. We want to build this out of hardwood plywood for durability and strength, as this cooler is designed to hold several hundred pounds of ice and drinks. Build the box to be exactly 1... for the metal liner to be installed. Cut pieces of inch Styrofoam insulation to fit inside the plywood box. Cut the two side pieces first, and place them along the long sides... to avoid water in the walkway or party areas. Next is to attach the lid, and add the hardwood decking to match your deck. For the lid, use the same hardwood plywood you used to build...