Water Absorption

[Andy G]

I was just wondering how much water would you expect a boat(fibreglass) to absorb through the hull over the years.

I been told you can expect an old 36' boat to absorb up to 500 lbs of water in weight, can anyone confirm if this figure is accurate, or is that over the top?

 

[psneeld]

Fiberglass can definitely absorb a pretty good percentage of it's own weight in water. I couldn't lay my hands on it quickly but I thought it was somewhere between 5-10% of the weight of the immersed glass.

500 pounds sounds like a bit much for a 36 foot boat...but without guestimating the weight of the immersed glass...based on hull design and bottom thickness...really hard to guess.

 

[Flatsflyer]

If this is true, so much for moisture meters and sounding the hull.

 

[psneeld]

If this is true, so much for moisture meters and sounding the hull.

It's a black art for sure and despite many thinking they are experts with moisture meters....I have my reservations about their real effectiveness.

Way too many erroneous reports for my satisfaction.

Funny how accurate they are when the tests show dry or moisture and you can see through to the coring from the bottom/other side.