Survey - Moisture Content

Athene V30

Athene V30

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Just having a survey at the moment and topsides moisture readings are coming out at 25 (scale 5 to 30), relative humidity 73%, boat next door reading 15.

It is not all over - the transom is quite dry! Boat has been out of water for a year. No blister signs of osmosis.

Don't know what to do now! Go for a reduced price and see if needs to be treated in years to come or walk away? /forums/images/graemlins/frown.gif
 
Peter, a genuine option on a heavy layup boat like yours is to do nothing, especially topsides.
I assume that the topsides are not foam or balsa core, but may be epoxy coated wood?
Have a read of the decent article below


http://www.yachtsnet.co.uk/osmosis.htm



Here is a couple of links to the Sovereign Moisture meter use. Of course he may have used a tramex, but the principle is the same.

www.passionforpaint.co.uk/products/sovereignmeter.pdf

www.bluestarsurveys.co.uk/sovguide.pdf


I would have a look at the structure under the headlinings (pain I know) and jump up and down everywhere loooking for flexing. Also go over the whole deck looking for soft spots. My nose tells me you won't find any. Seek out any cracking from above or below and squeeze the area. If you get moisture back out, then you have trouble. I also doubt you will find this either.

I am in Burnham tomorrow morning, do you want me to go and have a prod?
 
mmmmm I have to say my first instinct is to say walk away and be glad it came up in the survey. If it has been out the water that long then you would expect it to be on the dry side of damp, but it seems not to be. That saying of why buy someone else's problem springs to mind especially the way the market is. Having said that however, did the surveyor give a likely cause why the topsides were so relatively wet / easy fix etc etc ??
 
Alan,
with respect, water passes through each and every GRP moulding EVER made, as water molecules are small enough to pass through any known GRP or epoxy structure.
Moisture readings are a measure of the carbon content between the 2 probes which gives a measure of conductivity, which is thus translated in to a scale of moisture content. If the deck has been painted, that could also give a high reading. Try it on a glass surface, you would be amazed.

Remember, ther is not, so far as I am aware, any reported incidence of a boat sinking or ripping itself apart due to osmosis.

It is, however, a decent bargaining chip.

Peter, I will go over at 9am tomorrow. Mercury later .....
 
Just spoken to the surveyor again (he was very patient with me!) and despite the high readings it doesn't necessarily mean too much trouble. Hitting the hull with a hammer hasn't shown up any problems / delamination etc.

No apparent crazing.

Internally the lockers are wood lined so maybe that is having an impact.

We continue with the survey!
 
Jim,
No problem at all. Already pm'd Peter warning to take my comments as my personal thoughts only as others (like yourself) are far more experienced than I in matters such as this. Cheers,
Alan
 
Having sold a flat where the buyer's surveyor claimed the basement walls had high moisture content, without checking what was behind the wallpaper (aluminium foil) I have learned that the the value of the numbers on the meter alone is not enough.

Have the topsides been painted with something that is conductive? Copper anitfouling comes to mind, but that would be an odd place to have it.
 
areas near water / fuel tanks give higher readings.
GRP is one of the best materials to build boats from /forums/images/graemlins/wink.gif
Just dont put it in the water /forums/images/graemlins/laugh.gif /forums/images/graemlins/laugh.gif /forums/images/graemlins/laugh.gif
 
Peter

If you want a second opinion PM dombuckley of this parish.
in the survey he has carried out on Sirenia he set out the moisture very well and had a mathematical calculation of the proof.
He uses a Tramax meter.
The concern is that a high moisture content could cause a breakdown of the matrix of the GRP.
He concluded that Sirenia was o.k.

He is East Anglia Yacht Surveys.
 
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