Best Plywood Projects (Luan)
Plywood is very good for work around the house or for shop projects like workbench plans. All large knots are replaced with football-shaped patches, which can be sanded and finished with the rest of the panel. Also, any gaps or voids along the edges of the panel are usually filled and smoothed off with wood putty. Using A and B grade plywood ensures a sold finish, and thier is a limited about of any repair work that you will need to do, to remove patches and whatnot to smooth the surface.
Project For Plywood: Floor Underlayment
Trying to Determine the Best type of Luan Plywood to use can be a bit of a challange. - Don't just pick up any piece of plywood. Make sure that the plywood you use it the right type for the job your looking at doing (underlayment) There is Resilent Plywood for Vinyl Flooring, and then you're using 1/4 inch exterior grade AC Plywood. Make sure that the plywood is smooth and the smooth side should be facing up.
For Wood Flooring 1/4 inch to 1/2 inch plywood exterior grade is best. There is no need to choose a grading here since smoothness is not an issue.
Marine ply is also going to have more plies than typical construction ply, you want to be on the look out for higher numbers, greater than 7 in my opinion. Marine ply is going to be lighter than ext ply and especially pressure treated ply. For your boat I would go with the Home Depot pressure treated varieties. Your best bet is to get 2 sheets of 3/4 pt ply, let them dry for a week, then glue them together.