Not quite sure what your problem is .Screwing a sheet metal /wood screw through wood into Plexiglas tends to crack PG.Drill hole in PG then screw from PG through to wood just not too tight.Or best way is drill through both and install threaded screw and nut .A bead of silicone caulk around /between wood and PG before you snug down screws gives it a little cush ....cva34I tried to screw it and it didn't work. There must be a special techinque. Do you know how?
Seems to work better with flat screws not countersunk too