Jack,

Through Kayak Sports I've talk with one person that installed these with 6 or 8 #4 flathead screws and sealant. They've also heard of one installation with screws and adhesive.

I bought (6) #6 machine screws with oval heads yesterday. That's all the hardware store had. I'll have to carefully bevel the holes in the plastic flange without punching all the way through. I'll drill the holes tomorrow. The deck goes on tomorrow so the actual attachment of the day hatch will be later in the week after the glass and fill coats go on. With the beveled holes the screw heads, I don't think will interfer with the hatch seal. I plan to use the sealant. I like your idea of easy replacement. I can always go to the adhesive if the sealant doesn't work out.

Thanks,

Gary B.