Understanding Moisture Readings on a Marine Survey?

[hostage]

I am interested in a boat that is hours away. I was a little surprised, when the broker sent me a Marine Survey of the boat. I tend to be a bit cynical, when it comes to people selling stuff. Though a couple things in the report caught my eye. The surveyor used a Tramex Skipper Plus, though I am having issues interpreting the results as the report seemed to be fairly factual with out much opinion.

2001 Chaparral 230 SSE
Freeboard/Topsides: Well kept, moisture content 20 to 40
Transom: In good condition, moisture content 40 to 55
Bottom: Minor cosmetic deficiencies. Moisture content 30 to 75
Decks: In good condition, moisture content 20 to 25
Internal Structure: In good condition, moisture content 60 to 75
Swim Platform: Extended and integral, all good. Moisture content 30 to 80

Other minor things in the report that the surveyor mentioned needed fix have been addressed. From what I read Moisture Meters readings for the fiberglass are done on a scale, so it doesn't give the actual percentage of moisture, like it does for wood. I also know there can be false positives as these things can read condensation in the bilge or misread fittings, etc on the other side of the hull. From what I am reading here, it looks like that the transom is going to be solid, though I am not fully sure what to think about the bottom of the boat and the transom. Is this boat more likely to have blisters. I am also really curious why an extended swim platform would have such a high moisture content.

For people who understand this information, what are your thoughts?

 

[JustJason]

Was your surveyor a SAMS guy?

I use a moisture meter, but I don't list readings like that. Moisture meters give comparable readings, from 1 spot to the next spot, and from 1 brand of meter to the next meter. The numbers 20 or 40 or 80 don't even really mean anything.

20 Compared to what?

40 Compared to what?

80 Compared to what?

See what I mean?

I personally use a GRP33+ as my main and a GE protimeter as my back up.

When I write my reports, I simply state that my comparable moisture meter readings are either negligible, elevated, or excessive.

Getting into numbers is useless.

Unless there are other observations, such as poor percussion test results, blistering in paint or gel coat, swelling, panting, cracking etc what really matters is the integrity of the FRP bond.

Wood cored boats are always going to read some moisture. Wood lignin's are always moist, it's what gives wood strength. If the wood didn't have any moisture at all in it, it wouldn't be wood, it would be sawdust. So the next question is how moist is too moist? The answer is if the hull percussion tests well and there are no other secondary observations, then the wood is good enough for now. If the wood was to moist, there would be bonding issues.

Composites should be dry, but even if they have elevated moisture levels, that doesn't necessarily mean the bonding is bad.

Other issues with moisture meters are was it used on a short haul, or has the boat been out of the water for a month. What is the relative humidity outside? Is the meter calibrated, and if so, against what? I like my GRP33+ because I have the calibration plates and can calibrate it in the field if I need to.

The biggest question is how does your surveyor feel about the boat? Does he feel that, where accessible, the FRP bonding is good. Or is he finding soft spots, disbonding, delamination, pulled tabbing, or other secondary observations?

 

[tpenfield]

Readings above 35-40% are high, but the information provided (by the surveyor) is so general to the point of not being useful.

It seems like a 'wet' boat, but without specifics, you don't know if it is isolated or wide-spread.

 

[hostage]

Was your surveyor a SAMS guy?

I use a moisture meter, but I don't list readings like that. Moisture meters give comparable readings, from 1 spot to the next spot, and from 1 brand of meter to the next meter. The numbers 20 or 40 or 80 don't even really mean anything.

20 Compared to what?

40 Compared to what?

80 Compared to what?

See what I mean?

I personally use a GRP33+ as my main and a GE protimeter as my back up.

When I write my reports, I simply state that my comparable moisture meter readings are either negligible, elevated, or excessive.

Getting into numbers is useless.

Unless there are other observations, such as poor percussion test results, blistering in paint or gel coat, swelling, panting, cracking etc what really matters is the integrity of the FRP bond.

Wood cored boats are always going to read some moisture. Wood lignin's are always moist, it's what gives wood strength. If the wood didn't have any moisture at all in it, it wouldn't be wood, it would be sawdust. So the next question is how moist is too moist? The answer is if the hull percussion tests well and there are no other secondary observations, then the wood is good enough for now. If the wood was to moist, there would be bonding issues.

Composites should be dry, but even if they have elevated moisture levels, that doesn't necessarily mean the bonding is bad.

Other issues with moisture meters are was it used on a short haul, or has the boat been out of the water for a month. What is the relative humidity outside? Is the meter calibrated, and if so, against what? I like my GRP33+ because I have the calibration plates and can calibrate it in the field if I need to.

The biggest question is how does your surveyor feel about the boat? Does he feel that, where accessible, the FRP bonding is good. Or is he finding soft spots, disbonding, delamination, pulled tabbing, or other secondary observations?

He had all of these under his name on the report:
Marine Investigator
Lloyd’s Approved Surveyor
Accredited Marine Surveyor,
Certified Marine Surveyor, ACMS-CMS-0245
ABYC Certified Master Marine Technician
Transport Canada Appointed Tonnage Measurer
Transport Canada Approved Commercial vessel consultant
ABYC, IAMI, OMOA, RINA

The comparison is what was bugging me a scale could be 1 mile or a million. He took a bunch of pictures of him holding up the moisture meter to the hull showing the readings. The only negative thing he noted on the hull was "Minor cosmetic deficiencies". Based off the boating season and the early spring survey, I think it has been out of the water for months. The survey was conducted in April of 2021, so it was over a year ago and I wasn't there for it. I emailed the surveyor a couple hours ago asking for his interpetitation and asked him would he recommend the boat to a friend. I am eagerly waiting for his reply, though was wondering if he doesn't get back to me or if it takes a while, would anyone understand what he listed in the report.

 

[QBhoy]

Fairly high readings on the hull, for sure. Anything over 45 is considered needing attention and water has ingressed for certain. 30-45 even, is likely needing attention.
Ideally less than 20 is considered fairly good.

 

[dingbat]

If all else fails.......read the manual

Sensor reads 0 to 30% moisture content.
GRP readings are noted in percent of those levels.
A GRP reading of 50 = 15% moisture

Compensation values for readings taken at various humidity (air) level are also given

https://tramexmeters.com/perch/resources/downloads/user-guides/skipper-plus-user-guide.pdf

 

[hostage]

but the information provided (by the surveyor) is so general to the point of not being useful.

If all else fails.......read the manual

Sensor reads 0 to 30% moisture content.
GRP readings are noted in percent of those levels.
A GRP reading of 50 = 15% moisture

Compensation values for readings taken at various humidity (air) level are also given

https://tramexmeters.com/perch/resources/downloads/user-guides/skipper-plus-user-guide.pdf

Where do you see GRP reading of 50 = 15% moisture. I looked over the manual twice, then searched 50 and 15%. Didn't see this anywhere in the manual.

 

[mr 88]

I would be very surprised if the hull itself ( not the transom ) along with the topsides is cored as in it should be solid glass. Sometimes the gunwales are cored where fishing gear gets installed that's about it. So how is he coming up with moisture content at all in those areas ?

 

[hostage]

I would be very surprised if the hull itself ( not the transom ) along with the topsides is cored as in it should be solid glass. Sometimes the gunwales are cored where fishing gear gets installed that's about it. So how is he coming up with moisture content at all in those areas ?

I have no idea sent him an email asking him some more info as the survey was done over a year ago and I am only looking at this boat now. I think the boat has floatation foam, if that is wet, then maybe that it is where it came from? It could also be that the numbers are fine and I don't understand the context.

 

[JustJason]

He had all of these under his name on the report:
Marine Investigator
Lloyd’s Approved Surveyor
Accredited Marine Surveyor,
Certified Marine Surveyor, ACMS-CMS-0245
ABYC Certified Master Marine Technician
Transport Canada Appointed Tonnage Measurer
Transport Canada Approved Commercial vessel consultant
ABYC, IAMI, OMOA, RINA

The comparison is what was bugging me a scale could be 1 mile or a million. He took a bunch of pictures of him holding up the moisture meter to the hull showing the readings. The only negative thing he noted on the hull was "Minor cosmetic deficiencies". Based off the boating season and the early spring survey, I think it has been out of the water for months. The survey was conducted in April of 2021, so it was over a year ago and I wasn't there for it. I emailed the surveyor a couple hours ago asking for his interpetitation and asked him would he recommend the boat to a friend. I am eagerly waiting for his reply, though was wondering if he doesn't get back to me or if it takes a while, would anyone understand what he listed in the report.

I'm a SAMS guy, I can tell you ACMS is a mail order organization, they do not have the reputation of SAMS or NAMS.

"ABYC Certified Master Marine Technician"

I am also an ABYC Certified Master Tech, there are NOT that many of us. If you want to PM me this person's name, I will be happy to check the roster and tell you which cert's he actually has with ABYC.

At the end of the day it comes down to would your surveyor recommend their father/mother/brother/sister buy this boat or not. If your surveyor did his job there will be deficiencies in his report, there always are. Those deficiencies will always effect FMV. He should have given you an appraised value on the boat taking into account book values, actual sold values of the same or similar vessels, and a condition statement. We can exchange info via PM and I'll be happy to take a look at the report over the weekend.

Another thing to keep in mind is that different boat builders use different additives in the resins. Some additives are metallic and will fool moisture meters. Some boats will always read 10%, 20%, 50% 100% wet, as a baseline, not including actual moisture content, no matter what due to resin additives and other factors. One moisture meter will NEVER read the same as another moisture meter. A SAMS member did one of the best write up's I've ever seen on using and interpreting moisture meters, I would give this a read - http://www.pcmarinesurveys.com/Moisture meter mythology.htm

Another thing to keep in mind is intended service life. Your average pleasure boat has a 20 to 25 year average service life depending on what you want to read. A 2001 pleasure boat is near the end of it's intended service life. At the same time, condition and care is everything. I have surveyed boats built in the 1990's that were always indoor kept and in amazing condition, and I have surveyed boats that are just a couple of years old, and they are basket cases. It all depends on how it was cared for and kept. I live in work in FL, as a general rule, I do not survey boats older than 20 years old, as I know what the end result is very likely going to be. I will make exceptions to that rule on a case by case basis.

 

[dingbat]

Where do you see GRP reading of 50 = 15% moisture. I looked over the manual twice, then searched 50 and 15%. Didn't see this anywhere in the manual.

“The term reference scale is used for a moisture meter reading mode wherein the meter takes qualitative readings as opposed to quantitative readings. These readings are shown as a numerical value which the user can then use to estimate whether that material is “wet” or “dry.”
It is important to note that the numbers used in a reference scale are not indicative of a specific percentage of moisture content. Instead, reading results in the reference scale are used as a relative indication of how much moisture a material has in it.

For example, say you have two different moisture meters. One meter might have a reference scale setting that displays moisture values from 0-300, while the other one goes from 0-100. While it might be tempting to think of readings on the 0-100 reference scale meter as percent values, they are not. A reading of 12 on a 0-100 scale does not mean that the material has 12% MC, it just indicates that the moisture content is relatively low.”

http://www.moisturemetersdelmhorst.com/content/moisturemetersdelmhorst/EN/images/Moisture-Meter-Reference-Scale.pdf