How to assess core dampness/damage

[wexcellent]

We purchased 2002 22' cruiser. As far as I can tell the boat has never had any repairs done in terms of correcting factory penetrations into the balsa core. As far as I know the boat was always stored under a cover until this last winter and was used lightly.

Before purchasing the boat I had no experience with C-Dory's or with fiberglass boats. I had intended to have a survey done but circumstances were such with the seller that it was impractical if not impossible.

I finally got hold of a moisture meter and checked around the screws holding the gas tank cleats. The meter shows elevated moisture the closer I move to the screw holes closest to the center line of the boat. I also checked the transom and find elevated moisture on the right side of the main motor mounts, but not lower.

I have several basic questions and please forgive me if they have been answered elsewhere on the site and I didn't find it:

How do I determine how bad the problem is short of opening things up? My Protimeter Surveymaster moisture meter only gives me a relative moisture reading when I hold it over the fiberglass. To get an actual moisture percentage I would need to drill a secondary hole next to the screw hole. Am I trying to just tap on the floor (and I guess on the hull under the area too?) and determine if there is delamination between the balsa and fiberglass, which I assume would necessitate replacement of core material? If I don't detect any or much hollow sound, is just doing the standard oversizing the hole and epoxying an option and if so is there a practical way to try and dry out the exposed core in the hole first? How do I know how dry it needs to be before just covering it up?

For the transom repair it seems I am going to need to remove the main engine, check the mounting holes, and while I am at it clean out and epoxy where the transom drain hole is. Again though, if I dig out any soft core how dry does the surrounding area need to be and how do I dry it out?

Again, sorry if some of these questions are redundant. I see a lot of info about fixing these things but I can't seem to find specific advice about making these kinds of judgment calls.

Thanks! Steve

[clayhubler]

Steve,
Sounds like you may have a little moisture in there but no reason to panic. I believe that probably about 90% of the boats have some wet core but only about 1% of those will ever experience any kind of failure or soft spot because of it. That’s just my opinion. My boat had a lot of wet and rotten core, but still it had no soft spots anywhere. The boats are tough. Look through my album, your boat is almost the same year, so construction should be similar. I think if I was in your shoes, I would pull the screws around the gas tanks, dry it out as good as you can, put in some epoxy plugs and call it good. I can look at the boat if you want.

[thataway]

Agree with clayhubler and great that he has offered to help you.

I would be sounding out these areas, and drilling small test holes. You can tell if the "shavings from the core are wet or dry.

You first need to map out the cockpit floor area, where it sounds "dull" or suggests delam or water in the core. Also use the relative scales on the moisture meter --good that you have a boat meter, rather than one of the big box type (although these can be used for relative readings.

One factor is proximity to metals. This is probably more important on the transom. You do want to attack all of these areas.

Drying it out--that is a bit of a problem. Hard to do with really saturated core--if not impossible. Removing the tanks, redoing this area is probably going to be best If there is extensive damage.

Alcohol can help to dry out areas, and forced hot air, as well as careful use of heat lamps etc--but again for extensive damage the tanks should come out, for safety if nothing else.

Minimal amount of damage, and if if you can definitively outline where the damage is--infusion of epoxy may be enough. Certainly spot repair, sealing off the penetrations (engine bolt holes) or other transom penetration is going to be necessary.

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