The thing that needs to be determined First of all, is this a Structural problem? Or is this just a hole because of some sort of damage like the picture of the over anxious boater who launched his boat before he got to the dock.
If this is Structural then the best way is the Only way to do it. If this is just a hole in a very bad location you could go with the easy way.
The best way:
Go in from the inside first remove stringer build up area that stringer was with woven roven starting with 3 pieces 18” wide then 3 pieces 12” wide the 3 pieces 6” wide in the area of the hole going 2 feet in front and behind then building a lateral bulk head from port to starboard stringer for additional structural support using lots of glass. Then you can use the vacuum bag approach or flip the boat and build up the bottom to approx ½” glass thickness then gel coat and bottom paint.
For me the Best Way is the Only Way to go.
But for the easy way:
Sand the bottom paint off and get to the gel coat 1 Foot wide on both sides of the center line and inspect for additional cracks grind a little further forward and back of the hole to confirm you got all the cracks out feather it out more, flip the boat or vacuum bag the hole and HOPE you fixed it instead of just putting a bandage over a skin cancer.
If you are right and someone worked on this area before than forget the bandage and go for the best way.
There is a lot of sweat equity in this one really not that much $$ to fix it. 2 Gal of epoxy and glass and Lots of Beer will do it. Getting to the area doing the work putting it back together again would be Lots of work.
FellowShip
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My motto: Just for the Grins
