I had a similar problem, but didn't have to remove all the foam. My hull would ooze water for days when stored on its edge.Hi,
I am working on an old sunfish...it takes 3 guys to lift and sits in the water about 2'' from the rub rail. the foam must come out!
That's been my experience as well. Good or new foam does have structural value. Soaked foam is no better than a sponge. In fact, when removed, it can be used as a sponge!"...it seems the foam has some structural value to it as well. i have worked with old boats before, and once foam absorbs water, it is usually shot. it can be dried but once it gets wet again it soaks the water up like a sponge..."
I'm all for sentiment, but you need to sentimentally enjoy sailing this boat once again. Try drying it in the sun as above. Water will run out fast—at first—through the drain amidships."... especially when it is this old. my plan was to remove and not replace it. it appears i may need to strengthen the hull after removing the foam...i'm not going to race this one. the resto is more for sentimental reasons i'm not really concerned with keeping it 'legal'..."
A good observation, Dan. My account was from a clonefish—a Porpoise II—though it's been joined by a '76 Sunfish."...By the many accounts here, Sunfish seems to use higher quality foam than other builders. It recovers without degradation more often than in other boats..."
Take it from me...the deck may be stiff for your weight, but the bottom will "oil-can" once it starts hitting the waves."...i think i removed about 25 lbs of wet foam. I'm not sure if i will replace it with new foam, make a wooden support for under the deck to go in its place, or leave it out completely. the deck is fairly stiff without it..."
My Porpoise II clonefish doesn't oil-can."...You sure you aren’t thinking of a different make of boat. I’ve not seen that behavior in a Sunfish. Don’t expect anyone ever would in that spot...Oil-canning happens in the flat expanse between keel and chine on boats where the side foam supports have come loose and the flat sheet of fiberglass is allowed to flex more because the support has gone missing.
Hmmm. My '76 Sunfish—which has decals indicating a racing history—has an aluminum lip and no visible groove. The hull was pointed by the previous owner, so now I'm wondering if the hull has been sanded within a millimeter of its life!That’s the rudder plate carriage bolt groove. Every aluminum lip Sunfish I’ve owned showed that groove. Not until I picked up a newer rounded edge hull did I see it disappear. Good bet the groove is there on your '76 hidden behind the new style gudgeon plate.