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Join Date: Nov 2008
Location: Tampa Bay Area
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Re: Benataeu grid construction
I suppose more specifically, I'm trying to find out if there's anything worth investigating that can put some doubt on the results. Or are these results concrete?
Is this a sign that the stringers and framing are destroyed? Or could they be intact and the bones are still solid?
Any chance what the surveyor found as delamination is only cosmetic? Or is there no doubt that this sailboat is no longer fit for use?
Those are cracks in the gel-coat surface of the structural grid and will develop over time as the hull works. The more important issue is the integrity of the lamination between the grid and the outer hull which is intact. FYI, the structural grid is laid up as a solid element and then cut-outs are made between the ribs to allow access to the outer hull skin. The cut-outs are made leaving a "flange" on either side of the ribs that is then bonded to the hull with overlaid strips of glass as a continuous "tab" on each side of the ribs. The structural grid on the Firsts typically extends about 750 mm (≈30") above the bottom of the hull on either side and is bonded in place with an epoxy adhesive. The grids are/were put in place while the outer hull glass was still "green" (i.e. not fully cured) to allow both a chemical as well as adhesive bond creating a very strong and reasonably stiff hull structure. The hull does flex somewhat in a seaway, however, such that cracking in the gel-coat surface of the grid is not uncommon. It is a cosmetic rather than structural issue. (For a more detailed discussion of the construction method, refer to Ferenc Maté's, "The Worlds Best SAILBOATS" commencing on Page 42.)
Looking at your snaps, I suggest that the interstitial spaces (between the underside of the floor boards and the inner surface of the hull) could use a good cleaning (hot water, Dove dish soap and a [very] little bleach followed with fresh water rinsing) and thereafter routine maintenance. Gel-coat "touch-up" can be applied once the surfaces are cleaned properly if the cracks really bother you. (You can use some color additives to "tint" the touch-up gel-coat to match the original.)
Further, in one of the snaps I noted what appears to be a check-valve in a bilge pump hose, which is unwise. While the valve will prevent back flow into the bilge, it is an obstruction that reduces the pumps discharge rate and can become clogged or otherwise malfunction obviating the purpose of the pump itself.
"It is not so much for its beauty that the sea makes a claim upon men's hearts, as for that subtle something, that quality of air, that emanation from the waves, that so wonderfully renews a weary spirit."