Bilge water

[boy boater]

Is water in the bilge of a grp boat a problem with regard to the structural integrity of the hull? I've seen particularly sports boats with removable plugs at the bottom of the transom for the draining of water. Is there a danger that water in the bilge can seep through the grp from inside the hull and cause osmosis, for example?

 

[hlb]

It should not do any harm, many boats have some water in the bilge all the time.

 

[boy boater]

I see lots of views but only one reply!
I realise that lots of grp boats have water in the bilges - but my question relates to whether or not it is doing any harm to the hull.
Are there any grp experts out there who can help wrt whether water in the bilge of a grp boat is likely to lead to hull problems.
Is grp porous?
I've always been led to believe that a scuff on the gelcoat below the waterline needs to be repaired quickly to avoid the ingress of water.
With no gelcoat to protect the inner surface of the hull cannot bilge water seep into the grp from this direction - and hence cause damage?

 

[Cliveshep]

You are worrying about nothing unless your boat is so badly laid up there are voids in the layup into which water can seep along the fibres and then perhaps freeze. That is pretty extreme and very very unlikely.

Like the man says, most boats have bilge water to some extent, mine has never less than around 5 gallons as it lies in the keel below the intake of the bilge pump - after more than 40 years of that it has done no discernible damage apart from moving an oil spillage from a clumsy engineer in it's past and spreading it everywhere.

Repairs to gel coat do prevent ingress of water along the fibres IF they were not properly "wetted" during hull lay up and for that reason it is recommended that they be repaired if possible. Again, I've got no end of scuffs along the waterline, and it's still happily afloat.

 

[boy boater]

Thank you, Cliveshep, for your most comprehensive and reassuring reply. It was greatly appreciated.