UV seems to be the factor which destroys the Gray Enterprises portlights. Anybody have any luck painting them? Could be a simple solution to a common problem.
Per my attached pic, yes I have painted the exterior frames. When I bought the boat 8 years ago, hairline cracks were minimal and the original caulking seemed to be doing it's job of keeping H2O out. But the exterior frames were very oxidized and the old plastic did prove to be brittle... evident if say a misplaced step ended up on part of the exterior sections that protrude out.
Seven years after my first painting, the exterior frames are still the same. That is no further degradation and still not leaking.
But note: My boat is in California. Although a lot of UV around, we have low humidity and a cold spell is 28-35F only at night and only for a few days a year at most. Besides UV damage, I am probably right in guessing that the decades ago plastic formulations became brittle also as a function of age. Like my new new in 1986 (or thereabouts) ski boots that only were used a few days per season. In between they were stored in a nice dark closet. 7-8 years later when making a turn over a mogul, one of my skis was no longer with me. I just thought that the binding had released prematurely. Climbing back up the hill to retrieve the ski was I amazed to see that the entire sole of the boot was still between the toe and heal parts of the binding. The sole had simply broken away from the rest of the ski boot! That would not happen with today's ski boot plastics.
The Gray Enterprises clear or smoke port lenses, at least the ones made say 10 years ago, also degrade quickly in UV. I know because BoatsUS stores were going out of business (absorbed into West Marine) at the time I bought my boat. In stock at the local store they just happened to have four of the replacement port kits that fit my boat for 25% of list. Since my existing frames were good enough, I just replaced the old probably 25 year-old lenses with the new smoke color lenses from the kit. About 4-5 years on, they already had started to become cloudy. Maybe the more recent formulations of clear or smoke plastic will do better?
Regarding painting. Since the old frames are oxidized and pitted, paint adheres very well. Use a 3M abrasive pad to "dust" off the surface oxidation. Then clean with acetone. I used a paper hole punch on masking tape to make lots of little dots. Put the dots over the screws on the outside of the frames to prevent build-up of paint in the phillips head recesses which will be a benefit for the day when the frames do need to be removed and replaced. Leave the dots on after the painting. My dots are still in place after three paintings. Mask around the frames to prevent paint from getting on the cabin top gelcoat. My paint of choice has been Rust-Oleum's Hammered finish. It lasts about three years. After the second year, I aggressively scrub with a coarse terry cloth towel which removes much of the surface dullness. Good enough anyway to allow another year or so before the next need to paint. Don't wax between paintings. Unless one is a diligent/frequent waxer, I doubt waxing will do much to extend the life of the paint. But wax would sure make surface prep for the next painting much more difficult.
