High action on an acoustic guitar is a common complaint, and usually we can readjust the action on an acoustic by correcting the neck relief using the trussrod, and if necessary reducing the height of the strings by filing down the saddle. However, occasionally with an older guitar it is not possible to lower the saddle enough to get the action where it sould be for the guitar to play easily.
Traditionally the solution to this was removing wood, either by shaving down the bridge itself or by planing the headstock end of the fingerboard. Neither of these was a terribly good idea, and often detrimentally effected the sound and playability of the instrument. As the value of older Martin and Gibson guitars began to rise repairers began to investigate more sophisticated solutions to the problem, and the process of removing the neck altogether using steam to release the glue in the joint and then refitting it at an angle that would allow the guitar to be set up with the required action became the standard for correcting this problem in high quality acoustics. It's a great process as it's non destructive, doesn't change the character of the guitar and effectively resets it to how it would have left the factory rather than modifying it to something it wasn't originally.
In this diary post we're going to look at the process of resetting the neck of a 1970s Fylde guitar. Modern Fyldes are made with a bolt on neck design so don't require quite such involved work but the early ones have a dovetail joint similar to that found in a traditional Martin or Gibson design. Let's make a start:
1. Firstly we need to release the fingerboard from the top of the guitar. There are heat blankets made specially for the job, but an old iron and a block of aluminium to help disperse the heat does the job very well.
2. As the glue softens with heat from the iron we start to work palatte knives under the fingerboard to seperate it from the top. If the knife doesn't go in easily it needs more heat - we don't want to risk digging into the soft cedar of the top.
3. Once we have the fingerboard free from the top we can start working on the neck joint itself. To do this we need to drill a hole so that we can get steam into the joint, and the only easy way in that won't show is to remove the 15th fret and drill through the slot.
4. Here you can see the drill going in. Dovetail neck joints typically have an air pocket between the back of the neck tenon and the block, and this is where we're aiming so that the steam will have as much access as possible to the glue joint between the checks of the dovetail and the block.
5. We'll clamp the neck up in such a way that we can put gentle pressure on the joint by tightening the clamps. It won't take much so these cam clamps are ideal.
6. Next we need to work steam into the joint. This is a delicate process as we need enough steam to release the joint, but we want to avoid getting the guitar saturated with water or having steam getting into other joints. We do this as a two man job, one person controlling the steam and the other blocking off steam with paper towels and mopping up any water. That's my job, so I need to put the camera down and get on with it!
7. It doesn't take much and we can hear a telltale creak as the glue softens enough for the cam clamps to do their job and seperate the joint. A quick tighten of the cams and the neck slides out cleanly.
8. Hear's the exposed tenon. There's lots of old glue to tidy up and then we can start to look at adjusting the angle. First we're going to set it to one se=ide and let it thouroughly dry out. Notice this early Fylde has a non adjustable truss rod made from a square box section of steel - it's kept the neck admirably straight all these years.
Here's the joint from the body side. Again, there's quite a bit of clean up to do.
To Be Continued...