Ultra violet is the enemy of polycarbonate, and I have noticed some minor crazing on my windows. Infrared is the enemy of air conditioning, delivering BTUs I can't get rid of. Sunbrella lasts 20 years (with re-sewing every 5 years) in my expereince, so I sewed up some covers that snap on and off in moments. I'll be honest; I poached the idea from a Gemini owner.
A few tips:
- If the screw-snaps don't bite well, glue them in with 3M 5200. It is enough, will bed them, and they will still come out with a screw driver. The original screws on the PDQ were #10 but I could not find snaps larger than #8 nor figure out a reasonable way to fabricate them. I reason that the adhesive is what holds the windows and that the screw were only for installation.
- Always lube the snaps with some spray lube like Corr-Block or Bo-Shield. Repeat several times per year. The difference is incredible.
- Patterns can be made using freezer paper. Just trace the window and poke a tiny hole in the center of each screw that will become a snap. Allow for the hem. Some people preffer a vinyl edging, as Sunbrella is a pain to hem around curves. However, in my expereince the vinyl lasts about 1/2 as long as the Sunbrella, so we did the hems. You can also buy Sunbrella as an edging or tape.
- Sail Rite has the best prices on the snaps and fabric.
- This, from a sailor who tried Phifer-Tex instead of an opaque material, so that they would be see-through: "We used this and now will be replacing the windshield as the weave has left it's imprint, making visibility difficult. The windows were due anyway, but this accelerated the process and the weave is clearly visible in the plastic." Phifer-Tex is a plastic coated mesh, commonly used for cushion covers and sun shades; it is excelent in those applications.
- Laundering the covers a few times a year and waxing the windows at least once per year also helps. I'm too lazy to wax the boat, the windowns are well worth the time in terms of longevity and clarity.
- Label them with Sharpie, Bow Center or Starbord Aft, as needed. Always put the label in the same corner (top right).