Go Back  Offshoreonly.com > Technical > Fiberglass and Paint
acceptable moisture meter % >

acceptable moisture meter %

Notices

acceptable moisture meter %

Thread Tools
 
Old 10-20-2012, 01:40 PM
  #1  
Registered
Thread Starter
iTrader: (5)
 
Join Date: Aug 2010
Location: MA
Posts: 2,535
Likes: 0
Received 0 Likes on 0 Posts
Question acceptable moisture meter %

Going to look at a boat next Fri with / for a friend.
While I'm pretty versed at checking for transom & stringer rot in traditional ways. I figured this would give me a excuse to grab a moisture meter that I've been wanting anyway.
What's an acceptable #% ?

The meter I got is just a cheapo from Lowe's but seems to work well to me. I also got a couple lead wires like a multi meter has to probe in tight spots. The meter did not come with these though. Do I need to keep the pins the same distance apart when probing as they are affixed on the meter? Will being further apart or closer effect #% ?

Thanks, MD
scarab63 is offline  
Old 10-20-2012, 02:35 PM
  #2  
Registered
Thread Starter
iTrader: (5)
 
Join Date: Aug 2010
Location: MA
Posts: 2,535
Likes: 0
Received 0 Likes on 0 Posts
Default

Probed my pantera. The exh is removed so I poked @ pipe holes. Got 8% & 11% I know this wood is solid, so I guess that'll give me some type of test control baseline.
scarab63 is offline  
Old 10-20-2012, 05:08 PM
  #3  
Registered
 
Join Date: Sep 2011
Location: Rhode Island
Posts: 42
Likes: 0
Received 1 Like on 1 Post
Default

I have been using the JR Overseas GRP-33 moisture meter for years in my marine repair business and have found that when it starts pushing over 15% then I start probing harder & will do a sounding on the area...I have used a few different meters over the years and they are all a bit different in readings..The biggest thing is to check the calibration before using it & also know the substrate you are using it on bcs some paints will hold moisture and affect the reading..

-Written by another oldsalt,but a basic explanation,,

"Most of these meters are not actual "moisture meters" but they measure the capacitance (measured in farads) of the substrate with the theory being that a higher moisture content will have higher capacitance. As they measure capacitance rather than moisture many things will affect their readings such as connectors or metal tanks in contact with the area being measured, certain gel coats containing titanium dioxide, copper oxide, carbon and several other compounds with high capacitance (the same reason some bottom paints cause high readings"...

Best thing to do is what you did already and find areas you know are dry and get a reading and then find areas you know are wet to better understand how your type of meter works...The biggest problem I have seen over the years is the bedding compound not being replaced underneath the mechanical hardware(screws,bolts,cleats,ports,drive housings,tabs,hatches & the list goes on),,,It usually breaks down after 5 years & should be replaced,,,Most production companies are using Silicon or a marine grade silicon & IMHO doesn't last half as long as a good polyurethane,,,Stay away from 5200 & 4200 unless you never plan on taking the piece back off again,,,3m use to make a product call 101 but have discontinued it in favor of 3m 4000uv..If you really want to save your investment then decore those areas and fill the holes with either a poly or vinyl ester or epoxy filler & that will keep any new moisture from migrating further thru the core...
1OLDSALT2B is offline  
Old 10-21-2012, 01:31 AM
  #4  
Charter Member # 55
Charter Member
 
Griff's Avatar
 
Join Date: Oct 2000
Location: Omaha/LOTO
Posts: 19,555
Received 1,815 Likes on 903 Posts
Default

I highly doubt your cheapo Lowes meter will give any accurate readings. Those are made for construction applications and will not give accurate reading through fiberglass.
Griff is offline  
Old 10-21-2012, 05:52 AM
  #5  
Registered
iTrader: (2)
 
Craney's Avatar
 
Join Date: Oct 2004
Location: Clayton NJ
Posts: 2,449
Received 406 Likes on 181 Posts
Default

Originally Posted by Griff
I highly doubt your cheapo Lowes meter will give any accurate readings. Those are made for construction applications and will not give accurate reading through fiberglass.
Griff where can I get a meter that will work through fiberglass?
Craney is offline  
Old 10-21-2012, 08:30 AM
  #6  
Registered
Thread Starter
iTrader: (5)
 
Join Date: Aug 2010
Location: MA
Posts: 2,535
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by Griff
I highly doubt your cheapo Lowes meter will give any accurate readings. Those are made for construction applications and will not give accurate reading through fiberglass.
No it will not work thru fg.

That's why I got the leads so I could remove screws or fasteners from the strings, transom, etc....& probe the wood. Think this will work still? It seemed to work on my pipe cut outs.....I poked thru the resin & it gave me a reading
Should I just return this thing? & throw the cash towards a marine specific meter? This was just bought because it was ez & cheap. On the other hand I don't want to look like a douche bag showing up with this toy for the wrong app. Should I just stick with my old methods of poking & tapping until I get a marine specific meter?

MD

Last edited by scarab63; 10-21-2012 at 08:34 AM.
scarab63 is offline  
Old 10-21-2012, 09:13 AM
  #7  
Platinum Member
Platinum Member
 
jeff32's Avatar
 
Join Date: Jun 2004
Location: St-Hyacinthe, quebec, canada
Posts: 7,717
Received 366 Likes on 245 Posts
Default

mine was 800$. reads thru FG, but still need some human understanding of moisture like metal bracket and stuff like that... we even once had a reading very high from a surveyor said stringer was rotten, he drilled in it and the wood was dry, in like new condition... So, it's not always 100% truth, but sure gives a good general condition...
jeff32 is offline  
Old 10-21-2012, 09:37 AM
  #8  
Registered
 
Join Date: Nov 2009
Location: Montreal, Canada
Posts: 356
Received 9 Likes on 7 Posts
Default

Should I just stick with my old methods of poking & tapping until I get a marine specific meter?

MD[/QUOTE]

Great Idea

Sunday morning and raining here.....

Think I'll go poke and tap the the old lady with my moisture meter
Excess is offline  
Old 10-21-2012, 12:31 PM
  #9  
Charter Member # 55
Charter Member
 
Griff's Avatar
 
Join Date: Oct 2000
Location: Omaha/LOTO
Posts: 19,555
Received 1,815 Likes on 903 Posts
Default

Originally Posted by Craney
Griff where can I get a meter that will work through fiberglass?
Google marine moisture meter. They start around $400. Once in a while there is one on ebay.

Originally Posted by scarab63
No it will not work thru fg.

That's why I got the leads so I could remove screws or fasteners from the strings, transom, etc....& probe the wood. Think this will work still? It seemed to work on my pipe cut outs.....I poked thru the resin & it gave me a reading
Should I just return this thing? & throw the cash towards a marine specific meter? This was just bought because it was ez & cheap. On the other hand I don't want to look like a douche bag showing up with this toy for the wrong app. Should I just stick with my old methods of poking & tapping until I get a marine specific meter?

MD
The way you are using it should work ok.
Griff is offline  
Old 10-21-2012, 09:34 PM
  #10  
Registered
 
Join Date: Sep 2011
Location: Rhode Island
Posts: 42
Likes: 0
Received 1 Like on 1 Post
Default

Jamestown distributors in Bristol RI carry the JR Overseas GRP-33 for $349.99 & you can get it a bit cheaper if you open up an account with them,,,It's a good mid range meter but you still need to understand the substrates you're looking at and learn how to do a Sounding or a Tap out (tapping with hard rubber hammer or back of screw driver)

http://www.jamestowndistributors.com...Moisture+Meter
1OLDSALT2B is offline  


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.