Q: Dear Boat Doc, a few of the snaps on my boat that secure the boat canvas have pulled from their holes in the side of the cabin. How can I best replace these snaps?
Amy Cavlin North East, Pennsylvania
A: Amy, the male snaps fasten to the boat using either a wood screw or a machine screw. The wood screw is typically a No. 8 size (diameter) and 3/8 inch in length. If they pulled clean without damaging the fiberglass, you can source snaps with longer screws, usually 5/8 inch long. You may also be able to modify a snap by removing the screw and inserting one of a suitable length.
Also, if you can get to the inside/other side of where the pulled snaps are installed, you can drill the holes out to a clean size, fill them with epoxy filler, and then drill and use the snaps with the machine screw and a nut, which will increase the holding power.
If you cannot get access to install a nut on the back
side, drill the current snap holes out to three times their current diameter. For a No. 8 screw, that means a 5/16-inch bit. Fill with epoxy. After cure, drill for the No. 8 snap-screw pilot hole with an 11/64 bit.
Do not glue dowel, matches or similar material into the holes for the screw to bite. This technique is not meant for long-term repair. The wood will soon turn soft, and the snaps will pull again.