I'm grain filling an ash body. I bought some Deft Lacquer Sanding Sealer and some Timbermate Mahogany grain filler today. I've read that I should shoot the body with sanding sealer prior to grain filling, seemingly so the grain filler doesn't stain the wood. Where I'm unclear is the details. How many coats of sanding sealer should I do BEFORE grain filling? Just a light dusting or two? 2 full coats? 4 coats? Do I need to sand it back before grain filling? If so, how long after my last coat should I wait before sanding back? If not, how long before grain filling? Also, what does everyone mean when they refer to a sanding block? Is it a sanding sponge or something else? Can someone link me to a picture or a product?