QUOTE(zeroglyph @ Jan 1 2009, 11:15 AM)
i do agree however that minor changes on several part of the woods would definitely have more affect on tuning than minor changes on the strings(in regards to temp that is).
in a cold room, let's say 16°C, take the guitar and tune it right away... you'll feel that the higher strings are really cold.
once the guitar is tuned, start playing.. the bends, the slides, the friction.. all those are going to warm up the strings and your quitar becomes out of tune in a matter of minutes !
Therefore, the strings do expand and shrink quite happily with temperature ! They heat up to about 25°C/30°C I'd say. --> the tuning is getting flatter.
The rod inside the neck is also made of metal, but (as written earlier) it's protected by the wood... so the impact of T is taking more time. Yet, after a while, the rod will get warmer (if the room gets warmer), therefore more tension --> it will pull the head backwards --> more tension of the strings. The tuning is should be getting a bit sharper. However, i never noticed this...
The wood is not affected by heat (as far as i know !)
The glue... mmm... i'm not sure. If the glue becomes a little less sticky every time the t°C is getting higher, the neck will just snap away after a while, no ?