Dennis,
Sorry to hear that you ran into trouble right after receiving a new guitar. It's always a disappointment when it happens.
Keep in mind that the guitar is more than 30 years old and has probably not enjoyed the best care for most of them. The problem you're describing is not an uncommon one and can be corrected with attention to the right area.
I've done the reapir many times over the years on both set necks and bolt ons...Les Pauls, 335s, SGs, Strats and Teles. It's not the humidity that caused this type of lifting beyond the 12th fret to occur nor is it changing tunings. The most likely culprit was the simple unpredictable movement of those particular pieces of wood used for neck and fingerboard as they aged and settled into what would become their final static position and shape.
Changing tunings should never cause an issue with the integrity of a neck or the builder should examine and change his materials and methods. Repeated and radical over-adjustment of a truss rod by someone who has no clue of how to set proper neck relief or even what proper relief is can cause permanent damage and distortion of the neck as a system of components. Not only will the rod break loose from its surrounding slot walls, but it will also stretch to certain extent since it is mild steel along its working length. The threads may be case hardened to provide some durability, but the rod stays soft for adjustability purposes and will stretch if pulled tight enough. The adjusting nut should be brass if it is a stock Gibson nut. Brass is used for obvious reasons to ensure that the nut is the part destined to fail if there is a problem since it is the easiest part to replace.
The way i've corrected the problem in the past is to prepare for a refret and then resurface the entire fingerboard face. While the frets are out and the truss rod adjusting nut has been lubricated and replaced with a fresh one from the manufacturer, I make sure that it is positioned to allow adjustment again. THe type of rod used back then was a one way adjuster that would simply adjust the neck in compensation for the effects of string tension by provide less relief then the strings would pull into it.
Once the surface is returned to as close a radius and flatness as possible to its original state, the new frest can be installed and a set up can be performed to achieve factory specs again.
With the affected area falling above the 12th fret on a Les Paul, I wouldn't bother with the heat application to soften the glue joint between the fingerboard and neck barrel since it won't be very effective that high anyway. I've used a neck heater to correct neck shape problems along the truss rod affected length but not outside of its working limits.
Let me know how you make out with it.
Kevin Gallagher/Omega Guitars
|