generally you leave the inner section of the rings in (not cut out yet) then you mount a 2x4 to the center by screw and screw the other end of the 2x4 to the box. Once you glass just unscrew both ends and cut out the center. fiberglass holds the rings in there.after you glass it do you break off the ring supports??
if they are peices of wood screwed in how would you go about removing the supports?
exactly! i wouldn't leave the dowels in, cause i wouldn't want one to break. but if you use pieces of wood and screw them in, leave them there. they make excellent reinforcement.if they r not in the way leave them in thats what i have done