i need to make 10 columns, 14" square , 72" tall. i would like to use azek 3/4" 4'x8' sheets. i plan to cut 2 pcs 14x72 and 2 pcs 12 1/2x72 and glue and nail them together. azek pvc glue and 18 g. brads. does the pvc glue fuses the material together? the columns will slide over a build up 6x6 pressure treated post. will the butt joints be strong enough with the glue and brads? thanks for any help.