I've used both pine and oak wood bases in the past. Some as large as 12"x10" with good results. Maybe some slight bowing, but nothing serious enough to have to do over.
I sand the wood good, then I apply a good stain, wipe off the excess and let dry. I will then apply 3-5 coats of polyurethane, fine sanding in between coats. The same even coats all around the board.
12X10 is about the largest I've done so far.