I have a small project (old pattern called a book house) I am making for grandchildren's school's annual fundraising The plan called for the back to be piece of 3/4" plywood approximately 13"x13". I have LOTS of plywood cutoffs courtesy of a local contractor's cabinetmaker but nothing the right side. I can easily butt glue two pieces together to get the right dimension but will it hold? Would backing the glue joint with a piece of wood work?