need help understanding coring issue

Don't know much about the specifics of moisture testing- but I've read that there's a lot of experience and training required in order to properly use the equipment and interpret the readings. Just an FYI before you purchase a moisture meter...
 
if i had a boat with a cored bottom, you'd be damn sure i'd buy a moisture meter and learn how to use it, if nothing else, as a screening device. with all the money we spend on these floating money pits, what's another $600 bucks? it's a one-time insurance policy. if you find something that MIGHT be a problem area, you contact an expert for a definitive diagnosis and repair, before it gets out of hand.
 
If you are in the market for a good moisture meter, check out the Electrophysics GRP33 (www.jroverseas.com). I used it to do a preliminary check on every potential boat last fall and although I am not trained with it, you gain enough familiarity to recognize a problem boat. When I finally did make my decision and had the boat professionally surveyed, guess what moisture meter the surveyor had? Yup.
 
Maybe it was just me but i clicked on the link in the post (#23) above and it sent my antivirus software into a tizzy with warnings. i'm guessing it's something on that linked website but i just wanted to warn folks. i also reported it to the moderators. let the clicker beware!
 
One point of advice on surveying boats cored below waterline. Unless the boat has been hauled long enough for bottom paint to fully dry, moisure in the paint will peg the meter rendering it virually useless for evaluating bottom core condition.

Good surveyers will use the old-fashined rubber mallet and manually examine at all hardware and through hull locations.
 
Guys,

The website that I provided was right off the moisture meter. I tried it and was able to easily find the GRP33. I believe the price is $325.00 from that outfit. I am sorry that you had problems with that connection.

The odd thing about the meter is that they are made in Mississauga, Ontario, just down the road from us but I had to order it through the U.S. because I could not find a local distributor.
 
I checked out that moisture meter and I do believe there are better meters out there. In my opinion, Tramex makes excellent meters.

Try the Tramex model MEP. Realize that these meters are only surface moisture meters. If you want to get into a meter where you're physically putting probes into the wood, this isn't the meter for you.

http://www.professionalequipment.co...ve-moisture-meter-mep/lumber-moisture-meters/

Doug
 
aquadancer said:
One point of advice on surveying boats cored below waterline. Unless the boat has been hauled long enough for bottom paint to fully dry, moisure in the paint will peg the meter rendering it virually useless for evaluating bottom core condition.

Good surveyers will use the old-fashined rubber mallet and manually examine at all hardware and through hull locations.
Click to expand...

Somebody had to say it. Thank you...


Frank
 
Last edited:
fwebster said:
... Finally, if you don't want a cored hull boat don't look at Sea Rays over 34 feet, Hattaras, Bertrams, Tiara, Cabos, or a whole host of others. ...
Click to expand...

Are you saying Sea Rays under 34 feet do not have any hull coring? That is exactly what I would really like to hear...


Frank
 
No.

The under 34' boats for the most part have solid hulls, but most boats have some coring in the transoms, almost all have cores in the swim platforms, but the area of biggest concern for me would be the decks.

Everyone keeps banging the "hull cores are bad" drum so loudly that nearly everyone overlooks the fact that you are much more likely to have significant wet core problems with the deck than the hull. Boat builders know and understand the potential for damage with a hull core so the cored areas are designed to be fully encapsulated. Sometimes physical damage, poor maintenance, or a manufacturing defect does allow moisture to get to the hull core, but the decks have holes drilled or sawed in them everywhere to mount any number of stanchions, windlasses, lights, horns, windshields, hand rails, rod holders, hinges, etc. Every deck hole must be sealed with bedding compound and that compound must be checked and renewed periodically.

So coring is a fact of modern boat building and we must either figure out how to get comfortable with cored construction through proper surveys and due diligence followed by regular and proper maintenance or stick to canoes, canbotes and kayaks.
 
aquadancer said:
One point of advice on surveying boats cored below waterline. Unless the boat has been hauled long enough for bottom paint to fully dry, moisure in the paint will peg the meter rendering it virually useless for evaluating bottom core condition.

Good surveyers will use the old-fashined rubber mallet and manually examine at all hardware and through hull locations.
Click to expand...

No, a good surveyor and a person paying for the survey will insist on sanding parts of the bottom paint off, especially around anything mounted through the bottom of the boat, THEN moisture meter testing the areas.
You cant meter through bottom paint and most "surveyors" dont know what they are tapping anyhow
 
when i bought this boat, it was on land. when i arrived the morning of the survey, the surveryor was already there, on his back, tapping on the bottom of the boat with that little mallet for an hour. i was pretty ignorant regarding hull problems at that time (learned a lot since then from these boards and a problem a friend had with his boat) so i really didnt know what he was doing. i dont know if he had a moisture meter, but i do know he spent a lot of time under the boat.
 
My experience with the surveyors is similar but they will use the moisture meter as a quick check of potential problem spots prior to tapping with a mallet. There is no reason that a boat owner couldn't use a moisture meter over the storage season to check out their own boat or a future purchase. In fact one boat that I looked at with the surveyor, we were able to accurately outline the spread of hull side core wetness within inches using the GRP-33 prior to repair. So I think these meters have some value.

The surveyors that I have met seem to spend a lot of time with the mallet however because that is more reliable in their hands than the electronics. I know there are other (I.R.?) methods available for detecting hull moisture or voids.

As an aside, when I was looking at boats in storage last winter I ran the moisture meter over a 480DB near the chines. It pegged the meter right off the scale. I thought the boat had a wet hull, but the surveyor said that certain paints (I think this was a very black Trinidad anti-fouling) will fool the meter. So your point is valid about metering through bottom paint because you lose accuracy.
 
I am not implying that moisture meters have no value. However, a typical survey involves short hauling the boat just for the survey in which case moisture meter is useless below water line. If you're looking to buy a fully cored boat, ask for it to be hauled few days prior to scheduled survey so that bottom paint can dry out.

To Frank's point, most coring issues I've seen were not below water line but either on deck around hatches (lack of maintenance / flex from running with open hatches) and on the hullsides around engine room vents. Moisture meter can reliably identify and outline these areas.
 
there are alot of things in this world that go on without being discussed on the internet, if you are looking at a cored boat it is not taboo, but dont for a second feel comfortable that because you read on the internet that a cored bottom is usually fine- get a GOOD survey from someone who is accredited, pay the extra if its cored bottom to have parts of the bottom paint sanded off.
 
Gee, when I look for moisture in composites, I order and X-ray... and delams, ultrasonic inspection. Pity the boating industry hasn't borrowed from the aircraft industry...
 
You must log in or register to reply here.

Forum statistics

Threads
113,256
Messages
1,429,410
Members
61,135
Latest member
Gregger
Back
Top