What Exactly Is Neck Shimming?

JeffWiredBeck24 · #1 01-03-2008, 11:46 PM

For some reason whenever I search on this site my browser "quits unexpectedly"; sorry if this thread has been done.

Anyway, I lowered my bridge (Lo-Pro) as far as it will go and I'm still not happy with my action. I'd like it lower, and I've seen other threads where someone says "you should shim your neck". Could someone explain exactly what this is, and how it can lower action?

Thanks.

**jaxadam** · #2 01-03-2008, 11:51 PM

Well, shimming the neck is not going to "lower" your action, but it's going to change the angle that you neck "acts" on the body, pickups, bridge, etc.

You might have to actually raise your bridge a hair to compensate for this new adjustment.

reguv760 · #3 01-04-2008, 01:39 AM

like jax said, it's going to change how the neck is angled with the body. I made a quick visualization how it works based from my experience dealing with this subject.

The image is not to scale and is presumed the neck never had a shim and IS dead straight and all else (trem angle, bridge height, etc) is setup to near-perfection.
You'll notice the difference of angle's where the shim is placed... The black line represents a piece of paper with the thickness of a business card and the red arrow represents the trussrod adjustment necessary to make the neck straight again.
as jax suggested, you'll either have to raise or lower the bridge height depending how and if you change the angle...
lowering the bridge doesn't necessarily constitute low-action although it is part of the equation. It does affect how "easier" it is to play the guitar dependent on the strings, tuning, fretwire, and eventually, proper setup. Plus hitting rock bottom on the bridge height hinders trem-pullups

The Non-AANJ Ibby's I have always had a shim similar to the 2nd pic... if your guitar already has one, add a shim with the thickness of a folded business card.

Reg

JeffWiredBeck24 · #4 01-04-2008, 02:55 AM

^Thanks a lot guys. Very detailed.

IbanezFreak777 · #5 01-04-2008, 06:19 AM

Did my Ibanez RG550 come with a shim already in the neck. Because I have pulled apart my guitar a few times, and don't remember if it had one or not ???

millzy · #6 01-04-2008, 09:54 AM

holy **** ive got the exact same problem, my bridge is far to low and the action not where it should be

, i asked rich and he said about shiming the neck so im gonna do it soon, glad this thread was here

Axewielder · #7 01-04-2008, 11:53 AM

Is it best to make shims from scratch, or are there drop-in shims you can buy?

Jaden · #8 01-04-2008, 12:08 PM

Quote:

Originally Posted by Axewielder

Is it best to make shims from scratch, or are there drop-in shims you can buy?

you can cut up business cards, string packets

or fold up cooking foil - anything that works - no need to buy anything.

reguv760 · #9 01-04-2008, 12:16 PM

Quote:

Did my Ibanez RG550 come with a shim already in the neck. Because I have pulled apart my guitar a few times, and don't remember if it had one or not ???

If there is, it's probably stuck in the neck pocket. Depending how old your 550 is (unless it's a 20th), the paper shim ages to a certain yellow :P

Reg

millzy · #10 01-04-2008, 12:34 PM

so if i use a piece of card , (not the thick stuff, but really light), i should just fold it once and put it where exactly on the neck plate, granted that im on about the 2nd picture in the diagram?

Dee · #11 01-04-2008, 01:56 PM

You may not need to fold it. Try not folding it and see how it goes. Even a thin shim can have a big effect. If the neck needs to be at more of an angle or you want to raise the bridge out of the body a little more, try a thicker shim. It's just a matter of experimenting to get it to where you want it, there are no hard and fast rules. The only thing I dislike about shims is you're decreasing the contact of wood on wood in this area. Otherwise they can be very useful for fine-tuning the feel, action, and playability.

I really need to shim my RG 20th neck, the bridge sits too low in the body and this affects my picking hand, though I hate using a shim.

millzy · #12 01-04-2008, 06:39 PM

why do you hate using a shim Dee?
i recently just did it with a 4 way fold kept really tight with double-sided tape

reguv760 · #13 01-05-2008, 02:47 AM

Quote:

i recently just did it with a 4 way fold kept really tight with double-sided tape

might be too thick considering the double-sided tape adds a few micrometers... there's enough pressure to really "squeeze" that paper once the screws tight.
as long it works for your guitar i guess.

Reg

millzy · #14 01-05-2008, 10:47 AM

ALRIGHT LADS, I SHIMED IT LAST NIGHT! COUGH WITH A 5 FOLD AND IT WAS DISATRIOUS...IT WAS A TRIAL AND IMPROVMENT PROCESS AND WITH 3 FOLDS THE NECK WAS ANGLED IN SUCHA WAY THAT ANYTHING PAST THE 5THE FRET WAS A FLUBBED NOTE....
2 FOLDS IS THE WAY TO GO!! I FINALLY PUT A 2 FOLDER IN AND IT IS BEAUTY...PERFECT ACTION PRETTY MUCH AND MY TREM IS REASONABLY HIGH INSTEAD OF BEING RIGHT THE WAY CLUNKED INTO THE BODY!!

sorry for the font, i thought it was nesseary as this wasa big deal

JeffWiredBeck24 · #15 07-21-2008, 03:12 AM

Man, I completely forgot about this thread. I never got around to seeing if my guitar has a shim or not, but I've been having some problems with feel and playability and Dee said in an above post that a shim can be used to fix problems in these fields. My neck feels a bit, stiff right now. The action isn't ridiculously low but I'm still getting A LOT of buzz on the bass strings. Bending below the seventh fret feels stiff and rough and it just doesn't feel as nice as it used to.

Can anybody tell me what, where, how, and in what direction I should put a shim? Size of the shim? Business card, string packs, etc.?

Thanks a lot.