Frozen (cold) Raw water Seacock and fiberglass cracks

[PDReynolds]

Hi Folks, My boat is on the hard in Canada and has been for 3 months. During my usual routine inspection, I noticed some strange cracks in the fiberglass around the raw water seacock. The boat is a Beneteau 423. It seems I forgot to open the seacock after the boat was on the hard to drain the fresh (river) water from the line.

I usually close this seacock while the boat is in the water and run a few gallons of antifreeze and then open it again once I pull the boat.

I plan to replace the seacock and scupper, but the fiberglass looks a little suspicious. Do I have anything to worry about here? The area of the hull is quite well re-inforced. The seacock is about 4 inches from the skeg and stern tube.

 

[thinwater]

The valve is NOT in the hull. Normally, the valve would burst if closed and leave the hull undamaged.

I suspect there is water intrusion between the through hull and the hull and that THAT is what expanded. I would think that hull was solid glass, but perhaps there is a void. It also looks like the gelcoat is quite thick; perhaps that is all that cracked.

 

[Captain Larry-DH]

The valve is NOT in the hull. Normally, the valve would burst if closed and leave the hull undamaged.

I suspect there is water intrusion between the through hull and the hull and that THAT is what expanded. I would think that hull was solid glass, but perhaps there is a void. It also looks like the gelcoat is quite thick; perhaps that is all that cracked.

I agree with @thinwater but I would also be concerned about water intrusion into the underlying laminate. I’d grind back the gelcoat cracks and dry it out thoroughly, then recoat with gelcoat or epoxy.

 

[Barnacle Bill]

Ya, that doesn't look like a laminate crack, but perhaps gelcoat or faring compound. When you have the seacock out, it will be easy to grind out the area, clean it up and fiberglass it up with cloth and resin. Also the hull could be cored there. If so, then I would recommend removing all core around the sea cock and making the perimeter solid fiberglass before installing the new fitting. That way you shouldn't have future concerns about any water intrusion. Of course, if it is cored and wet, you really need to remove ALL wet core before fiberglassing in which case that could extend who knows how many inches/feet from the seacock area.

 

[Captain Larry-DH]

Also the hull could be cored there.

Helpful, but I doubt the maker would have put the thru-hull where there's coring.