Portlight gasket leaks

[dehler25]

I had a very small dripping leak from two Lewmar portlights, I removed the offending units and rebedded them. Alas it started raining and two very small but pesky drips remained. The gaskets appear to be in remarkably good shape in that they are nicely soft, no evidence of compression and no cracking. The drips are so small that it is not apparent exactly where the water gets through as it appears as a wet spot in the channel and forms a droplet. Has anyone surfaced the gaskets to help seal with anything that does not simply cause a new problem? I have thought of using silicone spray, a light coat of Vaseline or waterproof grease just to improve on the seal, but would ask others experience before applying something that may be ugly to remove.

 

[jssailem]

Pictures of the issue help on this sight.
Lets look at the less obvious.
Do you have a fitting on the deck above the portlight and in the same area?
Some times when we see a leak we think portlights. Some times it is a screw from a nearby fitting, leaking water into the boat on top of a surface between the bottom of the deck and the inner ceiling, then running down and exiting near the portlight. How do I know? I just removed all the screws for the companionway slide, repotted & resealed them. No more water drips.

 

[Dave Groshong]

Lewmar recommends digging out the old sealant from where the extrusions butt on the outside, 2 butts if Old Standard and 1 if New Standard ports, and refilling them with new sealant.

 

[JamesG161]

If your Lewmar's are like the top picture on Dave's post, I solved mine easily. i.e. Two horizontal exterior seams.
I took some polyurethane clear sealant and filled those gaps, from the exterior.
I used this...
https://www.amazon.com/Sashco-13013...=2025&creative=165953&creativeASIN=B0012DIUYW

Jim...

PS: 2 years and no leaks.

 

[dehler25]

I only have the one seam and thought (my mistake!) that the seam was covered by the sealant just inside the perimeter. It was a Florida gully washer when I was leaving and I looked directly at the extrusion gap considering it as a source, a close lightning strike interrupted my introspection! I will address the gaps on my return and devout more attention to the others that I intend to pluck out as the ones I pulled came out ever so easily and they are all the same original bedding.

 

[dehler25]

Nothing above them other than the curved glass cabin top, but I know of exactly what you speak, I know of a leak on a boat that cofounded the owner for literally years eventually locating it about eight feet away from where the leak presented.

 

[quadrille38]

I had a very small dripping leak from two Lewmar portlights, I removed the offending units and rebedded them. Alas it started raining and two very small but pesky drips remained. The gaskets appear to be in remarkably good shape in that they are nicely soft, no evidence of compression and no cracking. The drips are so small that it is not apparent exactly where the water gets through as it appears as a wet spot in the channel and forms a droplet. Has anyone surfaced the gaskets to help seal with anything that does not simply cause a new problem? I have thought of using silicone spray, a light coat of Vaseline or waterproof grease just to improve on the seal, but would ask others experience before applying something that may be ugly to remove.

You may have already done this but I’ve found these ports are very sensitive to the least little amount of dust or dirt on the gasket causing it not so seal completely. So a wet cloth to wipe away any dirt from the gasket and the glass will help it get a better seal.

 

[rgranger]

Have you thought to try the pressure and soap trick?

I recently did this to my hobie 16. I kept getting water in the starboard hull. I held the nozzle of my shop vac (on reverse) and pressured the hull through the drain plug. A bucket of soapy water immediately showed the leak at one of the amma posts. It was VERY obvious. Had the hobie out Tuesday.... dry as a BONE!

@Crazy Dave Condon posted about doing this on a Hunter 26 by taping plastic over the companionway and running a leaf blower then sloshing down the deck with soapy water. At worse... your deck gets a nice cleaning.

 

[Crazy Dave Condon]

brush on soapy water vs. throwing a bucket out there. See air bubbling and there are your leakes.