Correct way to fill in a thru hull hole

[FishStretcher]

I don't know for sure yet how thick it is there, as I haven't pulled the thru hull. The hull changes sound just below that point when you rap on it, so it does seem to get thinner about there and on up the hull. I really was expecting more glass there.

Of course you have had yours apart, I don't know why I thought differently, other than we might be talking about a different spot on the hull. I hope there is more than 1/4" of glass there.