Re: 1971 larson boat (fiberglass). BAD crack in the back.. Whats the best way to fix
I'll try not to be too long winded (I have a tendency for long posts).. Glass repair 101: if a crack goes all the way through the laminates, the crack needs to be ground down and tapered on both sides of the face (typically a 12:1 taper; so an 1/8" skin should be tapered around 1.5 - 2" on both sides of the crack, 1/4" skin = roughly 3" taper; etc.. both faces of the crack).
***You're looking to replace the damaged area from both sides.
Clean and prep with acetone then lay up glass with resin; final layers with CSM (chopped strand matt 1.5oz). So, looking at your transom, you have grinding to do on both sides of the outer skin (the side of the transom in your pic) as well as both sides of the inner skin (the side not shown). You're transom thickness is only 1.5", so it's going to be a little difficult to get at both inside faces of both skins (if that makes any sense
). That's the only reason I was suggesting the approach I did. Like I said, normally I would agree with the cap method; however, not in this instance. Again, just my $.02
As far as the stringers, drill a small hole in the center of the stringer and catch the drill shavings. If they're clean and dry, you're good to go. If they're dark and wet, then time to do more searching on the forum.. Hope this helps!
I'll try not to be too long winded (I have a tendency for long posts).. Glass repair 101: if a crack goes all the way through the laminates, the crack needs to be ground down and tapered on both sides of the face (typically a 12:1 taper; so an 1/8" skin should be tapered around 1.5 - 2" on both sides of the crack, 1/4" skin = roughly 3" taper; etc.. both faces of the crack).
***You're looking to replace the damaged area from both sides.
Clean and prep with acetone then lay up glass with resin; final layers with CSM (chopped strand matt 1.5oz). So, looking at your transom, you have grinding to do on both sides of the outer skin (the side of the transom in your pic) as well as both sides of the inner skin (the side not shown). You're transom thickness is only 1.5", so it's going to be a little difficult to get at both inside faces of both skins (if that makes any sense
). That's the only reason I was suggesting the approach I did. Like I said, normally I would agree with the cap method; however, not in this instance. Again, just my $.02As far as the stringers, drill a small hole in the center of the stringer and catch the drill shavings. If they're clean and dry, you're good to go. If they're dark and wet, then time to do more searching on the forum.. Hope this helps!
