Originally Posted by Joe Videtto2
Is the temperature where the guitar is constant?
Originally Posted by Notes Norton
[quote=Joe Videtto2]<...snip,...> I find that several of my strings often become sharp after the guitar sitting for a day or two - not all, but I haven't really kept records.<...>

Well, I live in a house in NYC where we shut the heat off at night - so probably this explains it.

As long as the action doesn't dramatically change with temperature changes, I suppose I shouldn't worry about this.

Temperature will affect the tuning, and it doesn't affect all strings equally. Generally the heavier plain strings, and the wound strings with a heavier core, will go out of tune first. So with mild temperature changes, you may only notice a couple strings out. With larger temperature changes, all the strings will go noticably out.

Temperature changes don't affect action much at all. What can affect action is seasonal changes, where there are large changes in humidity. The neck wood will noticeably change in size enough to make the neck move and change the relief. When this occurs, an adjustment of neck relief (by a truss rod adjustment) is typically all that's necessary to correct it.

This change in relief will also change the action height, and this is often how you know that the neck moved and the relief has changed. But you don't want to simply readjust the action height. The saddles didn't move, the neck did. So If you simply readjust the action height, the relief would still be wrong.

The most effective way to deal with seasonal relief changes is to simply adjust the truss rod until the original action height is restored. No need to measure the relief itself. Restoring the action height will also restore the relief.

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