Actually, Marty,
Marine may actually mean something when attached to 'plywood'.
Interior plywood can be pretty much steamed apart. The glue? Minimal tolerance to moisture and don't get it outright soaking wet.
Exterior? Upgrade in glue to more wet resistance. Good for roofing and underlayment of flooring.
Marine? I don't know if that is a separate category, but it would imply a VERY waterproof glue. Some marine glues will even withstand boiling water.
You CAN but shouldn't use interior plywood to make a boat. If you got a single season out of it, you'd be way-lucky.
Void Free is MUCH more important to the cabinet builder and generally, the more plys the better.
As an aside, I have shelves made from 1" MDF. But this is MDF on steroids. It took 2 people to move a 4x8 sheet. You can't even dent the edge with a fingernail and it almost doesn't float. It is almost dense enough to use metal tools and put threads in it (tap). I have no idea where my buddy got it, but if I were in a speaker building mood, this is where I'd start. It was expensive, too.
Marine may actually mean something when attached to 'plywood'.
Interior plywood can be pretty much steamed apart. The glue? Minimal tolerance to moisture and don't get it outright soaking wet.
Exterior? Upgrade in glue to more wet resistance. Good for roofing and underlayment of flooring.
Marine? I don't know if that is a separate category, but it would imply a VERY waterproof glue. Some marine glues will even withstand boiling water.
You CAN but shouldn't use interior plywood to make a boat. If you got a single season out of it, you'd be way-lucky.
Void Free is MUCH more important to the cabinet builder and generally, the more plys the better.
As an aside, I have shelves made from 1" MDF. But this is MDF on steroids. It took 2 people to move a 4x8 sheet. You can't even dent the edge with a fingernail and it almost doesn't float. It is almost dense enough to use metal tools and put threads in it (tap). I have no idea where my buddy got it, but if I were in a speaker building mood, this is where I'd start. It was expensive, too.