How to set intonation and how to tune correctly

[Steelpriest]

Well, don´t laugh at me, but I discovered a fact. It took me over twenty years to discover it...

When you re-string your guitar and maybe clean it as well when the strings are all off, then put on new strings and bring it back to tune... in which position is the guitar? Most likely it lies flat on its back on the table?

When setting intonation I found out the following:
A guitar that lies flat on its back is in a position where the neck is bent back slightly by its own weight! Thus the note is a little bit sharp! When you bring the guitar back into a playing position this effect is neutralized and the everything you tuned is a little bit flat. (Well, I mean: you tune to pitch, but bringing the guitar back to its normal position will detune it slightly to flat) Well, everybody is obviously tuning in a playing position with the guitar around his neck and shoulders or the guitar might sit on his knee, so this is not a big problem... But I found this effect amazing! How much influence this has on setting intonation. You cannot set intonation precisely when a guitar lies on a table or a work bench... the neck bends back (in other words it is more straight), and thus settings you make are not accurate...

I spent the weekend controlling all my guitars thoroughly and found interesting discrepancies on some guitars concerning the intonation.

By the way: concerning the effect of a back bending neck when being placed flat on a work bench: bolt-ons were more affected, also were Flying V´s with set necks (these necks are very long compared to a Les Paul!), hardly or less affected where Les Pauls (they have a massive neck joint and a short overall neck length) and my neck-thru guitars.

Steele.

You now can all laugh at me! D'oh! Well, I hope I made it understandable in english as a non-native speaker.

[Jimboe]

Hey Steele, thanks for the info. I`ve never given any thought to where the guitar is positioned when changing string or setting intonation as I always do these things while my guitar is upright on the stand. I guess being disabled has it`s f****d-up advantages.

Jim

[Steelpriest]

Well, I think really upright in a stand without too much pressure from behind on the neck is fine.

[goldtopsnopp]

When I had my guitar for a setup they put on one holder against the neck and one on the body, so that the weight was spread on both the neck and body. Maybe that was the reason...

[guitarzan]

Good evening, Steel. Me personally, when I restring, I always leave the headstock over the edge of the table so the weight of the guitar doesn't rest on it. It lays flat on the table. I also use those fender guitar stands, so the neck isn't leaning against the stand. I'm kinda paranoid about the neck getting all out of whack, so I do all these things to minimize the risk. As far as intonation, I was told to play a harmonic at the 12th fret, and then fret the string in the same. If it's higher when fretted I think you're supposed to lengthen the string, and vice versa if it's lower. I hope I haven't completely confused you, but I think that's what my tech said to do. Lemme know if I'm right cuz I'm not positive about that. I've been playing since i was 8 (self taught) and am 45 now, and I learned about intonation about 6 months ago! Peace.

[CAFeathers]

I always use a fretted 12th. Sometimes intonating at the 12th fret leaves the first 3 or 4 frets out of intonation. At this point you would need to intonate at the 7th or 5th frets to get a balance.

[Steelpriest]

Well, intonation can never be 100% on any fret on the fretboard, you must always choose a compromise. The main topic was, that one should tune and intonate in a playing position and not tune or intonate a guitar that is flat on its back on a table. The neck actually bends back a bit pulled by its own weight. Try it. Tune a guitar on a table and bring it back to playing position, you will recognize all the notes are slightly flat. D'oh!

Steele.

[CAFeathers]

Steelpriest said:

Well, intonation can never be 100% on any fret on the fretboard, you must always choose a compromise. The main topic was, that one should tune and intonate in a playing position and not tune or intonate a guitar that is flat on its back on a table. The neck actually bends back a bit pulled by its own weight. Try it. Tune a guitar on a table and bring it back to playing position, you will recognize all the notes are slightly flat. D'oh!

Steele.

Very True, but sometimes it is off more than it should be on the lower frets.

I always intonate my guitars while holding them in playing position.

[mandough]

Steele wrote:
Well, don´t laugh at me, but I discovered a fact. It took me over twenty years to discover it...

Don't feel bad, bro. I did the same thing for years until I read the repair book I got for Christmas this year past. One other point I read in there is that if you rest your arm on the lower bout when you tune, it will pull the neck just enough to mess with it. I try to balance the guitar against my leg and torso amd only touch the tuners.
BTW, I wonder if it makes any difference if you use the 12th fret harmonic, or the open string when comparing to the 12th fret? It seems to me that the harmonic, being exactly half the distance will always be exactly in tune with the string, if not the 12th to bridge length. Ideas?

[guitarzan]

Mr. steel, I think you missed my point. When I lay the guitar on the table, I make sure the headstock's over the edge of the table. It doesn't touch it, and the guitar sets flat. I've never had a problem with any thing related to tuning or intonation (since I recently learned how to do it) by doing this. That's all I was saying. And with the squire cuz there's no angle to the headstock, it's flush with the body, and I just lay it right on the table. I've been doing it this way for years, and never had any trouble. Peace?

[Steelpriest]

guitarzan said:

When I lay the guitar on the table, I make sure the headstock's over the edge of the table. It doesn't touch it, and the guitar sets flat.

Same way as I do usually. I was not speaking of the headstock touching the surface of the table and the neck thus being bent forwards. I was speaking of the neck being bent back by its own (the neck´s) weight. This effect is very slightly though, but you can prove it. Tune your guitar, with the head over the table, bring it to playing position and control it with a good quality tuner again. The tuning of each string will definitely be a little bit lower (just a very little bit). Or maybe just let ring the open strings of your guitar and then move the guitar (holding it in your hands only at the body) from a playing position to other different odd positions, you will easily notice AND hear what I meant.