How to Fix Leaking Portlights DIY Style

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After discovering leaks in the portlights during a voyage to Trinidad, Adam Land embarks on a journey of repair that leads him through the pitfalls of corrosion, the intricacies of part replacements, and the satisfaction of self-accomplished repairs. This tale is not just about leaks; its a DIY portlight fix that proves that there's only two ways to do a project: right, or again!

Sometimes It’s Just Better to Do It Yourself: Leaking Portlights
By Adam Land aboard SV Solmate 

We found a leak in one of Solmate’s portlights as we were heading for Trinidad in the Spring of 2023. When we got the boat hauled, we inspected the leaky portlight with a contractor. We determined that the leak was most likely caused by corrosion in the portlight. As far as we could tell, the corrosion likely originated where stainless steel bolts contact the aluminum frames to hold them together. I assumed that during the factory installation of the portlights no anticorrosive was used to isolate the two metals. We then inspected the other hatches and portlights, and found others had leaked as well, and there was growing corrosion on all of them. The contractor suggested that he remove all the hatches and portlights, strip the paint, remove the corrosion, and refinish them, and we engaged him to do that rather expensive job.

When we came to splash in the Fall, the portlights looked great. 

Unfortunately, we learned during the 2023-4 season that the refinish process weakened some of the threads that hold the latch receivers and thus, on each of three separate portlights, one of its latch receivers failed. The failed latch receiver did not cause any obvious leaking, but we felt generally unsafe about having less than all the latches working. After calls to Lewmar, we learned that Lewmar would sell us just the outside frame for the portlight, and because the outer frame contains the latch receivers, installing new outer frames would resolve the issue. It took a bit of work just to get the outer frames ordered as Lewmar doesn’t have a part number for the outer frame. After a few days and a bunch of calls, Lewmar was able to make a part number for the outer frame, and a part number allows a reseller to order the part. For a reseller, we used Sailorman in Fort Lauderdale. Sailorman is a great resource for odds and ends like this.

Never having messed with portlights before we were not really sure what we were getting into. Undaunted by lack of knowledge but knowing that the guy in Trinidad could do it, we began. From inside the boat, we removed the dozen or so frame bolts that hold the inner frame to the outer frame. Once we found our 3mm Torx heads, the bolts came out fairly easily. I think they came out easily because I had the Trini contractor liberally use Tef-gel when he reassembled the refinished portlights. If you aren’t familiar with Tef-gel, it’s a paste that contains 40% PTFE; Tef-gel essentially eliminates galvanic corrosion between dissimilar metals. 

Once the interior frames were carefully placed so they didn’t get scratched, we unlocked and removed the opening window portion. To remove the window, we removed the 4mm Torx bolts along the hinge, being careful to catch the nut at the bottom before removing the screw. With all 4 hinge bolts removed we carefully removed and set the window down. As we removed the first one, several small parts fell down on the counter and we thus discovered that each of the four hinges had a small, but necessary part. It was fortunate that the portlight hatches tilted inward so the small parts fell inside the boat.

We collected the small parts from the first portlight window and were much more careful with the other window removals, making  sure to rescue the small parts as the bolts came out. 

Now on to the outer frame. With the inner frame and the windows removed, we fully expected the outer frame to essentially lift out. But it didn’t. Why not? It was caulked in rather well. We worked a razor between the outer frame and the acrylic window in which the outer frame sat. It was slow going, but after about 20 minutes, I had sufficiently circumscribed the outer frame when it first began to move. Since we were replacing the frame, we didn’t worry about damage, so we razored and pushed and razored and pushed, occasionally pushing hard enough to bend the outer frame, but it eventually came out. We were somewhat surprised to see the thickness of the acrylic windows in which the portlights were set, about 15 mm. We put 2” blue tape around the exterior adjacent to where the outer frame would sit. We then applied a black Sikaflex caulk around the contacting areas of the new outer frame. Specifically, we used Sikaflex 295 UV, which is a one-component polyurethane adhesive that cures when exposed to atmospheric moisture. Once all the contacting surfaces were caulked, we inserted the new outer frame in its place.

With the frame in place, we positioned the old inner frame and began to screw in the 3mm Torx bolts. I set my screw gun to the lightest clutch position so that the frame would not screw in tightly and screwed in each of the bolts after liberally applying Tef-gel to it. Once the frame bolts were in place, we reattached the portlight windows by placing the bolt / hinge pins through the positioned hinge. To assist with keeping the small additional parts in place as we installed the hinge pins, we used a bit of Tef-gel as a temporary “gooey” adhesive. Once pinned, we held the lower nut in position and turned the bolt until it tightened. After several minutes, we removed the blue tape--in time that the caulk was sufficiently set that it would not run, but not so set that it would prevent easy removal of the tape. Then, with the portlights mostly installed and the tape removed, we latched the portlight hatch closed. Happily, all the latches now worked again. 

After allowing the caulk to set for 24 hours, I got my 3mm Torx screwdriver and tightened each of the loosely attached frame bolts by hand, and the installation was complete. I felt much more confident with the new frames and latch receivers. In the future I plan to remove a few of the 3mm frame bolts each month and reapply Tef-gel in an effort to mitigate any new corrosion.

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