I wanted to add some additional information about the way that I reinforced the hull of MaJic Carpet. For those following my rebuild you will recall that the first thing we found out about this boat when we pulled it from the water was that it had taken a hard hit to the keel. Close inspection on the exterior of the hull found no damage at the front or rear of the keel. The small indication at the rear of the keel as it met the hull turned out to be just a lap of the glass work. On the interior though there was indication that the hull had flexed pretty hard, but not to the point of cracking any structural glass work, just some of the goofy vermiculite around the keel sump.

So prior to doing this work to replace the sole I decided that I would reinforce the hull somewhat. So I did add some glass on the sides of the sump and at the rear of the keel. Then I add two diagonal braces that are intended to be structural stiffeners. The bits that I have added to support the new sole are bonded to the hull and would have the effect of stiffening the hull, but that is a secondary effect. They are mainly intended as just supports for the sole. If they cracked away from the hull after the sole has been reinstalled that wouldn't bother me.

I didn't take the change of the structural design of this boat lightly. There are always implications to modifying a proven design. In my case I thought it important to stiffen the rear of the keel, but so far have done nothing for the front side of the keel. The rear section gets highly compressed from a keel impact, the front section gets super high tension. In general FRP does better in tension, but there are limits. I'm not sure how many of you saw this post:

J30 Keel Failure

After seeing these images and knowing that I intend to reglass the entire bottom of my boat after dealing with the core issues it occurs to me that adding some additional reinforcement at the front of the keel may be worthwhile. Particularly if there is some unseen cracking from the keel hit. Also after seeing these images I don't think that a new structural member at the front of the keel sump would have helped stop the keel failure. Trying to get something structural at the front would also be very difficult to do, there just isn't much space to do anything below the main bulkhead.

I am not too concerned with one design issues, just in maintaining the structural integrity of the boat. I just hauled off all of the old bits of the cabin sole and the vermiculite and I suspect that all of that old stuff weighs much more than my new sole and the new ribs and reinforcement that I have done. Albeit that was never the intention of this part of the repair.

Dave Graf