moisture meter

[Sailordave]

SUPPOSEDLY the survey on the boat my club purchased (Catalina 320) last summer said the deck around the chainplates needs attention. I've sounded the decks and they seem fine. (I haven't seen the survey)

I was thinking about going below and drilling VERY SMALL (1/8" or less ) holes into the underside of the deck and sticking a moisture meter into the core.

What say y'all about this idea? And what kind of moisture meter do you recommend?

Never used one for anything so I know nuthin' about em!

Thanks, David

[Jason K]

A moisture meter will work for detecting moisture without drilling. If you are going to drill, then the condition of the core will tell you what you need to know with a visual inspection. Good core will be clean, bright, dry and well bonded.

If the only purpose of the moisture meter would be to inspect this area, I would simply drill. A decent unit is more than $300 and they won't tell you as much as simply drilling, particularly if don't have much experience with them.

When you drill, I would use a larger bit and drill fewer holes. They can easily be filled in with thickened epoxy.

You'll also want to make sure that the chainplates are sufficiently water tight; in addition to sealant at the deck, you'll want to isolate the core (if it's currently exposed).

[Quetzalsailor]

You might inquire of Catalina how they built the boat at the chainplates, stanchion bases and similar areas with planned attachment. I would like to believe that today's manufacturers have got the word. I don't know how old your boat is but some manufacturers stopped the core at such places. Other manufacturers used plywood (for crush resistance), in lieu of softer core and depended upon sealing the edges of the wood with resin at the fastenings. Still others simply depended upon the bedding to keep the core dry. Our '70 NE 38 is solid glass at most of these places (they depended on bedding and the Airex core to not cause a problem elsewhere). Our old '72 Morgan 27 had exposed balsa core at the partners.

If you have balsa or wood core, I would think that one 1/4" hole, neatly drilled near the suspect fitting, would tell you what you need to know. And you could just leave it afterwords.

Those little covers around the chainplates simply conceal an oversize slot for the chainplate. They need to be rebedded, and the slot cleaned out and resealed, at some regular interval. The sages on this list will opine (gotta' do mine!)

[Maine Sail]

The chain plates on my 2005 Catalina 310 were surrounded by aluminum that was laminated into the deck. Catalina does this now for stanchions and other deck hardware areas. A moisture meter may mistake this for moisture..