Final sanding of the neck
by Chris Bewick
After last weeks rasping session it was time to bust out the sandpaper and start refinining the shape of the guitar neck. I began by tidying up the headstock transition using 80 grit sandpaper. This was probably the hardest part to get right because it’s a fairly abstract shape and it has to be gradually blended into the neck in several planes.
In this photo, the worst of the rasp marks had been removed but the transition is still fairly bulky and not very aesthetically pleasing.
I continued to work my way down the neck using a sanding block made from a scrap of maple. By using a flat block and going along the grain I was hoping that the sandpaper would act like a plane and ensure an even neck profile. It was in doing this that I became aware of several dips that I had inadvertently created due to over-zealous rasping.
To better highlight the location of the dip I lightly scribbled over the affected area with a pencil and then continued to sand. The graphite quickly rubbed off the surrounding wood leaving a clearly visible darkened hollow.
Once the neck was even and had been thicknessed to 21mm I began work on the heel transition. This was much easier than the headstock transition because it was a simpler shape and was symmetrical.
In the above picture you can clearly see a difference in colour between the freshly sanded neck and the grubby unsanded heel. This set alarm bells ringing and I quickly realised that I would need to put the oil finish on the neck sooner rather than later otherwise it would soon get grubby again once I had finished sanding.
After cleaning up the remaining parts of the neck I was satisfied that the neck had reached its final shape.
I moved on to 120 grit sandpaper and began to further refine the surface of the wood. After this I progressed through 180 grit, 240 grit and finally onto 320 grit.
A slight complication with this process was the almost black ebony sawdust from the fingerboard getting rubbed into the grain of the now gleaming white maple. Regular sandpaper changes and only sanding along the grain both helped to greatly reduce this problem.
In this photo you can see the remnants of the router tear out from earlier in the project. Although it is still noticeable it will be totally concealed within the neck pocket of the body once the finished guitar is put together.
There are still several neck tasks remaining. I have to drill, glue and finish the side dots, I have to partially resaw the fret slots and I haven’t yet cut the nut slot. Despite all this I decided to go ahead and apply the finish the back of the neck to prevent it from getting grubby or dinged during the remaining tasks.
I wanted a fairly matt/satin finish with as natural a colour as possible. With these criteria in mind I decided to use finishing oil.
I applied a generous coating of oil to the back and sides of the neck using a soft cloth. The fingerboard was still masked off from the earlier rasping and sanding work. Straight away the wood soaked up quite a bit of the oil and turned a much richer colour.
After the neck had been left to soak in and dry for one hour I got a clean cloth and buffed the finish.
I was really pleased with how the oil finish had turned out. It wasn’t too shiny and it had brought the best out of the maple’s understated grain. It had also made the ebony on the side edge of the fingerboard a very deep, dark brown.
The neck will definitely require several more coats, but for now it needs leaving overnight to fully harden off.