Port light reseal

[jjns]

This spring will be the task of pulling all the hatches and port lights and resealing them and potting and rebedding all the hardware on the cabin top with Butyl tape.

The port lights are Aitkins and Hoyle 5x12 opening lights, the cabin top is cored and I fully expect to find exposed core when I pull the lights.

So is it better to pot them out with epoxy to seal the core or leave it unsealed in case a leaks develop in the future and being open will make it easier to spot.

In talking around the yard I get the impression that most favour the latter.

However, it seems to me that if all the penetrations have been potted then there should be no worries about future water intrusion to the core and hence no need to leave a place where it can escape (or enter).

[mitiempo]

If when you remove the portlights/hatches you find exposed core as I'm sure you will it needs to be replaced with thickened epoxy. If you don't a future leak will not be visible as it would go directly into the core. The solution is to remove the core all around the cutout as well as around the fastener holes. Fill it with thickened epoxy and then redrill the fastener holes. This way you will see a leak inside the boat and can attend to it rather than it just rotting the core. With any luck there will not be any core damage already present. Here's a link to an excellent how-to for potting holes for fasteners.
Sealing Deck Penetrations to Prevent Core Rot Photo Gallery by Compass Marine at pbase.com

[sailingdog]

Generally, deck hardware and ports should only be sealed on the deck side... that way, if a leak develops, it can be seen on the inside, and warn you that you have a problem.

Properly potting the cutout and fastener holes is key.

[jjns]

So, if i read this correctly, once the cut-out/fastener area is potted, then the light goes back in with mastic on the outboard flange only?
If a leak develops I will see the trace on the inside and all that will likely be required is to pull and re-bed.

Gee, good thing I only have 9 to do.
Oh, and the handrails, and 2 hatches and the companion way cover and the genoa tracks, stanchions, maybe the pushpit, pullpit and about 40 or so other things.

Gonna be a very long summer.

[mitiempo]

That's correct, but fill the cut edge of the hole with thickened epoxy as well as the holes. It's not too long a job - unless you find wet core it should go pretty quickly.

[sailingdog]

Yup... Got it in one...

Originally Posted by jjns

So, if i read this correctly, once the cut-out/fastener area is potted, then the light goes back in with mastic on the outboard flange only?
If a leak develops I will see the trace on the inside and all that will likely be required is to pull and re-bed.

Gee, good thing I only have 9 to do.
Oh, and the handrails, and 2 hatches and the companion way cover and the genoa tracks, stanchions, maybe the pushpit, pullpit and about 40 or so other things.

Gonna be a very long summer.