JFowler
Active member
Interesting information- thanks.
Silicone Sealant for new Portlight Seals??
- Thread starter JFowler
- Start date
jigray3
New member
I have replaced my 30 year old size 1 and size 4 Lewmar Old Standard port lights sold up until about 1999 with the current New Standard MK 3 version. The new ones have only 1 seam in the outer frame and it's vertical and on the bottom of the frame in a typical horizontal application. The new joint is filled with Boston Stimson ISP 70-03 rather than a plastic spacer, seems to be impressive stuff and that info is closely held by Lewmar. The new ones also have no holes drilled in the Lexan at all. I felt like these changes were improvements, eliminating possible sources of leaks, but time will tell. Also, Because hinge and closure hardware is adhered to the Lexan, replacing a crazing lens will certainly be more expensive down the line. Another reason I replaced them is spares are becoming difficult to find for the Old Standards, especially the EPDM lens to frame gaskets, which are unique.
If replacing Old Standards for New, be aware the radius of the corners of the New ones are larger making them appear more rounded. The length and width of the cutouts are the same, and the new ones should fit the cutouts, but you'll find there's not a lot of bearing surface overlap at the corners. If your cutouts were well and precisely made you should be fine, but if the cutouts are poorly cut and sharper at the corners than necessary, it may be necessary to repair the fiberglass and gelcoat in that area to make the cutout smaller so the outer frame of the port has a backing surface to bond to. Unfortunately, you won't know what you're dealing with until you remove the existing port lights.
If replacing Old Standards for New, be aware the radius of the corners of the New ones are larger making them appear more rounded. The length and width of the cutouts are the same, and the new ones should fit the cutouts, but you'll find there's not a lot of bearing surface overlap at the corners. If your cutouts were well and precisely made you should be fine, but if the cutouts are poorly cut and sharper at the corners than necessary, it may be necessary to repair the fiberglass and gelcoat in that area to make the cutout smaller so the outer frame of the port has a backing surface to bond to. Unfortunately, you won't know what you're dealing with until you remove the existing port lights.
geem
Well-known member
We tried butyl tape. It's a nightmare in the Tropics. It flows out of any joint where it is under slight compression. It then sticks to your clothing or what ever is nearby. Never again in a hot climate.