When the big box stores told this client to “just buy a new guitar”, I helped this guitars’ owner restore this sentimental 60′s gem. Here’s how I repaired this severely warped guitar neck:
Guitar necks have a lot of stress put on them, the tension of the strings and the counter-tension of the truss rod, and that is under normal circumstances. Leave a guitar in a hot car or a humid attic for too long and you might start to see the effects of that strain. Here is a guitar neck that was purchased in the 60′s and at some point left in storage somewhere for who knows how long. The neck warped so badly that the fretboard popped off and broke into pieces.
The first step was to clamp the neck in a way that would allow the flat surface to be accessed. Using a surrogate body made of 2x4s and a slight modification to my neck-tension jig, I was able to get the neck clamped in a slightly back-bowed position. The black bar is a straight-edge checking the flat surface. These handy eye bolts have a nut in the middle that lets them push or pull by turning the nut, three push up from underneath while two pull down on either side of the headstock to correct twisting.
Next I CAREFULLY applied the same forces that warped the neck to warp it back: heat, moisture, and time. A household iron works great to apply a safe amount of heat, with a stainless steel Stewmac straight-edge on the surface to evenly distribute the heat. I had a glass of distilled water on hand to strategically wet the wood (do not use steam from the iron!). A few heat & steam treatments later, the neck was straight as an arrow.
The original fretboard was gone so this one had to be built and cut to the right taper before gluing it on. This particular guitar had one more little challenge: a bridge without movable saddles. That meant that the placement of the fretboard was crucial, being off by more than a few thousanths of an inch would put the intonation off enough to sound ugly.
In order to place the fretboard with that kind of accuracy, a much more sensitive measuring tool was needed: a strobe tuner!
The harmonic at the twelfth fret marks the exact center of the string so I installed the zero fret and the twelfth fret to find that sweet spot with just some double stick tape holding the fretboard in place. Then some nails through the inlay holes to align it again before gluing. After some new additional work on the tuners and electronics this restoration was complete and looking great!