Saturday, 23 November 2013

Les Paul Jnr Double Cut: Preparing a Solid Body for Wudtone

Before adding Wudtone to my Les Paul Jnr, the wood surface must be prepared - and that means more than a few a few hours of sanding, sanding and (you guessed it) more sanding.

My standard preparation for solid body basswood guitars (without veneer or binding) is as follows:
  • A really good sand with 240 grit, taking special note of areas where there is glue (there shouldn't be much if there's no binding) and filler (bog). I usually go over the body at least three times as there is no worries about sand through and so on. What does 'go over 1 time' mean in this context? Well, I tend to sand in 'sessions'. Basically, in 1 session I keep sanding until I've had enough and walk away. This is a single 'session' and on average it consumes one regular piece of wet-and-dry, and just a little bit of my remaining sanity.
  • Move up to 360 grit sandpaper. I usually go over the body at least twice (2 sessions) with 360 grit.
  • Fill the grain pores with a slurry of Timbermate and water. Dilute the Timbermate until it is like runny custard and then brush it on with and against the grain. For basswood I usually use a 'Maple' colour. For mahogany I go with a darker 'Walnut' colour. It all depends how much you want the grain to stand out. If you love grain, then typically the darker the pore filler the better.
  •  Let the Timbermate dry completely.
  • Use 360 grit paper to sand down the Timbermate until it basically disappears from the surface of the timber. Don't worry, it's still there in the pores, but the obvious Timbermate colour is gone.
  • Switch to 400 grit paper. Give the body a light sand - not too much or you will undo all your good work with the Timbermate! The surface should be feeling very smooth by now.
  • Raise the grain of the wood using water in a damp cloth. Let the surface dry completely.
  • Sand the raised grain back down  with 400 grit paper.
This is my pre-Wudtone preparation for basswood bodies. For maple necks, I do all this, but without the pore filling step. This is as far as I go for Wudtone as more sanding makes it hard for the Wudtone to soak effectively into the surface.

Disclaimer: Many exponents of Wudtone strictly adhere to the mantra that you should only sand to 240 grit as preparation. Personally I find that sanding to 240 makes it almost impossible to achieve a high gloss finish. I've only completed one Wudtone project so far, so maybe time will out on this one. At the end of the day it is up to you!

For other finishing products, in particular Tru-Oil, it is important to sand down to at least 600 grit paper. When doing this, I repeat the last 3 steps (400 grit + grain raising) with 600 and each subsequent grit size. Typically, though it is only one more to 600 (to save my sanity more than anything else). I have read build diaries online where other builders continue to 800 an 1200 before dying and oiling. It is definitely the case that Tru-Oil finishes benefit greatly from finer sanding, as the smoother the surface is to begin with, the less wetsanding you'll have to do to get a nice smooth finish.