Strings and intonation question

[Alex79]

My G-string is a little sharp when fretted at 12th fret, I comparison to the harmonic. I can't move the saddler back any further, unfortunately, it is already all the way at the back. It is not a huge problem, but it still bothers me.

This particular G-string is a .018 string and it is tuned down one step to F.

I believe a different string gauge would help with it, but I'm unsure if I need to go up or down. Would a .017 or .019 help with the problem, i.e. do I need to increase or decrease the gauge to help with the problem?

Any advice is greatly appreciated. I need to buy new strings soon (as my stocks are low) and I usually buy them bulk, so I really don't want to experiment too much.

 

[bostjan]

Sometimes a fresh string will (mysteriously) solve intonation problems, but, odds are good that you're already pushing close to the edge of what your saddles can handle. Often, it is possible to replace a saddle with a shorter one so that you can back the intonation off even more. What kind of bridge is it?

There might also be the option of switching to a wound 3rd, but it makes the string feel quite different. Some (maybe most) people prefer it.

 

[JustinRhoads1980]

what is the scale length of the guitar?

 

[elkoki]

Have you tried lowering the G string saddle a little to see if that helps?

 

[Alex79]

It's a TOM bridge on a Les Paul and there's no adjustment possible. It looks like a normal black Nashville TOM and I can't even take the saddle out and reverse it. I've put a fresh string of the same gauge on. It's audible only on chords above the 12th fret (which you really never play), leads are fine, but it still drives me insane because I have a very sensitive ear when it comes to things not being in tune.... :-(

Because it is a small difference I think that a .017 or .019 string would already solve the problem, I just don't know which way to go.

 

[spudmunkey]

Try flipping the saddle around backwards. You MIGHT break a string sooner, but I had a similar intonation issue on my GLP and this solved it.

 

[elkoki]

Is the neck relief set well ? How's the action ? Is the truss rod too tight ..? If it's too tight ( or even if it isn't ) you can probably get away with loosening it slightly and lower your whole bridge just a little and that might help . Or if you don't want to do that just buy 2 single g strings and try and see which works.

 

[ixlramp]

My G-string is a little sharp when fretted at 12th fret, I comparison to the harmonic.

That's a bad way to intonate a guitar which is unfortunately commonly recommended. Use a tuner and observe the pitches of the open note and every commonly-player fretted note.

I believe a different string gauge would help with it, but I'm unsure if I need to go up or down. Would a .017 or .019 help with the problem, i.e. do I need to increase or decrease the gauge to help with the problem?

A .018 plain steel will be a very stiff string, a thinner gauge will help intonation, but also tone and harmonicity. I can't stand anything larger than .016.
Otherwise, replace it with a .019 or .020 roundwound, which will have similar tension but will be much more flexible and have a much better tone.

 

[Alex79]

That's a bad way to intonate a guitar which is unfortunately commonly recommended. Use a tuner and observe the pitches of the open note and every commonly-player fretted note.

A .018 plain steel will be a very stiff string, a thinner gauge will help intonation, but also tone and harmonicity. I can't stand anything larger than .016.
Otherwise, replace it with a .019 or .020 roundwound, which will have similar tension but will be much more flexible and have a much better tone.

Well I do this on my baritone and use a .020 wound string. The .018 still sounds ok on this particular guitar, but it might be the pickups.