Regarding percentage of moisture: Baltek Corp (sellers of balsa and other core materials) detailed the performance issues of "wet" core in their "Proper Core Installation" (2009) document.
In short, balsa starts out with around 10 to 12% moisture content. The "Fiber Saturation Point" where the structure of the wood cannot retain any more water vapor is around 28%. Baltek goes on to state that moisture levels 20% or below is not enough to condemn (or even justify stripping the skin and replacing the core) a boat owing to a reduction on shear or compression strength. After spending the last winter repairing balsa core that had completely failed (rotted, black, stinky, delaminated from the skin) and in the process testing the bond strength if damp balsa (tan/brown colored, not stinky, "had to pry the glass skin off") to the 43 year old fiberglass (polyester resin) I agree with Baltek's claim. The combo of a moisture meter and a light tapping around suspect areas should be used. On Calypso the totally failed areas sounded so different than the still well bonded areas that I could easily find them, even with ear plugs in. If one is not interested or capable in performing repairs in the usual C&C wet core areas, by all means use the highest standards regarding wet deck core. If you are willing to DIY small repairs jobs it is messy but not difficult. Having a boat yard perform the repairs, especially if major, likely exceeds the value of the boat unless it hold special value to a determined owner. This winter's projects on Calypso's deck cost the co-owner and I around $2,500 in materials and the boat cover. The cost in hours was fortunately not well documented but I estimate it around a combined 25 to 30 hours a week for 12 weeks. If we had our local boat yard perform the work I estimate it would have been $40,000 in materials, labor, and yard fees. Martin Calypso 1970 C&C 43 Seattle From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of Pierre Tremblay Sent: Tuesday, April 09, 2013 10:35 AM To: cnc-list@cnc-list.com Subject: Re: Stus-List C&C 30 - Pinless Moisture Detector Just back from Canadian Tire with a Mastercraft pinless moisture meter. In soft wood mode, top of my desk (presswood modular furniture type) say 15%, and it can see my hand (jump to 18%) under the desk top (1 inch thick). On my hand, it goes off the scale exactly as the CT33 of my surveyor was doing. Pierre Tremblay Avalanche, #54988 C&C38-3 WK On 2013-04-09, at 9:47, Stevan Plavsa <stevanpla...@gmail.com<mailto:stevanpla...@gmail.com>> wrote: I never had any trouble using mine, what people deem so difficult about using them I'm not sure. The mastercraft one is a quarter of the cost, go ahead and try it and report back. I'de be curious to see how it measures up against the CT33. On Tue, Apr 9, 2013 at 8:45 AM, Hoyt, Mike <mike.h...@impgroup.com<mailto:mike.h...@impgroup.com>> wrote: Don I asked on the Canadian Tire website a similar question about that product a few months ago. They finally answered and say it is similar to CT33 because it ises a similar inductance method. At half price at $45 I think it is worth a try anyway. You should also be aware that these meters are not all that easy to use. I borrowed Graham's Electrophysics meter (CT100 I believe) and within 10 minutes realized I had no clue how to use it properly. Mike From: CnC-List [mailto:cnc-list-boun...@cnc-list.com<mailto:cnc-list-boun...@cnc-list.com>] On Behalf Of Don Harben Sent: Monday, April 08, 2013 9:31 PM To: cnc-list@cnc-list.com<mailto:cnc-list@cnc-list.com> Subject: Re: Stus-List C&C 30 - Pinless Moisture Detector Hi folks, This has been a very useful discussion for me but especially for my friend currently looking at boats. Does anybody have comments or experience on this Pinless Moisture Detector? http://www.canadiantire.ca/AST/browse/6/Tools/MeasuringTools/SpecialtyMeasuring/PRD~0574572P/Mastercraft+Pinless+Moisture+Detector.jsp?locale=en _______________________________________________ This List is provided by the C&C Photo Album http://www.cncphotoalbum.com/ CnC-List@cnc-list.com<mailto:CnC-List@cnc-list.com> _______________________________________________ This List is provided by the C&C Photo Album http://www.cncphotoalbum.com/ CnC-List@cnc-list.com<mailto:CnC-List@cnc-list.com>
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