[PaulProe]

Ron,
The ERA instructions show them going thru both skins, getting a "double-purchase" which should be OK. Clamping on just the outer skin would be inviting trouble.

That leaves me with probably having to form some type of counterbore. Won't be easy since the door is already bonded together.

Maybe a fiberglass tube to accept the ferrule and a bigger tube to house the nut on the inside. Just thinking out loud

Paul