Re: Marine Plywood
Normal ACX can have any number of plies, depending on the mill and the mix of veneers.<br /><br />Marine grade tends to have more plies, as it is rare and expensive to get inner plies that are thick and also without voids, and no self respecting plywood mill or veneer mill would peel a thick peel from logs that would yield marine grade quality veneer.<br /><br />Most standard ACX plywood is made with outer layers only of group 1 wood, and only western production is made of Douglas Fir. Most of the inner plies are usually of a group 2,3 or 4 wood, as it is cheaper to use, and the face or back of the panel is what determines what group number stamp can be used.<br /><br />A plywood mill can build a panel that is stiffer than marine grade, and there are times, for specific reasons, where that is done (as in for the furniture frame industry)<br /><br />And it has everything to do with the wood, the grade, the species, and the specific construction of the panel.
