Well, I began exploring the extent of rot within the hull of my 1970 18 foot yesterday (While I can't confirm it's a 1970, that's what the previous owner told me, and given it has no stringer floor, or serial number that I could find, I tend to think that's right). At any rate, both layers of core that run most of the the length of the hull in the floor on both sides, appear water logged. I cut an inspection hole under the driver seat area to confirm it is soaked (pulled out the mush), and the next layer under the next fibergalss skin under that seemed soggy when I drilled into it. I'll try to post some pics tonight. My biggest concern at this point is not the work involved, but rather the availability of replacement core. I believe they would consist of 4 long balsa boards (2 stacked on each side) - can anyone confirm that, as well as suggest where replacements might be found? Note my preference here would be balsa as opposed to composite, as the boat will be kept dry in the future, so I'm not really concerned about future rot. All advise welcome.
I have never done it, but I would be tempted to use single layer end grain like the later boats. It is readily available. You will need to accurately support the hull before removing the core. jim
Thanks Jim, good point on supporting the hull. I think I'll rig up a multi bunked trailer to support the bottom contour before I continue. Any comments on how to cut them out? My initial hole (see attached photo) was done with an angle grinder, but I'm thinking a recip saw laid on its side with a long blade might be a better choice (less likely to breach the hull) when I get to exposing the whole length of balsa core?
There are posts on this forum with pictures. I think the subject was a 16 or 17 ft runabout. I would try just cutting the glass layer with a die grinder or similar shallow cutter. If you leave the deck on while doing the core, it will help hold the shape. jim
