There are so many conflicting opinions to do with painting (not varnishing) and finishing.  I am using a two can polyeurethane paint, which is, of course, very very thin and as you'll probably know, gives a very hard and shiny finish. 

Last night I applied the first coat, with a short-nap mohair roller, tipping it out with a 2" foam brush.  The finish was pretty good barring the inevitable specks of dust ~ despite wetting the floor and taking all other precautions.

Do I sand (wet) between coats with a 400 grit, or not ? Or do I just go ahead with the second (and final) coat after 36 hours ?  

Your comments would be appreciated.

Dave