ferminj

Those cracks don’t look too good. It looks like it is on the panel that you cut out so the repair will easy to get at. The cracks have to go away you will need to grind the foam out clear through to the outer skin. Make sure you get all of the damaged foam removed then about ½ inch on each side of the crack taper the foam about a 30-degree angle outward towards the inner skin. Then I would lay-up two layers of unidirectional cloth about 6-8 oz weight tying the outside skin to the inside skin. You can fill the void with a bog made epoxy and a filler chopped glass and fill in the void level with the inner skin then lay-up one or two layer of over the patch area to pull it all together overlaying the area by several inches. Look on the outside of the hull my guess if you have kind of damage on the inside you have cracks on the outside also, or maybe it's just soft there.

You need to build a lip for the deck lid. That is going to take some creativity. Looking at the picture the flange needs to be curved in shape. I would make it out of solid glass and you need to try to tie into the top and bottom of the damaged area if you can. You’ll need to grind into the area near the opening to get a good bite into the old glass, perhaps 2 inches. Looking at Turbocat’s picture of the new laminates, I take it you are going to get new laminates? If not, even the old laminates I’d mold off of them. Look at the picture of the new decks as they sit sailing side down there is flange around the edge of the laminate. Use a good quality duct tape and tape off the edges both sides top and bottom. Cut some cardboard from a big box and extend the edge of the flange out several inches as needed to tie into the flat part of the deck, you will need to go further but that will be the next step. Tape the cardboard to the side of the deck that is the actual top as it sails. So as you are looking at the picture in the post you have the upside deck lid (tubes up), tape, the deck lid, tape, cardboard. If you make the cardboard flange you can actually fit it in the hull to check for fit. Once you have your cardboard flange taped down to the deck tape out the cardboard. Wax everything with mold wax it you have it if not a paste car wax. If needed you can make the flange in pieces. I’d lay-up a flange with enough thickness to equal what was there. Now that the flange is made you need to attach the flange to the hull. Make sure you use Acetone or the like to remove the wax and sand some to skuff it up. I like pop-rivets or drywall screws just a few to hold it in place and dry fit everything. Grind and fit as needed. Once everything fits all right, remove the pop-rivits or screws, and glass in the flange you made and overlap it some in the hull on the top and bottom.

There is one other way but it may be more work and that is to cut a few access holes in the inner side of the hull to work through and glass it up directly then patch the holes with flanges. I had to do that with my G-Cat because the deck is one piece. I have some pictures on my website of making a flange repair http://themanshed.net/archived-projects/g-cat-catamaran/?g2_page=2 and page 3.

West systems has CD called How - To Basic application, fiberglass/composite repair, and gelcoat blister repair using their products Catalog Number 002-898 it was free at West Marine for awhile when you purchased some West Systems Products. It is general information for all repair work.

Mike