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Facts About Boats

Little known and interesting Norfolk Broads nautical and marine forum topics.
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Miles
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Facts About Boats

Post by Miles »

G.R.P Boats Are Not Waterproof.

That's right...a fibreglass boat is not actually waterproof at all.
GRP boats are made up of a semi-permeable membrane. It is actually hygroscopic.
It is this process that actually leads to osmosis.
The best way to explain how osmosis occurs is to compare it to salt and water. If a cup of salt is poured on to a table forming a small pile. Next a cup of water is also poured on to the table right next to the salt. Once the salt comes into contact with the water, the salt will absorb the water. That is hygroscopic.
In this analogy, the pile of salt would be the GRP hull and the water would be the ocean, lake, river etc that a boat is emersed in.
The hygroscopic action is so strong that it will form blisters in the hull.
In fact, everything physical is in effect porous to some degree and most items contain more space than matter.
With GRP boats it is the hygroscopic action plus the existence of voids and air pockets within the fibreglass lamination process.
It has been said that osmosis begins when a new boat leaves it's factory.


Short Term Discomfort, Long Term Gain...
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