Frozen Fiberglass - Survey Issue?

Jan 2, 2017
765
O'Day & Islander 322 & 37 Scottsdale, AZ & Owls Head, ME
A friend of mine is considering purchasing a Catalina 42 on the hard in Hull, MA.
The surveyor says he “can't test the fiberglass if it's frozen”. (I assume he means test for moisture content.)
I've never heard of that. Mirage was tested when it was 20 degrees. No problem.
Has anyone run into this? Does the surveyor know what he’s talking about?
 
Sep 25, 2008
7,075
Alden 50 Sarasota, Florida
He can’t reliably sound the hull (banging on it with a phenolic hammer) except to listen for voids but a capacitance tester (moisture meter) should be uneffected by frozen water.
 

Ward H

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Nov 7, 2011
3,645
Catalina 30 Mk II Barnegat, NJ
Understanding Moisture Meters is a good article by Maine Sail on moisture meters.
I copied this paragraph from Rod's article

"Moisture meters can not read frozen water. There is no benefit in even bringing your meter to a boat in the dead of winter. Along those same lines if a surveyor says he can survey a boat for you at 20 degrees F and get moisture readings walk away. Temps should be well above freezing, for a while, before even considering moisture readings."

I'm guessing both reasons, @Don S/V ILLusion's and Maine Sail's are correct. Makes sense that a soft deck due to wet wood would be a hard deck at 20 degrees.
 
Oct 6, 2007
1,023
Hunter H30 1982 Chicago IL
I ran into this issue last year when I needed a survey for insurance. Had to wait until early April for above freezing temperatures for moisture readings and sounding. I also didn’t want to remove the shrink wrap before spring.
 
Jan 2, 2017
765
O'Day & Islander 322 & 37 Scottsdale, AZ & Owls Head, ME
The Can You Trust Them article cites somewhat contradictory findings:

“Frozen water. We ran two different tests to determine whether the meters could detect frozen water. In the first, we compared a sample of .135″ laminate and wet paper frozen. No meter gave a reading differing from laminate alone. This suggested that the meters do not detect frozen water.
In the second set of tests, we took four panels in various stages of wetness and deterioration: moist, saturated, advanced brown rot and white rot. Reading were taken wet. Then the panels were frozen and tested again. Comparing the wet and frozen readings, most of the frozen readings were lower than the wet, but not all. We cannot account for those few frozen readings that were the same as room temperature readings or higher.
While the tests werent the same, the discrepancies leave questions. Still, the bottom line is not to trust any moisture meter readings taken when the laminate is below 32F. Wait until the temperature warms and the laminate has thawed.
As a side note, glycol, a byproduct of the resins used in boats and the cause of some blistering, will not freeze and can be detected in sub-freezing weather.”

Moisture meters are used in lumber yards that are not heated. I found this quote to be interesting:

Once the wood is under 30% MC, a moisture meter starts to work and works down to 6% MC or so. At this moisture, the only water in wood is called bound water and is not a liquid. So, it cannot freeze. So, you can use a meter on wood that is under 32 F and achieve good readings.

So, if the water in the balsa core is bound water, the moisture meter (maybe with an adjustment) should work?
 
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Jan 19, 2010
12,362
Hobie 16 & Rhodes 22 Skeeter Charleston
The Can You Trust Them article cites somewhat contradictory findings:

“Frozen water. We ran two different tests to determine whether the meters could detect frozen water. In the first, we compared a sample of .135″ laminate and wet paper frozen. No meter gave a reading differing from laminate alone. This suggested that the meters do not detect frozen water.
In the second set of tests, we took four panels in various stages of wetness and deterioration: moist, saturated, advanced brown rot and white rot. Reading were taken wet. Then the panels were frozen and tested again. Comparing the wet and frozen readings, most of the frozen readings were lower than the wet, but not all. We cannot account for those few frozen readings that were the same as room temperature readings or higher.
While the tests werent the same, the discrepancies leave questions. Still, the bottom line is not to trust any moisture meter readings taken when the laminate is below 32F. Wait until the temperature warms and the laminate has thawed.
As a side note, glycol, a byproduct of the resins used in boats and the cause of some blistering, will not freeze and can be detected in sub-freezing weather.”

Moisture meters are used in lumber yards that are not heated. I found this quote to be interesting:

Once the wood is under 30% MC, a moisture meter starts to work and works down to 6% MC or so. At this moisture, the only water in wood is called bound water and is not a liquid. So, it cannot freeze. So, you can use a meter on wood that is under 32 F and achieve good readings.

So, if the water in the balsa core is bound water, the moisture meter (maybe with an adjustment) should work?
I'm not sure "bound water" is relevant. Wood is a cellulose (a sugar polymer). It can be represented like this

1642639115182.png
where "n" means each unit is bound to another identical unit as the chain grows longer and longer. Water can be "split" across the OH and O groups in the ring... by a mechanism called "hydrogen bonding". something like this... (see red circles for a "bound water").

1642639280337.png


The oxygen atom in water nearly strips the hydrogen of its electron that is shared in the bond... however, the neighboring oxygen atom has an orbital that sticks out into space and the "naked" hydrogen grabs onto those electrons... Hydrogen bonding is what holds the cellulose chains together... it is also what allows wood to "heal" from repeated flexing. You should not think of bound water as water intrusion. It is part of the wood. Wood that has had its bound water stripped will be very brittle and will check easily.
 
Mar 26, 2011
3,399
Corsair F-24 MK I Deale, MD
A friend of mine is considering purchasing a Catalina 42 on the hard in Hull, MA.
The surveyor says he “can't test the fiberglass if it's frozen”. (I assume he means test for moisture content.)
I've never heard of that. Mirage was tested when it was 20 degrees. No problem.
Has anyone run into this? Does the surveyor know what he’s talking about?
Sounds like...
a. The meter results are at least significantly effected by freezing. Sounding certainly is. The accuracy will be degraded AND if there is an error (bad deck he missed) you will not have any legal standing.
b. No, you really didn't get an inspection on "Mirage." It is fairly common for inspections to include things that were not actually inspected. If he didn't mention this problem, I would not use him again.

The marine business is tough in the winter. You can't inspect properly. You can't work outside with most materials unless the high is nearly 60 (because it is colder at night and the product will be curing at night). So they push it.
 
Jan 2, 2017
765
O'Day & Islander 322 & 37 Scottsdale, AZ & Owls Head, ME
My surveyor took extensive meter readings on Mirage with a Tramex moisture meter. Temperatures appear to have varied from 20 degrees to 35. I have no reason to believe that he was anything but professional and find it hard to believe that he made up all those readings.
 
Sep 25, 2008
7,075
Alden 50 Sarasota, Florida
My surveyor took extensive meter readings on Mirage with a Tramex moisture meter. Temperatures appear to have varied from 20 degrees to 35. I have no reason to believe that he was anything but professional and find it hard to believe that he made up all those readings.
I doubt he “made up” what the meter indicated. I do doubt the validity of whatever results he reported. Some capacitance meters can be pretty precise with entrained water which is frozen but most are about as useful as a weegee board.
 
Mar 26, 2011
3,399
Corsair F-24 MK I Deale, MD
My surveyor took extensive meter readings on Mirage with a Tramex moisture meter. Temperatures appear to have varied from 20 degrees to 35. I have no reason to believe that he was anything but professional and find it hard to believe that he made up all those readings.
How would you tap-test a deck if it was saturated and frozen? You cannot. It is also accepted fact that frozen water reads, at the very least, quite differently, so ...

... perhaps he simply was not knowledgeable regarding this instrument shortcoming. The rest is opinion and guesswork. But if it was below freezing the night before, he should have at least disclosed that the readings could be meaningless. I do inspections in refineries, and I owten note things that could not be properly inspected for some reason. There are things you simply cannot inspect in all weather conditions.
 
Jan 2, 2017
765
O'Day & Islander 322 & 37 Scottsdale, AZ & Owls Head, ME
My surveyor seems to be taking some serious heat here. Too bad he’s not here to defend himself.
 
Oct 22, 2014
20,989
CAL 35 Cruiser #21 moored EVERETT WA
My surveyor took extensive meter readings on Mirage with a Tramex moisture meter.
Reading the product specs and features the Tramex sounds like a cool tool to use for non invasive testing of material moisture content. It uses a differential analysis of moisture electrical conductivity in materials.

While a special tool it still is limited by science.

Ice functions as an electrical insulator.

So does ice conduct electricity? No, ice does not conduct electricity because it does not have free mobile ions to freely flow through it to conduct electricity. Ice is a crystalline form of water due to which the ionic mobility in ice is pretty low making it an insulator.

If the temps were below freezing when the inspection occurred then it is not likely that moisture readings of your boat were accurate.
 
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