Join Date: Jul 2008
Location: chesapeake bay
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actually brak a thru does have structure holding, the lip in the mushroom head.
the way to not have to do as much painting is you do the tapering on the inside. the reason for the 12 to one taper is not for looks, there is a real reason.
the idea is the taper evens out the flex that happens, if you were to just plug a hole, then add a bunch of glass over it you would be adding a stronger spot in the hull, any flex that happens will now be concentrated on the edge of the patch, which can cause the glass to flex more right there and break the fibers. a way to show this is get a piece of paper and glue 3 2 inch circles of paper to it all in the center. now roll the paper up, yes this is and exaggeration of the flex but paper will roll up fiber glass will not. when rolled the paper will crease on the edge of the "patch"
the taper also evens out the stress on the now only mechanically bonded patch. yes epoxy only mechanically bonds to the hull. it would be like glueing a quarter to the piece of paper when you tried to roll it up the quarter would pop off. edit maybe a better example would be glueing the quarter to a thin sheet of aluminum, then roll the sheet up
the taper allows the patch to flex with the hull not against it, and it evens the flex between the stronger epoxy vrs the weaker polyester. it is very important in the long run
Last edited by scottyt; 03-01-2009 at 09:54 PM.