delamination question

[sailinaggie]

I'm attempting to restore a '76 solcat 18 catamaran. The starboard hull has pretty large soft spot with delamination in the center of the area in question. Ive been reading up on different repair methods. I've read about drilling small holes in the outer skin and injecting epoxy to correct the problem. Is there a maximum size this repair method can be limited to?

Inside access to make repairs is pretty much out of the question, unless i take a big slice out of the deck.

any help would be greatly appreciated.

[Toot]

I wouldn't do it for a large repair. Are you down to bare fiberglass? Or are you working through the gelcoat or whatever?

If you're talking about a delamination from the core, then I think injecting resin would work. If it's a big enough void, you could even just pour it in.

However, if it's a delam between layers of fiberglass then I would avoid the injection technique on large areas is because it will act like a core material and be stiffer than the surrounding structure. As a result, the area around the glob of injected glue will take up more loads. If that delamination occured as the result of it being a high stress area, then you will be making the problem worse and you will have bigger problems down the road as you get a delamination around the edges of the previous repair. Now, instead of a nice round air pocket, you will have on that is the shape of your previous repair with a solid bond in the center... then you've really got a nightmare repair on your hands.

Instead, get a rotary tool and a grinding disk and grind on through and rebond new layers of FG. Ideal would be to scarf the edges of the new plies of FG, getting successively bigger as you work your way out to the skin.



CAVEAT: I am no boat builder, but I do a lot of composite work and was trained to do composite repairs on aircraft.

[oldtimer]

Hi
If its a cat mould a simular shapped piece of the other hull and use that as a muld and manufacture a complet new section complete with cores or what ever it is made of . Release it and place it over the soft place and mark it . Cut the old bit out and trash it . Scarff the new bit to fit the hole and glass it in , Cut a section of you deck so you are able to do some glassing from inside around the perimiter of the repair then finish off the repair on the outside of the hull fair and fill and paint Replace the section of the deck as well all from the outside .

[oldtimer]

Its not a good idea to inject resin into a soft area as patch could have water in it and the resin will never stick and possably new go hard . Just cut it out and get rid of it . Carefully with a grinder feather back the scaff section on both the new and the old and do a nice job !!!

[JR-Shine]

make a mold from the other hull, fix it from the inside