I have dirt under my nails, and I'm not sure what(though it is pretty gritty) between my toes. Will this be suitable substitute for sand?'
Seriously, though...I split the difference between David and Rich. Either sand every single spot before applying the second coat of resin, or sand nothing at all. I think either one works. What I have found is that if there is not a consistent texture to the first layer of zpoxy and cloth, that there will be pits with not enough resin in them on the second layer. Not sure WHY it happens, but it frustrates me to hell.