The amount of sanding required on the body varies from kit to kit. The solid wood bodies are the ones that normally take a fair bit of sanding. The object of the sanding is not to sand for sanding's sake, but to remove any machining marks and the roughness from end-grain exposure. You just want to achieve smooth round edges (where appropriate) and nice even flat surfaces. You don't want to put your finish on and discover that there's a 1mm dip in the middle of the body that's become obvious only after the finish has been applied.
If you are spraying the finish, spraying a light mist coat (a light 'dry' spray where you aren't trying to add a solid layer of paint, just enough to be visible on the body) before sanding the body (using a flat sanding block for the flat areas) is useful, as this will show up the high and low points of the body, with paint remaining in the dips and being removed from the high spots when you start sanding. If you do this, keep sanding until all traces of the mist coat have gone.
The ply bodies, like the GR1-SF, ES-1, ES- etc. really only require a basic light sanding with fine grits to take off loose grain fibres, as most of the sanding will be on the neck and headstock (using slightly coarser grits, especially if you've shaped the headstock yourself). And if you are staining or using Dingotone on the kit, then you don't want to use too fine a grit as this moves into the 'polishing' area and can prevent the wood from taking up the stain evenly. For staining, probably no more than P320. P1200 grit really isn't good unless you are spraying without staining, but even then, that is mainly wasted effort as the paint finish will hide any small imperfections, and you just need to build up enough layers of each coat (primer/colour/clear) to sand that back flat.
On kits like the GR-1SF and my ES-3, the neck pockets are large and there is a lot of surface area that will be glued and hold the neck in place. There's probably a least 4 times the area of an RCA-4, so even with a bit of roughness to the pocket finishing, there's not going to be any danger of the neck being loose. The most important thing is to ensure that there's no finish on as much of the mating surfaces as you can achieve. It's necessary to just go over the edges with your finish so that it sticks to the corners, but only by 1-2mm. Keep the rest as natural as possible for better glue adhesion.
So careful sanding to remove as much of the roughness as possible is good. Again, too fine a grit and so moving into the polishing area can cause its own problems. It's important to clean the areas to be glued so there are no loose fibres or dust in the join, so a quick suck with a vacuum cleaner whilst brushing the surfaces prior to gluing is beneficial. And clamping the joint tight whilst the glue is setting is of vital importance.
Reply With Quote
