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Old 08-24-2012
gknott gknott is offline
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Re: Compression post issue

There have been quite a few discussions about this issue over the years and searching back in various fora might help. The original design by Bob Perry had a keel-stepped mast so the fault lies with Islander for changing the design during production to create a more open interior to sell boats. I'm inclined to think that most Islander 28s will have this problem which on my boat occurred not only on the cabin sole but also where the metal post sat on the horizontal countertop. The problem is plywood under compression loading perpendicular instead of parallel to the grain. Although the early Islanders were constructed with extremely high quality Bruynzeel plywood, the production Islander simply asked too much of the materials. I jacked mine up with the mast in place and found the process nerve-wracking (expect creaks and groans) but possible. I had to make up about an inch so I replaced the plywood in both locations with stacked 1/4" aluminum plates, one spanning the two cross beams in the bilge and the other a disk between the steel and wooden post at countertop height. I was rightfully reminded to insert a dielectric material between the dissimilar metals on another forum. If I had it to do over again, I would: 1) take the mast down first and, 2) strongly consider giving up the off-center kludge of posts and do what Bob Perry seems to have envisioned. Give up the space and squeeze by a single post centered on the keel. However, this requires advanced boatwright skills and slim and agile sailing companions and for those of us more interested in sailing rather than fixing boats there is always the option of simply ignoring the problem because I don't view it as a critical safety item for the casual sailor. Then again, I am risk-tolerant and I firmly believe that the next meteorite to strike the planet will not hit me. Others may disagree....
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