A 1/4" hole is small - is it a bullet hole?
Not entirely sure what that schematic is saying
I would grind out the hole a tad, both to clean it and turn the hole into a tapered shape \ / (wider on the outside - so plug
can't "pop" through).
then force in thickened epoxy
(it will slowly "droop" down the inside of the hull
- which prevents the epoxy
bung simply popping back out)
and then grind the outside of the hull
, and depending on thickness you have to play with, add a layer or 2 of cloth (or 3. or 4
Would very much prefer to also patch on the inside - especially if underwater. Above water
would be more relaxed. a bit