After several months of testing the panels, we established some preliminary findings regarding different vinyl brands. The untreated Strataglass, OSea, and Regalite panels were equally clear; there was a slight difference in their coloring, but this is typical and in use, it would never be noticed.
While heavier grades (40 mil) of vinyl are stronger and stiffer-a structurally important characteristic in large windows-we found that the wavering common to vinyl windows that are not perfectly flat is far more noticeable in the heavier materials. Strataglass is noticeably stiffer than OSea, which is in turn slightly stiffer than Regalite, in both 30-mil and 40-mil thicknesses.
Testers noted that the 30-mil material is much easier to roll than the 40-mil and is presumably less prone to cracking in cold weather, though we have inadvertently cracked older 20 mil materials in extreme cold. We believe 30-mil material is a better choice for applications where vinyl windows are of reasonable size and visibility is very important, such as forward-facing windows under hardtops, smaller dodger windows, and windows that are often rolled-up. (Thinner material is less prone to scratching when rolled.) In these applications, the durability of the lighter product is equal, according to canvas makers and vinyl manufacturers we talked with.
Even lighter products-20 mil-are commonly specified for small powerboat enclosures that are frequently rolled up and stored; though 20 mil does not hang as well as 30 mil, the windows store more compactly.
We will be comparing OSea to Strataglass over time. It seems that the OSeas greater flexibility would be an advantage in many applications. However, the product is newer (2009) and is still gaining market acceptance.
Hazing can be caused by prolonged high humidity. While a brief or even all-day rain won't cause this, a good noreaster or life in the Pacific Northwest can result in vinyl hazing due to water absorption. In drier climates, hazing is generally only noticed when a window is rolled up when wet. You can see through a humidity-hazed window, but the world appears to be wrapped in a fog. In our testing, coated products-OSea and Strataglass-were very resistant to this effect. We treated the uncoated products-Regalite and Crystal Clear 20/20-on both sides with several different protectants, and while there was some improvement-creams performed better than spray cleaner/protectants-hazing was still much greater than with coated vinyl products. Testers also noted that this vulnerability increases as the vinyl ages and after its polished with a scratch remover. The panel that fared the worst was a new, uncoated sheet that had been polished to a nice shine with a fine compound but not waxed; of course, in the real world, users would apply wax, but wax wears off.
Testers also observed that the OSea and Strataglass have a slightly greater resistance to scuffing than their uncoated versions, Regalite and Crystal Clear 20/20. However, none of materials offer any significant resistance to sharp metal objects, sand, or salt, and all received a few scratches during handling and mounting. Manufacturers claim resistance only to fabric and other soft materials.