I finally tackled the leaking fixed ports this weekend. Removing the old leaking windows took much more effort than I had anticipated, but other than that, the entire project went well, and I managed not to stain the deck with too much black Dow Corning sealant.
Step 1: Remove old fixed ports.
The screws came out easy, but the sealant did not want to let go. As you can see, I didn’t manage to get either window off in one piece. Note that the factory method for mounting these windows required painting the edges and the center black, so that you couldn’t see the sealant through the window. However, that means you’re now bonding to the paint instead of the acrylic, so we decided not to do the painting. We also decided not to use screws.
The center sections were completely coated in sealant. While this made the old windows ridiculously hard to get off, it did nothing to actually keep them from leaking.
Step 2: Scrape and clean the mounting surface.
Step 3: Apply 3M mounting tape
Step 4: Level the new plexiglass window and pop it on the mounting tape.
Step 5: Mask around the freshly mounted fixed port.
Step 6: Goop it up with Dow Corning 795.
Step 7: Smooth the sealant into all the cracks, wipe up the excess, and then pull the tape and peel the paper off the plexiglass.
Step 8: Admire your new fixed ports that no longer leak when it rains.