Think I may be doing something wrong with the grain filling but I'm not sure what. Each time I apply it, let it dry, sand it back, but as soon as the surface starts to get flat, it seems the grainfiller is just getting stripped out again. Am I using too low a grit (240)? Do I need to be giving the body a turps wipe before using the filler? Or prepping it in any other way? Am I just being too heavy with the sanding back?
Any suggestions gratefully received!