Leaky portholes HELP!

[Bigjim]

The angled one in the previous link is quite expensive.

[a64pilot]

Even though it’s a silicone the GE silpruf is a very good sealant.
I use it to seal my chain plates, it’s supposedly the best thing there is for that, lasts for decades apparently.
https://www.siliconeforbuilding.com/...0-SilPruf.aspx

[Bill O]

Originally Posted by a64pilot

Even though it’s a silicone the GE silpruf is a very good sealant.
I use it to seal my chain plates, it’s supposedly the best thing there is for that, lasts for decades apparently.
https://www.siliconeforbuilding.com/...0-SilPruf.aspx

Not certain about "decades", but we used 3M silicone on our Beckson ports. Good for nearly a decade so far with no leaks.

Have used structural silicone for our dodger glass and hatches. It works very well if one follows the recommended bead amount.

[Discovery 15797]

First...never use butyl tape...that stuff sucks. It is usually much firmer and not as pliable as pure butyl rubber.

Personally, I would never use sealants on a port or hatch frame. The metal heats and expands at different rates than does the FRP. (Same for plastic...but not nearly as drastic). That heating and cooling cause expansion and contraction which puts tension on the sealant eventually causing it to break the seal (either against the fiberglass or the portal flange) which leads to a leak. Simply put...this will not happen with properly bedded butyl rubber.

4 years ago I bought 8 ports from Newfound Metals to replace the plastic ones in the hull (I don't know why any boat builder would put plastic opening ports in a hull..but they did). I used butyl in all ports...I also re-bedded all my pilothouse windows and frames with butyl and have not worried since.

Real butyl is messy to work with (unlike butyl tape) but IMHO it is the best for sealing ports, hatches, windows, etc. Another down side is that It's also very susceptible to chemicals...including plastic cleaner. It will also 'ooze' for a while as it gets hotter and need to be 'cleaned up.'

I order my butyl from NFM...(https://newfoundmetals.com/product/butyl-bedding/) and always keep a couple extra rolls on the boat.

[Lepke]

If you can't find the correct angle...
Wood boat hulls with tumble home, I drill a 1/4" drain line as close to the seal as possible and use 1/4" plastic tubing, pushed thru the hole and cut to match the angles. On the top I drill out a bigger hole to make a sump and epoxy in the tubing. On the bottom I usually just seal wood with paint or colored epoxy for fiberglass. I have several ports on my current boat done this way. I've never had one plug up but would be easy to clean. Drain isn't obvious. You could do it with stainless tubing, but the plastic blends in.

[chowdan]

Originally Posted by Lepke

If you can't find the correct angle...
Wood boat hulls with tumble home, I drill a 1/4" drain line as close to the seal as possible and use 1/4" plastic tubing, pushed thru the hole and cut to match the angles. On the top I drill out a bigger hole to make a sump and epoxy in the tubing. On the bottom I usually just seal wood with paint or colored epoxy for fiberglass. I have several ports on my current boat done this way. I've never had one plug up but would be easy to clean. Drain isn't obvious. You could do it with stainless tubing, but the plastic blends in.

Do you have photos of your setup?

I've thought about this. The one issue I have with it is that sealing that tubing seems like a PITA due to epoxy not bonding to metal very well.

[CassidyNZ]

Originally Posted by Bigjim

Another thing I noticed is that some porthole models are designed for angled deck houses. But, I can't find anyplace where this feature is offered. Most go straight through so the water simply fills up the porthole and sits there until it evaporates.


Anyone know where you can get those angled windows?

The cross section you show indicates a much deeper port than I’m used to. I have Lewmar ports which have the glass seating well inside the frame and the rubber and rim very thin. Result of that is very little water gathers on the port. I can’t recall ever having to wipe the outside before opening.

Is your diagram a “representation” or does the glass actually close onto the inside of the frame as shown? If yes, that’s not very clever design.

[chowdan]

Originally Posted by CassidyNZ

The cross section you show indicates a much deeper port than I’m used to. I have Lewmar ports which have the glass seating well inside the frame and the rubber and rim very thin. Result of that is very little water gathers on the port. I can’t recall ever having to wipe the outside before opening.

Is your diagram a “representation” or does the glass actually close onto the inside of the frame as shown? If yes, that’s not very clever design.

For regular vertical cabin top, or slightly slanted, it works just fine. On a boat like mine, or on ones such as a swan, the design doesnt work the best.

The lewmar design you describe would probably be the better design for super angled cabin tops. The problem I have with them is that I feel like they are cheaply made and not as durable feeling as NFM.

My cabin thickness is roughly 1.5" thick if I recall correctly, so that was another reason i went with new found metals.

[Teknishn]

Don't know the age of your boat, but are you sure the leaks are coming from the outside of the boat and not from water intrusion into the coachtop sidewalls? When you pulled out the portlights was the sidewall coring material dry? Had this problem on my '81 Hunter 27. Outsides were sealing well but the portlights were still leaking on the inside from water intrusion from a topside hatch.

For sealants I'm using 3M 4200 for the portlights along with Gray RV Tape for the bezels (a form of butyl tape used to seal the roofs of RV's which stay pliable for a few years).

[CassidyNZ]

Originally Posted by chowdan

The lewmar design you describe would probably be the better design for super angled cabin tops. The problem I have with them is that I feel like they are cheaply made and not as durable feeling as NFM.

My cabin thickness is roughly 1.5" thick if I recall correctly, so that was another reason i went with new found metals.

Actually my coachroof has near-vertical sides. In an earlier post someone mentioned Lewmar ports made of plastic being not so flash. Mine are made of aluminium with 8mm acrylic panes and are pretty robust construction. Assuming they are original (no reason not to), they have been doing a pretty good job since 1986

I am presently in a program of replacement of the acrylic panes and seals as the originals have been distorted over time by the catches and have started leaking but the frames are still perfect.

I have no affiliation with Lewmar and don’t approve of their after sales support and marketing philosophy

[gulfstar37]

Originally Posted by Bigjim

I pulled off one of the frames and scraped off the butyl and replaced it with Life Caulk, which is polysulfide. It rained the next day and there were no leaks around the frame.

I'm going to pull the remaining frames, scrape off the butyl and replace it with the Life Caulk. Butyl is probably better when you have steel or bronze. Life Caulk is probably better with plastic. Had I known, I would have dropped some big money and got metal portholes.

Another thing I noticed is that some porthole models are designed for angled deck houses. But, I can't find anyplace where this feature is offered. Most go straight through so the water simply fills up the porthole and sits there until it evaporates.


Anyone know where you can get those angled windows?

Haven't seen angles ones like you show but Beckson makes ports for side angle install to minimize amount of residual water trapped in window. We installed the rain drain and works very well. Note there will be some drips directly following a downpour mostly from screen but after 15 minutes it's dry. See attached photo.

[siamese]

I replaced a Beckson port a couple years ago. I recall that Beckson was very specific about using silicone. Not what you'd expect for a marine product, but they warn that 3M 4000 or 4200 or similar will attach the plastic and degrade it.

This spring, I replaced the acrylic windows in the Lewmar ports on the side of my cabin (Catalina 28). My research showed that this is another instance where 3M 4000 & 4200 are not recommended, as they'll degrade the plastic. I used Dow 795 silicone adhesive.

[a64pilot]

Originally Posted by Bill O

Not certain about "decades", but we used 3M silicone on our Beckson ports. Good for nearly a decade so far with no leaks.

Have used structural silicone for our dodger glass and hatches. It works very well if one follows the recommended bead amount.

Click on the link and read the spec sheet, this is not your normal silicone.

[Bigjim]

Those Man Ship port lights look great. But very pricey.

[Bigjim]

Unfortunately, all the videos I watched and posts I read were installing windows and recommending butyl tape. Now I realize all those windows had metal frames that bolted to a metal trim ring. So, the interface was metal on metal and not metal on fiberglass or plastic on plastic.

I recently saw several other videos on installing plastic windows and they were very insistent on using a silicone-based sealant made for plastic, because other sealants could actually wreck the windows. Sheesh.

Anyway, I gave up. I pulled the windows entirely and replaced them with deadlights that do not open.





These will NOT leak, I guarantee it. One day, when I have plenty of time and money (ha!) I may try again with some metal windows. I've given up on plastic windows.