P-Bass (PBA-4)

[Simon Barden]

The neck is maple, so won't need grain filling. The PBA-4 has an ash body, and ash is a timber that requires grain filling (it has large open pores) if you want to a achieve a flat shiny surface on the body. Not everyone does, but you won't get a flat surface all over the body without grain filling it.

You'll want to sand the body as smooth as possible first before grain filling. This smoothness will depend on the finish you want to apply. Using too fine a grit can 'over-polish' the wood so that it won't absorb stain or wax well. A maximum of P240 is best here A sprayed finish will take on a much smother surface, but there is no real point in over-smoothing the wood as you will just have to repeat the process on the finish anyway. So maybe P320 maximum for a sprayed finish. If you are spraying over staining, then stick to P240 as a maximum.

Grain filling will leave a residue on the surface of the wood that will need sanding off, so try to remove as much of the surface grain filler as possible during application. Use a plastic or rubber-edged scraper. And I'd use a light surface sanding before the grain filler sets firmly, as its far less work to remove.

Grain fill twice, as the first application is bound to have missed some areas and the grain lines in ash can have deep pits that are best filled a little at a time rather than all in one go (just like filling any large hole).

[Shimmix]

The neck is maple, so won't need grain filling. The PBA-4 has an ash body, and ash is a timber that requires grain filling (it has large open pores) if you want to a achieve a flat shiny surface on the body. Not everyone does, but you won't get a flat surface all over the body without grain filling it.

You'll want to sand the body as smooth as possible first before grain filling. This smoothness will depend on the finish you want to apply. Using too fine a grit can 'over-polish' the wood so that it won't absorb stain or wax well. A maximum of P240 is best here A sprayed finish will take on a much smother surface, but there is no real point in over-smoothing the wood as you will just have to repeat the process on the finish anyway. So maybe P320 maximum for a sprayed finish. If you are spraying over staining, then stick to P240 as a maximum.

Grain filling will leave a residue on the surface of the wood that will need sanding off, so try to remove as much of the surface grain filler as possible during application. Use a plastic or rubber-edged scraper. And I'd use a light surface sanding before the grain filler sets firmly, as its far less work to remove.

Grain fill twice, as the first application is bound to have missed some areas and the grain lines in ash can have deep pits that are best filled a little at a time rather than all in one go (just like filling any large hole).

Thank you Simon! a lot of info, very helpful indeed!