A Better Fix for Leaking Portlights
by Chris Gregory
Since commissioning my C36 in May I've been battling those Lewmar portlights and their leaks. These are the four that open, not the fixed ones in the hull. The temptation is, of course, to pop the plug off of the hatch dog and tighten the screw to add tension. This can make things worse, especially since it's important that both be more or less equal. One problem is that, due to the angle of the portlight, water tends to pool in the bottom.
After several months of fiddling with the tension on the screws, to no avail, I realized that the rubber gasket is, in effect, an O-ring. In the diving industry we use a lot of those things and lube them with what we call, "food grade" silicone. Last week I eased the tension on all for of my overtightened hatch dogs, cleaned the rubber gasket with water and a rag, and gave them a good, but not overly heavy coating of "food grade" silicone from my dive kit. The next day it poured rain and, with the exception of one portlight that was a shade too loose, none of them leaked!
This stuff is cheap, will not harm rubber products and is readily obtainable at any SCUBA shop. A little package the size of a half dollar will last for years.
Chris Gregory
1995 C36 MkII
"Different Drummer III"
Smith Mountain Lake, VA