Weeping Hull

[Neil]

My boat has a tiny area of GRP (about the size of a 5 penny piece) on the inside of the cockpit (on the single skin floor), which weeps. Now having read many a posting about osmosis, I've come to the conclusion, that's what it must be. I can not see ANY other signs though, no external blisters to be seen for example. Could it be that I just have this one tiny area to contend with ? and what's the best treatment (given the tiny extent of the problem) ? I've tried just re-painting with the non-slip paint that already covers the inner hull, but it still weeps.

Thanks in advance.

Neil.

 

[tony_brighton]

You sure its not just a dry spot in the laminate? How old is the boat?

 

[vyv_cox]

I don't see how this can be osmosis, which by definition requires two different concentrations of a fluid to be on opposing sides of a membrane. If water is coming right through it must have washed/diluted the higher concentration and there is no membrane, so no driving force.

It sounds much more like either a crack or possibly a layup defect. Inspect the outside very carefully, if necessary using a small grinder or hand tool to remove some surface material. This should help to find the crack. If this doesn't work, try filling the suspect area of the boat with water plus some colouring agent and inspect from outside.

Once found you can decide what treatment is necessary. A small weep can be fixed with gel coat but more may need a layer or two of glass. I have found the two-pack epoxy repair pastes to be very effective for this kind of job, they can be diluted with water to assist with penetrating cracks and polished, before setting, to a good finish. Leaks are almost impossible to fix from inside, much easier from outside.

 

[Guest]

I have a Bruce Roberts 30 with weeping hull. It can only be fixed from the outside, however, it is a straight forward exercise. Dry out the boat, rub down the porous areas from the outside, using an electric sand disc, stick a small patch of fibregalss with grp.Paint with a thick primer paint (Blake underwater primer). Good luck