Just how bad is a moisture reading of 23?

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Jcorstorphine

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I have been looking at yet another project boat but the survey indicates 23 on a Sovereign Moisture meter which has a full scale dflection of 25! The boat has been in the water continuously for a number of years but has been epoxy treated. These were no signs of blistering.

Any thoughts?

John
 
Moisture readings

pcatterall said:
23 in how many places?
what are the readings above the water line?
High moisture readings do not mean osmoisis is present. How long ago was she epoxied? if, say, a few years and no blisters then there is room for optimism.
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Thanks for your reply. Readings above the water line were 15 to 19 and I have to assume that the 23 reading was the highest below the water line as the survey quotes "a number of readings" The epoxy treatment must have been carried out over 5 years ago as present owner has not done anything to the boat over the five years he has owned it other than let it fall into neglect.

John
 
Even if it is osmosis its no big deal. Boats don't sink because of it. The big deal is companies hyping it up to make money.
 
If the readings are 15-19 above the water line I'd say that the readings of 23 below the water line are a serious indication that the moisture meter you are using is in serious need of calibration and nothing more.

Wander over to a few other boats and test above and below the waterline on them. If you can find a 1 or 2 year old modern AWB to use as a reference you may either end up condemning every bot in the yard .......... or throwing away the meter :)

Whenever someone waves a moisture meter about I use this tactic to question their 'readings'. Works especially well if their own boat suddenly becomes a pox ridden heap. :)
 
Moisture content

The whole problem with moisture content is the fact that the boat is wet when it is hauled out of the water for the survey, pressure washed and then scraped in a few places. We never used to worry about moisture content of wooden boats, in fact we relied on it to swell the planks. As one poster said, boat dont sink from Osmosis. If I go ahead with buying the boat, the plan would be to get the hull blasted to remove all the antifouling and let it sit for a year while I do the refurb then take a rain check at 6 month with another measuremnet to see if I should blast off the epoxy.

Thanks to all.

any other comments welcome.
 
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Jcorstorphine said:
I have been looking at yet another project boat but the survey indicates 23 on a Sovereign Moisture meter which has a full scale dflection of 25! The boat has been in the water continuously for a number of years but has been epoxy treated. These were no signs of blistering.

Any thoughts?

John
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John,

I assume the readings quoted by your surveyors are Scale A and %H2O. Readings of around 10%H2O are regarded as normal, so yes the reading are high, but so many factors should be considered and moisture readings alone are simply inadequate. Did you surveyor not elaborate on the readings, their significance and interpretation?

I would also say reading of 15-19 for above water line baseline measurements are also very high and this as a surveyor would give me concern to check my meter's calibration and to test on other vessels as a comparison. Can I suggest you go back to your surveyor and ask for him to clarify further his results and provide guidance.
 
Jcorstorphine said:
The whole problem with moisture content is the fact that the boat is wet when it is hauled out of the water for the survey, pressure washed and then scraped in a few places. We never used to worry about moisture content of wooden boats, in fact we relied on it to swell the planks. As one poster said, boat dont sink from Osmosis. If I go ahead with buying the boat, the plan would be to get the hull blasted to remove all the antifouling and let it sit for a year while I do the refurb then take a rain check at 6 month with another measuremnet to see if I should blast off the epoxy.

Thanks to all.

any other comments welcome.
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You're very patient - I expect to pay on Friday and sail on Saturday!
 
Cant ask surveyor.

minkysailing said:
John,

I assume the readings quoted by your surveyors are Scale A and %H2O. Readings of around 10%H2O are regarded as normal, so yes the reading are high, but so many factors should be considered and moisture readings alone are simply inadequate. Did you surveyor not elaborate on the readings, their significance and interpretation?

I would also say reading of 15-19 for above water line baseline measurements are also very high and this as a surveyor would give me concern to check my meter's calibration and to test on other vessels as a comparison. Can I suggest you go back to your surveyor and ask for him to clarify further his results and provide guidance.
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Difficult situation as the survey was not commissioned by me so I have no access to him. The survey was actually commissioned by a third party last year who did not proceed. It does mention that the moisture level may drop if the boat is hauled out and stored ashore but also indicates that the epoxy may have been applied before the boat has dried out.

I should say this is a project boat and is on the market at approx 1/3 to ¼ of a similar boat in good condition. Its actually a Macwester Wight ketch.

The plan was to get it out of the water, carry out a refurb and get a full survey prior to putting it back in commission but I am just a wee bit concerned over the moisture. Problem is, I am in a bit of a race as there is someone else coming to see it very soon and I have to make my mind up tonight.
 
Jcorstorphine said:
I have been looking at yet another project boat but the survey indicates 23 on a Sovereign Moisture meter which has a full scale dflection of 25! The boat has been in the water continuously for a number of years but has been epoxy treated. These were no signs of blistering.

Any thoughts?

John
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A couple of years back i had my Halberdier hauled out for a complete topside 2 pack repaint. The moisture content was around 20 in various points on the hull and as such far to wet to paint with 2 pack ( it really needs to be below 10 on the Sov scale).

The point is that we left her to 'dry' for about 8 months before giving up as it had only dried a couple of 'points'. In the end to get her to dry sufficiently I had her bottom pealed and that released the moisture from the laminate in a further couple of months.

Obviously I could have had her force dried with heaters etc. but in the end after looking at the costs went for stripping and a nice new epoxy bottom as a bonus.

The point I'm making is that GRP boats, particularly old ones like a MW Wight with thick layup will take a hell of a long time to 'dry out'. And as others have said ... does it really matter?

All best Nick
 
As most posters say, the callibration of the instrument may be out. The difference above and below wl are not so great. If it was epoxied 5 years ago and there are no blisters then this would give me a bit of confidence.
I surveyed my own hull at 1 foot centers, there were some interesting readings but all were relatable to internal features such as tanks etc.
I repeated the survey after epoxying, after priming and again after antifoul, there was little difference in the sets of readings.
 
John - I can offer you my expeience having gone down a route with many similarities to the situation you describe.
8 years ago I bought a project boat in very poor condition. She'd been epoxied from new but afloat for over 20 years in the Med. and had been shipped back to Scotland for sale - I think because she was a trade-in.
The survey had been commisioned by the selling broker and hull moisture readings were off the scale, plus light blistering all over in our case. The already very low price set before the survey was then reduced by 50% so were down to the 1/3 or 1/4 price that you mention.

It took me 2 years of hard work to refit her, but the one area I didn't much bother with was the hull. I decided to just accept that I have a wet hull, ground out and filled a few obvious blisters, and away we went.

6 or 7 sailing seasons down the line (ashore winters, though in Argyll that''s not much dryer than being afloat..) and I can find no further deteriation at all.

Given the thickness of the hull and the solid basic construction, not unlike a Macwester I would have thought, I don't think I'll need to worry about the osmosis in the next 20 years, which will see my sailing out. Then she can go in the bin!

I think a common error with a really wet hull is to think that you're going to be able to fix it. Just ignore it, enjoy the sailing and the smug satisfaction of knowing how little your boat cost you.
 
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Epoxy treated and high readings .There is no way a surveyor would scrape through the epoxy to take accurate readings. Has the surveyor re epoxied where he has taken the scrapings .:rolleyes:
 
Crabman said:
Epoxy treated and high readings .There is no way a surveyor would scrape through the epoxy to take accurate readings. Has the surveyor re epoxied where he has taken the scrapings .:rolleyes:
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I don't think it would be necessary to scrape off the epoxy in order to get an accurate reading - after all, GRP is just epoxy loaded with glass fibres. Surveyors do scrape off some anti-fouling to get at the hull for examination and readings - I assume that the chemicals in the anti-fouling interfere with the meters.
 
Yes I had a similar question earlier this year. My boat in water for a number of years. When questioned closer the surveyor admitted that the meter was no reliable if copper antifoul was used.... my antifoul was copper based and 48% solids.

So the meter depends on conductivity, hence if the antifoul is conductive the meter reading is useless.
 
Well, after some sleepless nights I decided not to buy the boat in question. It was actually a 1973 Macwester Wight Ketch and on the market at £7,000 but the owner would have accepted £5,500. It did require an excessive amount of TLC but was basically a sound boat.

The final decision was not down to the water content but the shear amount of work required to get the inside up to SWMBO’s standard. The boat reeked of damp and diesel and needed a full internal refurbishment. You could actually smell the interior of the boat from the pontoon before you even put foot on the boat.

It seemed the right decision at the time but a week later I am now regretting my decision not to go ahead.
 
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