Fixing leaking fixed portlights

Stu Jackson · October 28, 2014, 12:27:00 PM

I added a link back to this in the Tech wiki under Port Lights & Hatches, and also to the "101 Topics" Leaky Portlights 101.

rmbrown · July 21, 2017, 12:06:49 PM

https://youtu.be/MQyjxVUskd8

Anyone tried this approach for fixed port rebedding using 3M VHB tape and the Dow 795? I love the idea of the tape taking the mechanical load, but would love to hear about any experience you guys might have had for good or for bad.

Jeff Tancock · July 24, 2017, 08:29:41 AM

Looks interesting.
I need to do this project but procrastinating...........

rmbrown · August 13, 2017, 03:04:19 PM

I love the tape, but the approach didn't work for me... There isn't enough clearance between the edge of the lens and the fiberglass to get a good bead of 795. I removed the lens... TWICE... from the VHB, which is quite tenacious!

I'd use this approach if I was cutting new lenses, which I'd make without the beveled edge.

For now, back to plan A. :)

DaveBMusik · August 13, 2017, 07:21:17 PM

Quote from: rmbrown on August 13, 2017, 03:04:19 PM
I love the tape, but the approach didn't work for me... There isn't enough clearance between the edge of the lens and the fiberglass to get a good bead of 795. I removed the lens... TWICE... from the VHB, which is quite tenacious!

I'd use this approach if I was cutting new lenses, which I'd make without the beveled edge.

For now, back to plan A. :)

Which tape did you use? 5952, 5962 or something else?

rmbrown · August 14, 2017, 06:07:13 AM

I bought 5292, although I might get thicker next time. Casey recommends 4991. (https://www.sailmagazine.com/diy/replacing-fixed-portlights)

To be clear, the issue wasn't with the tape. That stuff is the bomb, in my opinion. The issue is how tightly that lens (at least mine) fits into that opening. There's no groove or gap around the lens, or not enough of one to matter, even with 2mm of tape ( I double mine up as an experiment) the beveled edge of the lens touches the fiberglass.

The technique would work fine if I cut the bevel off the lens but no need for that. I'll figure out a way to hold those lenses in place and just use the 795.

Noah · August 14, 2017, 06:47:36 AM

If you don't put screws to hold it (at least temporarily) you could use a clamping fixture like Fred did.
http://c34.org/bbs/index.php/topic,7688.msg52834.html#msg52834

rmbrown · August 14, 2017, 07:35:56 AM

Thanks Noah (and Fred!)... That's the path I'm on. :)

rmbrown · August 21, 2017, 02:17:35 PM

I tried the wooden jig on the starboard forward fixed port. I blame my execution rather than the idea, but let's just say it wasn't my best performance. In the end, I believe it's resealed and, if you don't look too close, cosmetically adequate.

Both a dock neighbor and my local go-to boat maintenance guy suggested suctions cups so I tried that for the port window. It went fabulous!

rmbrown · August 21, 2017, 02:19:45 PM

I apologize for the non-rotated images. They show up on my phone and computer correctly. Anyone know what I did wrong, speak up!

Noah · August 21, 2017, 02:32:31 PM

Suction cup are an interesting approach. My current ports have screws and I believe I will go with screws again when I do them this later year.

rmbrown · August 21, 2017, 02:34:11 PM

If I'd had screws, I'd definitely have kept them!

rmbrown · August 21, 2017, 02:35:49 PM

If anyone goes for suction cups... The following is a link to show you what I used. Mine were $4.97 at wal-mart, however.

https://www.amazon.com/Peerless-3006C161PK-Mount-Suction-Chrome/dp/B005SQBZKK/ref=sr_1_fkmr0_1?ie=UTF8&qid=1503351301&sr=8-1-fkmr0&keywords=peerless+shower+suction

Whiskymac · January 06, 2020, 01:31:56 PM

Sorry to resurrect an old post here but I am planning to to reinstall my aft windows/port lights
I read that a combo of the 3H VHB/Dow 795 is not recommended by those who have tried but I was wondering whether a 3H VHB/Butyl tape combo might work any better.? I was thinking the tape would provide the adhesion qualities needed and then if I ran a generous bead of butyl next to it it would provide the water proofing/gap filling qualities?

rmbrown · January 06, 2020, 01:47:57 PM

I think that butyl tape is the right material for almost everything... but not here. problem is, with my windows anyway, that there's no mechanical fastener... If there were screws I'd use butyl tape and nothing else.

The VHB is a fantastic idea, and would no doubt work if you either had windows with 90 degree edges going into an oversized recess or if you had a tapered edge (like mine) and a lens that had more room around it. My problem was that, once the old sealant was out, if you tried to put the lens in the hole, it was too big, IF you tried to get it near the bottom. It was sized to have a pretty hefty bead of 795 underneath it and the stuff I had was maybe 1/8" thick... I even tried doubling it up, but it was too big, relative to the recess, to make good contact with the tape all around. Thicker tape might well have worked.

While the tape may be strong enough to hold plate glass in a metal frame on a skyscraper, I have my doubts about it holding plexi to my fiberglass hull, and even more doubts about my ability to make it waterproof, so I just considered the tape as a "clamp" while the 795 cured. When the tape failed, I got creative and held the lens in place a different way.