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From the Technical files of S2 Yachts



We are unable to manufacture the plexiglass windows for our S2 sailboats. These plexiglass components are made from a material known in the industry as Lexan. Your best bet for replacing these windows is to make paper patterns of them before removal, then remove the window and have a replacement made from your paper patterns. The windows on most S2's were simply cut from flat stock. We suggest making a paper pattern first because these windows are bonded in place and will probably come out in several pieces. The windows were made from bronze tinted lexan. If you do not know who works with this material in your area, you can contact your local auto glass facility. If they do not work with lexan they can refer you to someone who does.


Keep in mind that these windows will be difficult to remove, and will probably break into pieces. Pattern making from the originals should begin before the windows are removed from the boat.


The seals around our cabin windows are often mistaken for preformed gaskets. The sealant used is Dow 700 industrial grade silicone caulk; this is available in a few different colors (equivalent brands are more than likely available in your area).


Here is how we installed the window's originally. We took a plexi window with the outer surface covered entirely in masking tape, and set it temporarily in its opening. Next we shimmed it (only if necessary) to ensure it would be flush with the surrounding fiberglass. We masked off the surrounding border of the opening and drew "cross hairs" on the masking tape (both on the window and the surrounding mask) to aid in alignment while installing the window with sealant. The perimeter of the window's surface (that comes in contact with the opening) was then roughed up with 80 grit sandpaper. Take care not to scratch any portion of the window that you will be "looking" through. With the window removed, both the opening perimeter and the edges of the window received a generous bead of black silicone caulk. Here comes the Chinese fire drill; the window was literally mushed in place from the outside, while someone inside the boat armed with a putty knife and lot of rags, caught the oozing caulk and wiped it on rags.


From the outside, once the Window was in flush with its surroundings and aligned with the cross hairs, a plastic scraper was used to scrape all the outer ooze off flush with the window and cabin house. The caulk was then allowed to cure for twenty-four hours. The thicker the bead of silicone, the longer it needs to cure, and it will take a while before the entire seal is cured all the way through. The masking tape wasn't pulled off until after the twenty-four hours elapsed.


If you just need to make your seal look pretty again, dig out the outer layer of sealant. Mask off, over fill with silicone and level with a plastic scraper. Now, the people that did this on regular basis did not really need to touch up the caulk much to make it look pretty. Nevertheless, if it does need to be touched up, here is what you do. You will need a small container of water, more rags, and more black silicone. Apply the silicone where you need it and then dip your finger in the water, smooth the caulk, wipe your finger on a rag. Re-wet your finger, smooth seam, wipe finger on rag, repeat as necessary. You may elect to do this step while the masking is all still in place.



Things to Remember:

#1. If you skimp on the caulk, you will end up with either air bubbles, voids in the seal or both.

#2. Silicone does not stick unless all the surfaces are clean and dry.

#3. Don't let someone talk you into using something other than silicone The thermal expansion and contraction rates are drastically different between the plexiglass and the fiberglass. So elasticity of the cured sealant is critical. Your elastomeric, poly-sulfides are better adhesives (remember cleanliness when using silicone). But, they cure hard and cannot expand and contract with the changes in temperature.

#4. Keep solvents away from plexiglass, Lexan, and acrylics. They will craze plexiglass and speeds its degradation. Even Windex has NO PLACE on or near these polycarbonate materials. For general cleaning, furniture polish like Pledge is your best bet. For more serious cleaning use denatured alcohol.


Opening Portlites came from Beckson Marine. Beckson references their ports by the size of the lens. The model number used on the 7.9 was : POSD-0,1” The 1” indicates the maximum cabin wall thickness that this unit can be mounted to. Parts for them as well as entire units are available direct from Beckson. They may be contacted at:

Beckson Marine

165 Holland Avenue

Bridgeport, CT 06605



Note on Cabin Side Windows