tell you how low the nut slots are...Im terrible at all this bass set up stuff. I tried to straighten the neck but it felt like the truss rod was already getting very tight so I didnt want to keep trying to turn it.

I'm definitely just taking this to a tech on wednesday to keep me from doing anything stupid.

Good call. Be careful and don't break anything. What brand bass and what brand bridge is on it? Can you show some pics? What is the relief at the eigth fret with the first fret and 12th frets pressed down? Should be about a credit card to business card gap.

Wondering if it had a bridge swap that is screwing it up.

john grey · #15 11-09-2011, 02:29 PM

Bring it to a shop and let someone who sets up guitars (i..e. basses) do this for you. it will be money well spent. You stated you had a Music Man Bongo 6 string, which must have cost a serious amount of money: a cost of a good dinner will be a bargain at this juncture.

georgestrings · #16 11-09-2011, 04:47 PM

Quote:

Originally Posted by john grey

Bring it to a shop and let someone who sets up guitars (i..e. basses) do this for you. it will be money well spent. You stated you had a Music Man Bongo 6 string, which must have cost a serious amount of money: a cost of a good dinner will be a bargain at this juncture.

This - the odds of a Bongo being that far out of whack without some serious "operator error" are pretty slim... Let someone who knows what they're doing take a crack at it, OP - before you screw up a fairly expensive bass...

- georgestrings