Repair a circular saw cut in the hull

[Bvc]

When taking some of the old floor out the adjustment came loose on the saw and went through the bottom of the boat I read two layer with fiberglass cloth and resin on the inside but what should I do on the outside before I gel coat it it's just the width of a saw blade about a foot long

 

[tpenfield]

Happens on this forum a few times a year. You do want to repair from both inside and outside, as well as filling the void from the saw blade.

 

[Scott Danforth]

you should do it from both sides. bevel the cut, then a layer of CSM on each side, then a layer of 1708 (assuming poly) on each side. fair, then sand smooth, then gel coat.

 

[alldodge]

Agree both sides, but use epoxy resin and on the inside use an additional piece of plywood and cover. Epoxy will bond to everything where poly needs help

 

[Woodonglass]

Duct tape the outside. Use thickened resin to fill the cut from the inside. (We call it Peanut Butter. Resin, Thickening Agent, With Poly use Cabosil and 1/4" chopped milled fibers, With epoxy you can use Sawdust or cabosil. Mix to the consistency of creamy peanut butter.) Once cured, sand/grind from about 3" away from the cut towards the cut and feather the middle. Apply a 1 1/2" wide layer of 1708 and then a 5" patch. On the outside use two a layer of CSM and then a layer of 1708 applied Fabric side down and CSM Side towards you. Sand, fair, Sand and apply gelcoat or paint. Done. This should take about an hour and a half from start to finish.

You can use epoxy if you want but...You can use poly resin too!
It's more than sticky and strong enough to do the job.