Re-bedding fixed lexan Ports

[Tstein]

Aloha;

The lexan port is leaking and I'm trying to decide what is the correct product to use to re-bed? I plan to take the entire port out and clean off the "black-stuff".

I'm trying to figure if a polysulfide is what S2 originally installed?

Do you recommend any particular brand, Sikaflex, Boatlife/Boatchaulk?

Mahalo
Todd
S/V Engedi

 

[Bob McKee]

I have an S2 9.2A, several years ago I replaced all of the ports. I had new ones made at a Seattle plastics company and reinstalled them with galzer's tape. This is a neoprene tape with adhesive on both sides, I used 1/8" tape, but I think 1/16" would work just as well. You should be able to find it at a local glass shop. You need to predrill or cut the screw holes in the tape so that the screws don't wind up the tape. I installed the ports with SS screws and SS tee nuts. The ports haven't leaked in 3 years of Northwest rain.
I used this method because I couldn't stand the thought of the mess that rebedding the ports in seal would cause.

 

[BobM]

The original method is listed in the famous "S2 letter" from Tiara. Word to the wise, if you do use sealant be sure to mask the plastic then rough up the edges or you won't get a good seal. I looked at a boat with new ports that had just popped right back off letting wind and weather in. Boat is still listed on Yachtworld and the price hasn't even been reduced in a year!

 

[Maine Sail]

There are only

There are only three sealants that should be used on Lexan or Acrylic lenses. I'm guessing they are acrylic and not Lexan or polycarbonate as most all builders use acrylic.

The three sealants that really should be considered. Dow Corning 795 is the most popular but you can also use Sika Flex 295 UV with the primer & GE SG-4000.

Do not use general purpose polyurethanes or polysulfides on polcarbonates or acrylics..

This is a quote from Tony D'andrea the owner of Select Plastics the worlds largest hatch warranty, repair and rebuilding facility.

"Using the correct adhesive is only 1/2 the battle. Do not apply the sealants below 50 degrees F. The temperature must maintain at least 50F during the entire 21 day cure cycle. Cut this corner and your finished before you start. Preparation of the bond area is also very/ very important. DO NOT TOUCH THE BOND AREA WITH YOUR BARE HANDS! Contamination from the dirt and skin oils will make a solid cure impossible. You may clean the FRP and metal with acetone to prep the area but if you touch the Lexan or Plexi with harsh solvents you will ruin the portlight. A 50/50 mix of isopropal alcohol and distilled water will work well to clean the plastic if needed. Remember that clean enough is not clean enough."

 

[BobM]

http://www.angelfire.com/mi/loosecruise/S2/13pageletter.html

Contains info from the manufacturer about S2's including port replacement instructions.

 

[Calypso]

Eventually I'd like to replace three of mine as they are all crazed. My opinion is 100% silicone. I believe dow 795 is/was silicone. West marine's catalogue for our Beckson ports says "100% silicone only" I was surprised and happy as silicone doesn't say marine on the label and is reasonablly priced.