When doing several coats what do you do in-between coats. Do you sand it if so to what grit? Does the next coat partly dissolve the first coat so they blend? Or will you see the scratches from the top of the firs coat through the second?

I sanded just enough to flatten out the bubble pops and depressions. I think I used 320. Dont worry about the scratches, they will disappear once you do the additional coats and polishing..

It depends on how long you left it to cure. If you did more than the 24hr full cure time, you'll need to use something coarser. The Epoxy book recommends something like 100 or 150 grit to allow for a mechanical grip between the coats. If you did less than 24hr, then anything that'll get rid of the craters and bubbles will do. That said, I always use 150 regardless.

Thanks it has been a few days. I will do the 150 tomorrow...t