By Jerry Cronan
Putting a backer plate in an inaccessible area
Here is how I fixed an unwanted hole in the transom of a foam-filled boat.
- I drilled a ½” diameter hole on each side of the unwanted hole,then used a saber saw to connect the holes to form a slot.
- Next, I cut 4mm thick plywood into a football-shaped backer plat that would fit through the slot the narrow way. I attached strings to the plate, coated it with epoxy then slipped it through the slot.
- Using the strings, I turned the plate so that it covered the three holes and the slot. Reference marks on the plate helped me get it in the right position.
Mounting a cleat
This same basic method worked well for mounting a much needed cleat on a balsa cored deck. There was no access to the back, so it was a seemingly impossible operation. Here’s how I did it:
- I used the cleat as a template to bore and tap an aluminum back-up plate. Then I used the plate to mark oversized holes in the deck.
- I drilled the screw holes and cut a slot in the deck, centered between the holes holes. This slot passed all the way through the balsa core deck and lower laminate.
- I used a small wire to fish a string diagonally through two of the holes in the plate and the matching holes in the deck.
- I coated the plate with epoxy, pushed it through the slot and used the string to finesse it into position under the deck.
- I used a syringe to coat the top of the plate and fill the slot with thickened epoxy. Then I coated the bottom of the cleat and mounted it in position over the holes. I threaded the screws through the cleat and deck into the two plate holes without strings.
- Before tightening the screws, I pulled the string out, then put the remaining screws in the holes where the string had been.