Zygote is scheduled to today be re-launched, after more weeks than I want to remember of yard work. We had the bulwarks, cover board, and taff rail sprayed with Alexseal. And the rudder cheeks and boomkin coated with an 6-coating system from Milux, which is apparently only sold to professionals.
The manager of Scarborough Marina kindly lent me a moisture meter to run over the hull (after what we’ll call 4 weeks of being on the hard). Other than yard work, Zygote has been in tropical or sub-tropical waters for all except a few weeks of its 11 years.
The hull, which had a coat of vinylester before leaving the Sam L Morse Co yard, registered at 0% (or less than 5% - the needle of the instrument did not move) all over except for one patch about the size of my hand, about 20 cm vertically below the prop shaft/cutless bearing on starboard. That patch read 7 - 9% moisture. No detectable moisture on port side. My guess is some water enters the hull beside the cutless bearing but does not travel far.
The rudder, which is GRP, registered an even 17% moisture. I don’t know how Zygote’s rudder was constructed - I’m guessing it has a wooden core or a foam core, probably the latter. No blisters in the gelcoat.
Zygote has a Freehand self-steering trim tab aft of the rudder. The trim tab is teak. About 6 years ago, while we were still in South-east Asia, I noticed some worm in the teak. So I ordered a new trim tab from Mike Anderson but, before it arrived, I had a yard in Singapore coat the old trim tab with a high density epoxy. The trim tab was no doubt moist when it was clad in epoxy. And the trim tab reads maximum moisture (25% or greater)!
I had the moisture meter set to read surface moisture.
I’ve no time to do anything about the water in the hull today (a reading of 7 - 9% is acceptable according to some), but I will think about whether there’s a way to stop more water entering via the same route. Your suggestions are welcome. Douglas? anyone with hull moisture figures?