Protecting Clear Vinyl Windows

Whats the best way to prolong the life of Strataglass?


When we last tested clear-vinyl window protectants (PS, March 2009), we raised the concern that some products might actually damage the vinyl. PS tester Drew Fryes recent work with mildew cleaners (PS, November 2013) brought up another concern: Can overspray from canvas cleaners and treatments, or other common chemicals, damage the clear-vinyl windows?

Since PS testers are now in the process of long-term testing Sunbrella water repellents and clear-vinyl window protectants, we decided it was an opportune time to also experiment with canvas water-repellents, cleaning chemicals, and common cockpit chemicals to see whether any overspray would damage Strataglass. While several had no effect on the Strataglass, a few totally ruined the window sample.

How and What We Tested

Testers sprayed test panels of Strataglass 40 (flexible, clear vinyl window material) with 11 cleaners, canvas water-repellents, and other chemicals commonly used on boats. They allowed the Strataglass samples to dry, then washed them off with a mild soap.

The test field included four canvas waterproofing treatments: Mary Kate Fabric Waterproofer, Iosso Water Repellent, Star Brite Waterproofing with PTFE, and Aquatech Water Repellent. Common cleaners tested were Windex, ammonia, and a vinegar-water solution. Testers also included Goldshields GS5 (PS, November 2013), a spray-on antimicrobial we previously tested as a mildew preventative, and RainX, which is recommended for glass and hard plastics only. Rounding out the test roster were two common boating accessories: DEET mosquito repellent (REI brand) and sunscreen (No-Ad SPF 40).

What We Found

The products that showed no ill effect after one application to the Strataglass were the Windex, RainX, ammonia, the vinegar-water solution, and the Mary Kate, Iosso, and Star brite waterproofers. The No-Ad sunscreen resulted in some minor window fogging, but testers were able to buff away the fogging with a little elbow grease.

The Aquatech canvas treatment and Goldshield mildew repellent both damaged the clear vinyl, but not nearly as badly as the DEET bug spray. The Aquatech caused enough fogging to ruin the window, and the Goldshield left some serious waterspots that ruined the Strataglass sample. The DEET bug repellent actually melted the Strataglass, and the window sample remained sticky for weeks.

Bottom line

Keep in mind that the test results are only the single-use, short-term effects. As vinyl-window manufacturers will tell you, none of the products we tested (except perhaps the vinegar solution) are approved to use on flexible vinyl windows, and with regular use, all will lead to fogging and damage in the long term. Makers recommend only a few vinyl treatments and the gentlest of cleaners, and none of the things tested on this list. Yet, there is always a risk that accidental product overspray or sunscreen/bug repellent-coated hands will find their way to your Strataglass, so we thought youd like to know what the result is likely to be.

Frye removed Windex and ammonia from his boat years ago to prevent a disaster at the hands of a helpful crew member. Still, every summer someone puts a sunscreen handprint on a window somewhere, while helping to roll them up. He cautions every user of bug juice to spray downwards, downwind of any vinyl windows, and keep hands far from the vinyl. A better bet would be to use only DEET-free bug repellent on board, but even those products may harm clear vinyl.


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