posted 03-27-2000 09:37 AM ET (US)
David just about any foam filled hull Whaler or otherwise that is that dated is going to show some moisture no way around it but and that is a big "but" does it make any difference --- my opinion if the hull is sound and no delimitation can be detected using manual techniques, plus as you mentioned the weight is with in spec and most importantly where the hole is you can't detect sponginess in the foam --- I say your "fiberglass" guy is full of beans! Go ahead and do the patch and enjoy. These "Wagner" moisture meters are designed for wood --- yes the high end non-destructive type can read through fiberglass a whooping 1/8 to 1/4 inch max (it can also pick up any slight moisture present in the surface coating)!
What I am saying these units are fine used by someone who understands their original purpose. This adaptation for fiberglass and materials other than wood is questionable at best (even thought they are promoted for these uses)--
Now there are units costing 1000's of dollars available... believe me you aren't going to see these even in a large local shop or yard, they are designed for industrial and research applications, that would tell you down the molecule how much is present.
The unit I bet your local guy used was a Wagner handheld and it beeped like crazy as he moved over the hull --- did he write down the average reading from each area he tested?
What sensitivity level did he set it and did he maintain that as a constant or did he keep messing with it? Then compute out the mean content level --- my guess he didn't!!
I have seen to many times folks get sucked in by this in the last few years as these "non-destructive" type of "wood" moisture meters became relatively affordable to the average shop and even to marine surveyors, even though these users might be well intentions one has to realize the limitations and not jump to unsupported conclusions until all factors are taken into account.
Sorry for the long dissertation, there are a few other folks on the forum which might differ with my opinion and a few others who are pretty good at fiberglass hopefully they will offer their opinions and advice ---
For my two cents, as I mentioned, go ahead get her fixed up and get ready for a summer of fun up in New England.....
Regards, Thomas