Window frame leak

[osprey877]

Attached are three photos showing one of the windows (portlights) on the cabin trunk of my boat. There is a small leak in the upper left corner of the window. It looks to me like there was some sort of a blow to the cabin trunk side that pushed it back from the aluminum frame, breaking the seal between the frame and the side of cabin top. The leak is quite small and local and the tape shown in one of the photos stops the leak. However I would like a more permanent solution.
I know the correct way to fix it is to remove the frame, dry out the core, fix the corner and rebed the frame. However, that is not possible. The frame has been in the boat for 30 odd years and is permanently attached. It cannot be removed without doing irreparable damage to it, which would mean replacing all 6 windows on the boat as I doubt the frame extrusion is still available. So what I need is a sealant that I can force between the frame and the cabin top to repair the broken seal. I am thinking I would set up a vacu-bag on the inside of the window frame to suck out the moisture and maybe draw the new sealant into the gap, like a resin infusion system. The sealants I’m considering are epoxy resin, thickened epoxy resin, LifeSeal bedding compound, butyl glazing putty, 3m 4200, or some sort of silicone sealant. Any suggestions/ advice welcome. I will only get one kick at the can as I won’t be able to remove what I put in, so I’m being a bit cautious. Thanks.

[bil56]

peel off that shard of gelcoat first to check what's underneath (a mini grinder would be nice)
if you have a vacuum pump, your idea of applying a soft silicone or PU gasket is good, no epoxy too stiff

[Tetepare]

Originally Posted by bil56

peel off that shard of gelcoat first to check what's underneath (a mini grinder would be nice)
if you have a vacuum pump, your idea of applying a soft silicone or PU gasket is good, no epoxy too stiff

Good, simple advice.

[osprey877]

Originally Posted by bil56

peel off that shard of gelcoat first to check what's underneath (a mini grinder would be nice)
if you have a vacuum pump, your idea of applying a soft silicone or PU gasket is good, no epoxy too stiff

Thanks for the reply. Since writing my original post I came across a product called “Captain Tolleys creeping crack cure” which is a very thin sealant that claims to rely on capillary action to fill small gaps. Will try it first before something thicker if it doesn’t work.

[Oeanda]

Let us know how it works. I’ve got some onboard, left here by the PO, and have been contemplating using it for the same issue.

[osprey877]

Originally Posted by Oeanda

Let us know how it works. I’ve got some onboard, left here by the PO, and have been contemplating using it for the same issue.

Pleased to report that Captain Tulley’s creeping crack sealant worked as advertised. Very simple to apply with minimal prep. Just clean and dry the area then apply a thin line of the adhesive to the crack or suspected leaking seam. Wait half an hour for it to get sucked into the crack and set up, then repeat until crack/seam stops absorbing any more liquid. Hopefully it is a permanent repair, but only time will tell.