leaky frameless windows in topsides

[phorvati]

I am looking for advice on how to approach fixing leaky hull windows. Boat is shrink wrapped for the winter. I have most of the windows removed and core around the frame cleaned out and drying. It was wet.
Just looking at how it was done, i fear the frameless exterior approach has no chance of being leak proof. If i chose new ports with exterior frame and interior frames, I will have to cut off sections of teak rub rail around the opening which I would like to avoid.

[DeepFrz]

There is one particularly good thread on the forum about installing frame-less windows. A "google custom search" should find it for you.

[neilpride]

I fix a bunch of those frameless leaky Windows in some Beneteaus, personally i dont like it , i use Sika primer and the proper Sika polysulf, very similar if not the same as the OEM approach, im not sure if yours are plexi just bonded in the exterior or?
Prep is the key, so far the last salóon Windows in a 50 ft bene are still strong...

[phorvati]

Thank you. Originals were glass, but there was an attempt by one or more POs to fix the leak. A very crappy job. And some of them are now either poly-carbonate or might be lexan. I dont see evidence of Sika primer. I'll look for the thread. Its really scary when designer chooses to add hull ports and does it in a way that eventually introduces a waterlogged hull.

[bcboomer]

I can't imagine any way to reliably and permanently seal a flush window. I'd bite the bullet and put in New Found Metal portlights.
If you follow the installation shown by Maine Sail you can forget worrying about leaks. As a bonus you can open them for lots of fresh air.
I believe you have a balsa cored hull. If so, hopefully the portlight openings were isolated during construction.
Mine weren't and it was quite a challenge to get out all the damp balsa and replace it.
A sleek hull looks nice but not as nice as a leak proof one.

[zeehag]

formosa windows have no frame. they are plexi in a hole with a wood piece goobered onto em then screwed into the coachhouse. lotsa goober is best--where i am i use sikaflex yellow tube.
my coachhouse is wood, so it is easier to repair

[CaptainLen]

If your windows are lexan as mine are you can easily construct an accurate shape and depth bed in the topsides and seal in replacement windows. I used small washers between the window and the bed so that the sealant provides some flexibility for movement. I believe the sealant product I used years ago was DOW695 but Tony at Select Plastics in CT can confirm that for you. He can also fabricate replacement windows if you send him your old ones.

[phorvati]

Originally Posted by bcboomer

I can't imagine any way to reliably and permanently seal a flush window. I'd bite the bullet and put in New Found Metal portlights.
If you follow the installation shown by Maine Sail you can forget worrying about leaks. As a bonus you can open them for lots of fresh air.
I believe you have a balsa cored hull. If so, hopefully the portlight openings were isolated during construction.
Mine weren't and it was quite a challenge to get out all the damp balsa and replace it.
A sleek hull looks nice but not as nice as a leak proof one.

All that sounds good, I would just hate to add more work for myself. I would have to take off the rubrail and cut off sections of it to allow for exterior frame. On the other hand its not excluded that the teak rubrail is introducing water int he hull as well. Rubrail is just lag-bolted in.

[dick sargent]

To allow for expansion and contraction, drill fastener holes slightly oversize so a surgical rubber sleeve can be included on the fastener.

[Seighlor]

"To allow for expansion and contraction, drill fastener holes slightly oversize so a surgical rubber sleeve can be included on the fastener."

Please provide a bit more detail on how this is accomplished.

[bcboomer]

Originally Posted by phorvati

All that sounds good, I would just hate to add more work for myself. I would have to take off the rubrail and cut off sections of it to allow for exterior frame. On the other hand its not excluded that the teak rubrail is introducing water int he hull as well. Rubrail is just lag-bolted in.

Looking at your picture I'd router out an inch of core, fill with thickened epoxy, and use UHB to retain the acrylic. You'd have to modify the typical surface mount technique but it should result in a pretty durable seal.
I hate using screws to hold the acrylic because it gives a bunch of potential leaking/cracking points.

It would be great if you could post a few pics as you progress.

[maine50]

Pretty sure I don't want opening ports in my hull and would advise people of the risk which should should be obvious. Not even a big fan of putting fixed ports in hulls, but I understand the appeal of that.

[UNCIVILIZED]

Originally Posted by Seighlor

"To allow for expansion and contraction, drill fastener holes slightly oversize so a surgical rubber sleeve can be included on the fastener."

Please provide a bit more detail on how this is accomplished.

You insert a rubber sleeve that's slightly over-length, & when the fastener is tightened, it gets compressed. Which causes it to bulge around it's entire circumference, thus sealing things.

For the portlights, you could remove a fair bit of core around the window, replacing it with solid laminate, or laminate & G-10. And then inlet the laminate from the outside either for; a structural trim ring, an opening port, or for the glass itself. Which should let you bolt it in place, with or without a trim ring or frame, & have it remain watertight for a time. This, while everything is recessed below the top of the outer skin of the hull.

Just ensure that the laminate is both sufficiently thick, & has superior bonds to the hull laminate, since it'll be very much structural in nature. To perhaps even hold the glass from being pushed inwards when the boat falls off of waves onto her topsides.

Also, you can tap G-10 for fasteners, so that it acts as any or all of the following; structural laminate, washer/frame, nut. Though I'd probably want to use washers, & nuts on the fasteners in this application.

One other approach would be to remove the core in a large area around the opening in the hull. Then bond a drilled & tapped metal frame in place inside of the hull. Followed by applying 20mm of laminate over top of it. After which you’d reinstall the glass, on top of a gasket, then topped by another gasket, with a metal frame bolted over top of everything from the inside.


BTW, you needn’t remove the rubrail from the hull in order to trim it down in the vicinity of the holes for the ports. Or anywhere else for that matter. It should be pretty easy to cut & shape it in place, using any number of hand or power tools. Why do you see this as problematic?

All sorts of routers, bits, & jigs would facilitate making quick, accurate work of this. Ditto a few types of hand saws used for precision carpentry, along with chisels, etc.

PS: I too would avoid putting opening ports in a boat's topsides. The results of an error on someone's part, or a failure of any component of the port, could have a price that's just too big. Meaning if it gets left open, un-dogs itself, or breaks. The glass, or the frame.

Also, if you've got the time, it'd probably be worth it to add a metal strip on top of your wooden rubrails. Call it dock armor.

[carlo de leo]

I have a cold molded epoxy boat with those kind of portlights. If possible, consider leave a margin for the contraction/expansion of the window material (acrylic or policarb). Otherwise, Sika won't be able acomplish the variation. The margin witdth depends on the surface area of the window, this case I would say 5mm (just a guess).
Good luck
S/V Gulliver II

[dick sargent]

Originally Posted by Seighlor

"To allow for expansion and contraction, drill fastener holes slightly oversize so a surgical rubber sleeve can be included on the fastener."

Please provide a bit more detail on how this is accomplished.

"Slab-on" is the term I use to describe the window installation I used on my 44' Countess sailboat. The fasteners should not be countersunk without using trim ring washers. I replaced four 2' x 4' windows in the deck house with lexan. At that time, the method was used for windows in pressurized cabins of aircraft. The windows have been leak proof for 25 years, 20 of those years included being forcefully awash at sea or daily rain storms while in Central America. Didn't know about butyle ? tape so I probably used sikoflex or 3m 4200. I hate lexan. Scratches easily and loses its strength over time. If doing it again I would use other materials; including glass. Interestingly, one study maintains that vessels "falling off" storm waves cause the most catastrophic window breakage. Some consolation huh. Lol