Originally Posted by ctl411
What design flaw?
The 1976 Hunter 27 had a recess in the bottom of the hull that the keel fitted up into. If you look in the bilge you realize that in order to make that recess in the bottom the stringers that go over the top of the keel are nearly cut in half at the middle. This reduces their strength by 4 times! There are only six stringers, about 12" between them, and the keel bolts are centered between the stringers on this large flat surface. On my boat that flat surface delaminated almost completely and the keel pulled the bolts down about 2"!
In fixing it I ground away all of the stringers completely, as well as most of the thickness of the hull over the entire keel area. Then I made new stringers placing them only 6" apart and glassing it all with many layers of woven roving and epoxy resin. Then I made large stainless plates that each fitted over two of the keel bolts. I used fabric reinforced conveyor belt under the plates to keep any hard spots from being crushed. I also installed a new bilge pump. After the keel repair though all we ever needed was a vacuum cleaner for the dust.
In 1978 Hunter replaced the recess with a short outward stub for the keel. Thus the stringers were now twice as thick as before at the center, and 4 times stronger.
On my current boat an Etap 26 the designer also made a huge flaw in not directly tying the retractable keel trunk directly into the hull stringers fore and aft. So the keel trunk pushes its way down through the hull and pulls the mast step down with it. The mast tabernacle tilts forward, binding the keel lift mechanism. Once I started writing about this issue with my boat on the owners newsgroup I found out that nearly every boat of this model suffers from the same problem.
I also rebuilt the swing keel on a Catalina 22. I seem to have an attraction for boats with bad keels!
Gary H. Lucas