by PickerAUS » Tue Sep 29, 2009 5:51 pm
*** Do this at your own risk***
I have a who has fixed bent necks. It's a reverse pressure process and you can do it yourself:
1. Unstring it.
2. Site down the neck from both ends and work out where the bend is. If it's around the heel and if the heel is not loose then you use a counter weight.
3. Mark (crayon) where the bend is.
4. Build a simple clamping rig. You need 2 large carpenter's clamps (more is better), 2 straight hardwood planks (or 4 old floorboards) cut to size and time.
5. Straddle the bend on both sides with the clamps, using the planks as sacrificial pieces, one on top of the fingerboard and the other along the neck. I suggest you pad both planks with heavy cloth so it like a sandwich- plank-cloth-neck-fingerboard-cloth-plank.
6. Screw the clamps down medium to hard. Check the bend every 24 hrs for signs of improvement and don't overdo it!
If it's at the heel, then place the guitar on a table, fretboard up with the neck overhanging.
Clamp the heel/neckblock with cloth pads in place, weigh the rest of the body down with books, bricks etc and hang a weight off the 2nd fret. About 2-4kg (5-10 lbs) should do the trick. Check every 24 hrs.
Mind you, he uses guitar 'forms' and straps the body down. He also made a matching reverse that cups the back of the neck.
Re-string with light strings.
The proper fix involves taking off the fretboard, routing a channel and gluing 2 metal strips in the channel (on their edges, side by side), and replacing the fretboard or making a new one. The idea is that you don't overstraighten the neck.
He also used a small fan radiator to keep gentle heat on the spot if it's accessible. Steam can also be used, but too much will loosen glue joints as most older guitars are built with hide or fish glue and are prone to 'creep' in high humidity.