How neck angle changes with temperature/humidity

[edmonds]

Changes in the guitar due to temperature/humidity should be more apparent by observing changes in the guitar tuning. Do you ever notice that some days all the strings are slightly sharp or slightly flat, often by the same amount? I have not tried to experimentally correlate these, but I would guess that slight swelling of the top due to high humidity would tend to make the strings go flat.

[Narsil]

This is what happened to my all-laminate Norman last summer. I left it in my basement for a week, where the humidity was considerably higher than the rest of the house.

Upon playing it, all 6 strings had gone sharp. Not a huge amount, but noticeable, and fairly consistently for all 6.

Only thing I could guess was the neck (maple) and the fingerboard (rosewood) had expanded slightly. Yes, the little parlor has wood bracing inside (not sure what type of wood), and a rosewood bridge. I suppose it could have just as easily been those components that expanded.......now that I think twice about it.

Playability didn't appear to be affected.......but I ain't that great a player to notice minor changes like that.

Once I re-tuned it to play, and then moved it out of the high-humidity area........a few days later it must have returned to "normal", and thus was now slightly flat. Lesson learned !

[guitar george]

Originally Posted by tomiv9

I'm not sure it does affect neck angle. I know high humidity causes the top to swell, which raises the bridge and the action, and low humidity causes the top to sink, which lowers action. I always thought the neck angle was very stable, and only changes gradually over long period of time, due to stress on the guitar body, which causes the need for a neck reset.

I agree with this assessment in that the neck angle, being the angle between the heel of the guitar and where it is glued solidly to the top of the body, would pretty much stay the same regardless of humidity. (Unless the neck was loose or something), but, the tilting of the body in relation to the whole neck is affected by humidity as stated above.