Our boat has Lexan windows and in spite of its strength. Lexan is prone to scratches and requires special care. When salt water dries, it leaves crystals behind. Therefore, to avoid scratching of the Lexan, you must use lots of fresh water when cleaning.
I add a squirt of biodegradable, gentle dish soap to a bucket and fill it with fresh water. I use a new microfibre cloth that has not been used to clean anything before and cut off any seams or tags. Hose down the windows first, then slop on the soapy water – do not scrub. Rinse thoroughly and repeat if necessary. I let the Lexan windows dry naturally and open the hatches so that the water runs off and doesn’t leave water spots.
Some people suggest using a non-abrasive toothpaste to clean Lexan, but I have not tried this. If you have a spare piece of Lexan, I suggest testing a small area first before cleaning your windows. There is a lot of information available online and I found an interesting dialogue on Cruisers’ Forum that you might want to read.
Cleaning the inside of the windows is a little more challenging since you can’t spray the inside of your boat with a hose. Do your best using as much water as possible without making a mess. No Windex and paper towels or your Lexan windows will deteriorate.
The previous owners of our boat suggested using carnauba wax on the windows to add a protective layer to the Lexan. A friend who is a glazier/sailor suggested using liquid wax. After cleaning and allowing the Lexan to dry completely, I apply the liquid wax in small sections – wax on, wax off. Follow the instructions on the product label and do not apply on a sunny day. The wax will fill in fine scratches and provide a protective layer. I wax the windows twice a year: at the beginning of winter and at the beginning of summer.
Crazing will occur over time from exposure to sunlight. We installed new Lexan windows on our boat and used screws with snap heads so that we could put Sunbrella covers on them. We are not hermits and like to see out of our beautiful windows, so we tend to cover the pilot house windows on the side of the boat that we board to protect them from zippers and buttons from pant legs. The snaps will need cleaning to keep them free of salt deposits and rust. If the snap heads are tight when removing the window covers, use the flat edge of a knife being careful of course, not to scratch the Lexan.
- Clean using lots of fresh water and mild dish soap.
- Use a clean, soft cloth.
- Protect from sun and accidental scratches.