Join Date: Jul 2008
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Re: (dam) Damp deck
, now that you've used the Ryobi moisture meter for a number of years, is there any chance you'd be willing to update your excellent Mythology blog with a chart giving % ranges for the Ryobi meter (hardwood setting, or whatever setting you and Sharon prefer)? Something similar to what you did with the Electrophysics meter would be great! (Perhaps just add a column for the analogous Ryobi readings.) I know I can't use the EP percentages directly because each of these meters is calibrated differently and the numbers are only relative.
|WHAT THESE NUMBERS MEAN ON CORED STRUCTURE (Again ..... only with the Electrophysics|
|10 - 13|
|Low = Core is dry to the touch.|
|14 - 16|
|Slightly elevated = Faint moisture can be drawn by applying|
light pressure to the core through a paper
|17 - 23|
|Elevated = Slight amount of moisture is visible in|
core when squeezed by hand pressure.
|24 - 39|
|High = Droplets can be squeezed from core with|
light finger pressure.
|Near saturation = Moisture is clearly visible in the core|
without pressure applied.
|Note : These interpretations above are valid for|
my meter only. We don't really care about
the numbers on uncored structure. The saturation
point for polyester resin is less than 2%
and the bottoms of most polyester boats will
get there at some point in their lives, sometimes
within a few short years. Saturation in solid
glass is not always a problem but if it is,
it will be visually noticeable in the form
of certain types of blisters (No meter required)
or easily found with my little brass hammer.
In rare cases, moisture in the laminate can
be a serious issue and you can read more
about that in Osmosis Mythology.
These are our guide numbers for the Ryobi on the hardwood setting.
Be advised that moisture meter readings and percussive soundings on frozen structure are not reliable. Meter readings on composite structures are relative and moisture percentages cannot be determined by these meters. Moisture levels where measured are taken with a capacitance type digital meter. Relative meter readings related to balsa cored structure are interpreted as follows ….
Meter reads 7 - 12 = Low : Core is dry to the touch.
Meter reads 13 -15 = Slightly elevated : Faint dampness can be felt in core.
Meter reads 16 - 18 =
Elevated : Slight moisture visible in core when squeezed by hand.
Meter reads 19 - 20
High : Droplets can be squeezed from core with light finger pressure and decay
is likely present.
Meter reads 21 + = Near saturation Moisture is clearly visible in core and decay is almost certain.
The hysterical laughter you hear as you drive a way in your"new" boat ..... is the seller.