Rot Doctor


Subject: Prindle Cat Soft Hull (pt. 1)
Date: Tue, 30 May 2000

I have purchased a prindle 16 catamaran couple of weeks ago and have noticed that one of the hulls is soft. I didn’t know it was a problem until a fellow cat owner said that his hull broke in fairly light wind due to this problem.

My buddy and I had an idea of laying two opposing layers of fiberglass over both hulls forward of the crossbeam. Also thought of laminating thin fiberglass bars (thin battens) running lengthwise on the hulls. I only paid $600 for the boat and trailer (both in good shape) I just don’t want the boat to break up off shore.

Also there is no flotation in the hulls. So if one hull busted do you think the other air-tight hull would keep the boat afloat. I was thinking of trying to find a place that could pump foam into the very front and back of both hulls. Thinking that if something did happen the boat would still stay afloat so parts of the boat could be salvaged. Sails and rigging.

Does anyone have any insight on this subject? Should I try the fix or do you think it is a waste of time and money?

Thanks in advance for your comments

You are bringing back memories of my days working for a sailboat rental. Customers would take the boats out (mostly Hobie Cats) and abuse them all day, sometimes even breaking them, then we would fix them if possible. It was amazing how much abuse those Hobies would take. Until Coleman bought the company and started making the hulls thinner. Then the bows started snapping off. The thinner hulls just couldn’t take the strain of the forestay pulling the bows up and in. The new boats started showing stress cracks on the inside of the hulls just forward of the center crossbeam, and 6 months later they started snapping off. And yes, the other hull will keep the wreckage afloat. The broken hull, trampoline and rigging may be submerged, but the remaining hull will keep everything from going to the bottom.

As far as adding reinforcing, I guess that I would not use the method that you suggest. You didn’t mention exactly where the hull was “soft” or how much, but generally the best way to strengthen the bows would be to add a crossmember between the bows. A section of aluminum mast or boom that is long enough to go between the bows would add the stiffness that you want without much weight. If you went with the fiberglass cloth or bars method, you would have to add way to much weight before you got enough stiffness to make much difference.

I am a little curious about your use of the term “soft”. This is more commonly used in describing bad fiberglass in cored hulls, and I didn’t think that Prindles were cored hulls. As I said before, I’m very familiar with the construction of Hobie Cats, and they are solid fiberglass hulls. Do you know if your Prindle is solid or cored fiberglass? The construction of the hulls and the area and extent of the softness could make a difference as to what type of repairs/reinforcement I would advise.

As far as filling the hulls with foam, I guess that is kind of up to you. If you fix the problem with the soft hull, you don’t really need to, as the hull won’t break. I might buy a couple of access ports, add them to the top of the hulls, and fill some plastic bags placed inside the hulls with some of that super expanding foam.

Write back with further details or questions.