question about fastening tops to decks?

[pelican]

this is a repair i did a few months ago - the deck's cored with divinycell,the console was held in with silicone,and the t-top was atched to the deck with steel "toggle" style bolts...
the top pulled out,on all 4 points,the console was actually dislodged,and i was able to lift up on the whole assembly...


the boat was unrigged,t-top was removed,console removed - mounting points for the top were opened up and the core was removed to the inner skin,these areas were built to the original thickness,using alternating layers of 1808 and 3/4oz chop strand - built to approx 3/4" thickness.

upon reassembly,the top was mounted in the manner i described - the mounting holes were marked,and drilled 3/16",i used 1/4-20 oval head machine screws to atach the top to the deck - a shot of 3m 5200,was dropped where the mounting pads went,and in each screw hole - the screws were ran into the holes and tightened securley...

ocean yacht - viking yacht,these mfg's use this method of installing equipment.
there's no need to "tap" epoxy,or fiberglass,or lite thickness aluminum - all of these materials will accept a machine screw,when used in this manner - no helicoils needed.these screws will never back out,or pull...

as the pictures show: nida core is a honeycomb material - it has the worst screw holding capabilities,attempting to screw anything into that material,will result in a failed attempt...