Replacing Lexan Ports on 23.5

[Forrest15112]

I have a '91 Hunter 23.5 and recently noticed the large ports on both sides are not sealed for several inches along the top. I had not looked in on it since fall and recently "found" several inches of water and lots of mildew waiting for me this spring. The large forward window has a good sized crack and a lot of crazing. Has anybody replaced these ports? From searching on here I believe they are bedded in Dow 795. The front has screws as well as the sealant. I am considering totally removing and replacing all with locally purchased acrylic/ lexan but am concerned about starting an encompassing project, especially since the large front piece will require heat bending. Any suggestions are appreciated.
Thanks.

 

[FastOlson]

If you have found a crack in one of the existing lenses, chances are your plastic is acrylic. Lexan is way different. Both have their advantages, but their properties are different.

You need a good adhesive sealant when you install those new lenses. When I installed four new Lexan (polycarbonate) lenses on our boat in '95, I floated each on a bed of sealant about 1/8" to 3/16" thick. This is absolutely vital because the coefficient of expansion of the Lexan is way different than your fiberglass boat.
(This would be true for acrylic, also, AFAIK.)

While other shipwrights will have good results with other sealants, I used Boatlife "LifeSeal" black, and it is still totally watertight. Good product.

L

 

[Forrest15112]

I've done a bit of Google'ng and saw reference to Lifeseal in other descriptions too. I'll definitely be looking into that. I also found this page that describes exactly what I want to do. I have resealed with silicone which will hold me over for a while until I decide (get the courage) to totally remove the current ones. Thanks for the info.

 

[Steve Dion]

I think you will find the proper product to reseal these port lights is DOW 795. It is a silicone based product that they use to caulk/seal windows into commercial buildings.

If you look at other Hunter (many other mfg too) they also use this product at the factory. Obviously good prep is important to get the surfaces ready for installation.

Most of the articles I have read indicate that you should NOT use screws. The trick that they use at the factory is to drill screw holes in the acrylic (not lexan) that are slightly oversized for the screws. The screws are only used during the curing process. Only the sealant is cured the scews are removed and the holes are filled with the product.

Our Hunter Vision has very large acrylic panels that have all secure with this method. I just re-did an area last year without removing the entire port and it has worked fine.

DOW 795 can be purchased from commercial outlets for about $7-$10 per tube. It also comes in several colors if that is important to you.