After you have shaped the foam mark and cut the holes for the outlets and the blower to go into.  Cut these holes slightly undersize in the foam as they will be fine tuned later. Spread a thin coat of resin over the foam and lay one layer of glass over the resin and out ont the rim of the lid to form a flange to use to secure the blower unit to the lid.  Apply more resin as needed to thouroughly wet out the glass.  After the resin dries sand off any rough spots.  You can now apply a second layer of glass if you choose.  I only used one layer and am pleased with the result.  Cut out the openings and sand for a snug fit of the outlets and the blower.  A razor knife works well for this. Cut the 3 inch PVC coupling in half to make the two outlets. If the blower has mounting legs just cut them off and sand smooth. Insert the outlets and the blower and apply a bead of clear or white paintable caulk around the outside of them.  Be sure the air flow from the blower is pointed down into the unit. Not sucking air out. Caution the cured fiberglass is very sharp and will cut you !.Carefully release the fiberglassed box from the top of the cooler lid.  Work a knife blade under one edge and work it all the way around the peice.  The fiberglass will easily release from the duct tape, as it will not glue to it.  After the blower box is free from the lid turn it over and remove a very small amout of foam from around the outlets and the blower and the fill the space around them with resin.  this will lock them securely in place.  The paintable sealer on the other side acts as a dam to prevent the resin from running out onto the front side.  Set the assembly aside to dry.


After the resin is dry trim the excess fiberglass from around the edge with a pair of scissors being sure to leave the flange that was formed for mounting the unit to the top of the lid.  Sand all sharp or rough edges mask the oulets and blower with tape and paint the outside with the spray can color of your choice.