Help - can’t identify cause root cause of leaks!

[Mad Harold]

I had a difficult leak in a similar place to yours.

eventually found it was leaking through the cabin side when sanding down some paint bubbles. On removing the bubbled paint I found a few rusted pinholes that had penetrated the metal. Body filler fixed it.

Worth checking?

[mark99]

Spent a few days sorting a leak recently. Only to find there were two leaks - the sucker punch. One where chimney seal was. The other in the side hatch seal which had a slight slit.

 

[system 4-50]

One thing has always mystified me.  How does the next leak know to start as soon as you have stopped the previous leak?  

Its similar to how does the last baked bean sticking in the pan know that it is the last one and has to stay there nomatter what.  There is a conspiracy amongst inanimate objects, I'm sure of it.

Edited December 18, 2018 by system 4-50

[The Welsh Cruiser]

+1 for creeping crap cure, it really does work.

[Bee]

I would cut away the foam insulation below the window, right back to bare steel, then you really would see what is happening. If it is the window then you've found it. If it isn't the window then you can repair the foam with one of those aerosol things from Screwfix, If your window has a curved bottom frame then just make sure that there are no uninsulated corners. Check the fixings for the window, self tappers? stainless? rusted out galvanised? Its not hard to tap threads in the cabin side and get those little dome headed stainless bolt thingys with allen key socket from Screwfix or even better ones from somewhere else, a much more positive fixing.

[Horace42]

3 hours ago, koukouvagia said:

Also bear in mind that water can travel long distances along gunwales etc., so the leaking window might be at the far end of the boat.

I go along with that. In my case rainwater got in through a window by collecting on the upper horizontal glazing bar of the ventilation window and running to one end and passing a poor fitting rubber seal (shrunk with age I guess) leaving a gap at the end inside the frame channel, to drip down between the glass and frame but being inside the framel, unseen, and then to drip out at the bottom to seep along the underside of the gunnel, still unseen, a few feet or so, to eventually appear when it 'rotted' through the top edge of the wood panel - and judging by the rust when the panel was repaired, could have been like it for years. 

I replaced all the rubber seals, but additionally embedded the ends in silicone sealant. That fixed it.  

 

[roland elsdon]

A layer of stern tube grease around the suspect joint will help diagnosis. Unlike other temporary compounds it will seal when wet.

part of our 5 month lay up is grease round all portholes glass and the rings, and over the vent flanges. Those joints move with expansion .