During a 30 mile sail about a week ago, my gudgeon started to separate from my transom near the top. When I pulled the screws out, I found that a previous repair with a rivnut had failed. A second rivnut was still holding firm.
I removed the other rivnut, & drilled out the holes to 5/8". I found about an inch of wood backing behind the Luran skin & foam behind that. I then let a blow drier have at it for a couple of days to ensure that the core was crispy dry. When all looked good, I installed spiral wrapped fiberglass plugs in the 2 holes, using West System epoxy. The spirals went back about 3". After curing, I cut off the excess glass with a hack saw & filed the plugs flush. I pilot drilled 1/8" diameter about 2" deep & installed some #12 x 1.5" screws. It feels pretty darn solid now. It is probably stronger than new.
I removed the other rivnut, & drilled out the holes to 5/8". I found about an inch of wood backing behind the Luran skin & foam behind that. I then let a blow drier have at it for a couple of days to ensure that the core was crispy dry. When all looked good, I installed spiral wrapped fiberglass plugs in the 2 holes, using West System epoxy. The spirals went back about 3". After curing, I cut off the excess glass with a hack saw & filed the plugs flush. I pilot drilled 1/8" diameter about 2" deep & installed some #12 x 1.5" screws. It feels pretty darn solid now. It is probably stronger than new.