Pain In The Neck
This month Alex Bishop takes apart a 40-year-old acoustic guitar. But the question is: can he put it back together again?
If you are the owner of an acoustic guitar, the words you never want to hear your luthier utter are ‘neck reset’. These days innovative bolt-on neck designs have become commonplace, but most decades-old handmade acoustics are likely to have traditional dovetailed joins, combining tight-fitting joinery with the power of glue to withstand a lifetime on the road.
A neck reset is normally the course of action required when all other options have been exhausted; it is one of the most invasive repairs carried out by a guitar luthier. Essentially it involves removing the neck completely from the body, and fitting it back on again at a different angle. However the resulting change in geometry provides an opportunity to not only improve the sound but also improve playability.
The guitar in question was a 1984 Fylde acoustic, a beautiful-sounding instrument with a troublingly high action. The height of the strings is controlled by several factors, the obvious one being the height of the saddle. But in this case the top of the saddle had already been lowered to a fraction above the top line of the bridge, so reducing it further was out of the question.
A bowed neck caused by decades of string pull is another common cause for an unplayable instrument, normally rectified by simply adjusting the truss rod. However, this Fylde was made back when master luthier Roger Bucknall was using very stiff nonadjustable H-section steel bars, and the neck had somehow bowed despite his forward thinking with this rigid reinforcement. I could plane the fingerboard flat to straighten things out, but this would only further the distance between string and fret. And thus, a neck reset was in order.
Steaming Ahead
The first step was to detach the fingerboard from where it was affixed to the soundboard, up until the neck join at the 14th fret. I used a heat gun and a thin palette knife, gently separating the rosewood and taking care not to blister the finish with too much heat, nor damage the top by accidentally driving the knife into the wood grain.
The tricky part then came in trying to get at the dovetail join, hidden beneath the tongue of the fingerboard. Most neck joins extend into the body somewhere around the 15th fret, and I was able to confirm this by drilling an exploratory 2mm pilot hole through the fret slot. To my surprise, it was easy to detect the gap between the dovetail and the back of the mortice when the drill suddenly dropped into the body after only a few millimetres of drilling. The same pilot hole would then be used as an access point for injecting hot steam, which could percolate throughout the join, gradually softening the glue and allowing me to ease out the neck – at least, in theory.
My weapon of choice was a steam cleaner from my local hardware store, with a petroleum-grade rubber hose and fine-needle attachment to direct the steam. Once everything had reached the right temperature, I slid the needle into the recess and pulled the trigger. The scene that followed must have looked like a busy Victorian train station, as I was enveloped in a fog of hot steam, and began to wrestle the neck to and fro. Frantically mopping up water as it dribbled out of the heel and pooled on the workbench, I began to wonder whether it would ever release its grip when – clunk! – I found myself holding two separate pieces of guitar.
Steam gently wafted from the void in the top of the guitar body as I stood back to survey the scene. All in all I was pleased – the neck had come away quite cleanly, just a few stubborn slivers of spruce still cemented to the underside of the fingerboard. Now I would need to precisely pare away wood from the heel to completely refit the neck. First, though: tea.
My thanks to Roger Bucknall for providing detailed information about the guitar before I started restoring it. Both the guitar and I would have been worse off without his valuable advice.
“A neck reset is one of the most invasive repairs and involves removing the neck from the body and fitting it back on again at a different angle”