How to fix hole in catamaran

[Chris1956]

My neighbors Hobie cat banged into a piling during a storm and it put a good sized hole in the center of the starboard hull. The hole is 18"X30", with some of the hull pieces hanging by fiberglass "threads". Also the hull is a sandwich of thin fiberglass and foam core, and there is no access to the inside of the hull to repair it.

Anyone have a suggestion on how to repair this?

 

[flashback]

Re: How to fix hole in catamaran

Well It isn't easy when the hole is that large, It may be better to try and find a new hull.. that being said. one way to fix it is to get a 9 or 10 inch diameter inspection plate and cut a hole in the deck above the hole in the hull for access to the inside only don't install the ring or plate until the repair is done. Then using a grinder, enlarge the damaged area until you have cut away all the ragged edges and loose foam and glass, try to chamfer all the edges of the hole so it has a taper to it. then cut some backing out of cardboard, foam house board or something similar to fill the hole level to the inside of the hull and tape it with duct tape frome the outside. also apply a layer of wax paper to the inner surface of the cardboard to keep it from sticking. this is to support the inner skin that you will now start applying to the inside. layup the inner skin in pieces you can work with thru the access hole you cut in the deck. maybe strips about a foot long and 6 inches wide. once you have it laid up with 3 or 4 layers of glass cloth let it dry then remove the cardboard. now you have something to glue the core material to.. install the core material and glass over with the exterior skin then fair it all out and and paint... hope you have worked with glass before as I have left some details out but this is the basic approach to it..good luck... there are some books and manuals that you can get that will go into much greater detail...

 

[tashasdaddy]

Re: How to fix hole in catamaran

what length is it? suggest a salvage hull.

http://search.ebay.com/search/searc...from=R41&query=hobie&category0=&Submit=Search

 

[Chris1956]

Re: How to fix hole in catamaran

Flashback, Thanks for the counsel. I had thought of the opposite approach. After grinding the hole to a taper, ans sanding the inside skin rough, I was going to attach two pieces of heavy roving to a backer of 1/4 plywood, larget that the hole, saturating it with epoxy and slip it into the hole and wire it tight to the inside of the hole. This gives me something to glass to for the inside skin, foam and outside skin. It seemed easier that working through an access panel. Any thoughts?

 

[strizzy]

Re: How to fix hole in catamaran

Flashback, Thanks for the counsel. I had thought of the opposite approach. After grinding the hole to a taper, ans sanding the inside skin rough, I was going to attach two pieces of heavy roving to a backer of 1/4 plywood, larget that the hole, saturating it with epoxy and slip it into the hole and wire it tight to the inside of the hole. This gives me something to glass to for the inside skin, foam and outside skin. It seemed easier that working through an access panel. Any thoughts?

T
hat will work fine. When I use to be around the local cat regattas, they talked about using t-shirts and such for what you’re doing with the plywood. The “ideal” way would be to use an inspection port (may have to add these). But doing it that way should work fine. (damns self once again for selling the Nacra)

 

[flashback]

Re: How to fix hole in catamaran

that will work also, and maybe even better... the only thought I have is the weight difference.... If you don't race the boat then no worries..... If you do race the boat and loose a race you can blame it on the extra weight..dd and strizzy,,, YES ,,, the narca is a great cat.. light, fast, and strong... you need to get it back..dd