Glass vs plastic deadlights
I would NOT go with glass for anything that might see actual seagoing use.Lexan is theoretically unbreakable under even extreme seagoing circumstances (1/2" stops a .38 bullet-- so I am told). There are varying grades of Lexan-- some are UV-resistant and therefore would last a long time before yellowing. Count on many boatbuilders especially in the '70s to have used cheaper stuff. At Cherubini we had problems getting good Lexan for the skylights-- it would have bubbles inside it (since all acrylic is essentially in a liquid state). They took away nothing from practical strength but looked awful. The plastics guy tried to blow it off-- 'well, I could see it if it were a museum showcase.' I said, 'Buddy, for all your practical purposes a two-hundred-thousand-dollar boat IS a museum shoecase!' The moral: don't compromise about what's right-- just insist that you get it.Plexiglas is breakable but it is better optically-- if flat it does not distort (the Germans sanded the curved corners of Messerschmidt fighter-plane windows so the pilots would not look through the distorted parts!). Lexan is the seagoing sailor's choice. The deadlights (non-opening) on something like an H-27 should be about 3/16" or 1/4". Bed them with 5200 or some other sealant. The 5200 is made to give with the temperature changes of plastic-to-plastic. I don't know about glass (and it's NOT good for aluminium).As far as safety glass goes-- if it did break, then what would you do? Think about under what conditions it will break (because it's WHEN, not IF). Do you want broken glass pebbles in your bunk and a gaping hole open to breaking water in THAT weather? And how would you fix it? --with plastic you could drive sheetmetal screws right into it to fasten a patch-- if it broke at all.Remember, it's a boat, not a porch.JC 2