How to Have Sexy Windows !?

[Beersmith]

I am about ready to install some largish frameless acrylic portlights/windows on my boat and am looking for other people's experience with this particular type of installation.

I plan on following these instructions: Hints For Replacing & Sealing Acrylic Boat Windows | THE PLASTIC SPORK BLOG

it is sort of a modified version of the method that has been discussed here. instead of using the tape, it relies on the Sikaflex for the whole bond. The Sexy Windows article even mentioned in the updates that he might go this route of not using the tape.

My biggest concern was that the bond is only as good as the paint on the cabinside, so I plan on grinding off all of the paint under the windows so it will be bonded directly onto the gelcoat.

Of course the alternative would be to thru-bolt the ports, still using the Sikaflex with spacers. However, the methods in the links above are designed so that no fasteners are needed, which is where leaks seem to show up.

Has anyone had experience good or bad with bonding ports without fasteners or tape?

[elhix]

I stuck mine on with sika and vhb tape. I used the recommended primer under the sika and made sure to key everything correctly. So far - after two years - the lexan is still attached to the boat.

[Beersmith]

In the article he mentions:

he thickness of the bed is important. With the proper silicone I think a bed thickness of 2.5 to 4mm (1/8" + or -) for windows in the 300mm (1 foot) square size is more than adequate. The larger the window, the more the expansion, the thicker the bed of silicone required for success over time. Consult your supplier for recomended thickness of plastic. I used 3/16" (4.4mm) for the project shown. If using perspex/acrylic, I would have increased that to 8mm.

The tape is thinner than the recommended thickness of the sealant bed. How do you overcome this? Is there thicker tape?

[zeehag]

my boat uses teak frames and a lot of goober for the formosa windows--made of plexi , held in with wood and caulk .... they are gorgeous when installed tidily. the screws holding the wood to my coachhouse are what makes the clamp for the goober to hold the plexi in place---then there are plugs of teak to mask the sites of the screws so it is pretty .

[Capt Phil]

The sexiest windows I ever saw were on a Sport Fisher (Bertram, I recall) that pulled into the slip next to us in San Diego. The guys pulled off that night for parts unknown and left a lovely 20's something young lady to tidy up. She spent the week in just bikini bottoms cleaning the interior of the boat and would only put on her top to clean and washdown the outside. My wife wondered why I was up so early for coffee every morning! It was worth getting up every morning, believe me! Now those were SEXY windows! Phil

[Beersmith]

Hello all! My window project is finally complete, and they indeed look quite sexy!





I used a method of affixing the windows without the tape.

Full write up of my process here: Making and Installing Large Cabin Windows | The Quest for Wind and Waves

[KathleenB]

Hi Bob,

I came across your window article when searching the web last year. I have a Traditional 30 (Peter Cole design) and the windows were screwed on with silicon used for sealant. The overlap was only around 12mm and the windows perpetually leaked.

Following your instructions using the 3m tape and Dow Corning Sealant I had new polycarbonate windows cut by a marine window professional allowing a 25mm overlap. After filling all of the screw holes in the fiberglass with epoxy filler and repairing the damaged fiberglass I found the new window installation relatively easy and no more leaks even in 50knot headwinds and 3 Mtr waves with short fetch crashing over us for several hours on Port Phillip Bay.

I can attest to how great they look and how they are leak proof. Thank you for this valued information.

[UNCIVILIZED]

Looks like this is a thread/info to tuck under my bonnet for later use. Gracias guys.

[GRIT]

Any photos of finished products? If they don't leak by now, they'll never leak...old thread.
Great info.
Thanks.

[Ringmaster]

FYI, 3M UHB double sided tape is available on Amazon in quantities for normal people. Also available on Amazon is DOW 795 adhesive/sealant which is the only stuff that you should use bedding new acrylic windows.