Bullet-proof? Not hardly

 

Not even finger-proof

Well, now I have the answer.  

Remember way back, when I discussed Lexan vs. Plexiglass and postulated that polycarbonate (trade name: Lexan) would lose its properties when exposed to the sun over time? 

Well here is one of my polycarbonate storm windows, after 6 years exposure only in the winter, on the sunny side of Eolian in her slip.  I literally put my finger thru it when gently lifting it out of the slot today.  It is as fragile as a dry, dead leaf.  So much for 'bullet proof'!  And further, please look closely and note how the polycarbonate has crazed and browned up nicely where the port gasket did not protect it from the sun.

If you are changing/installing ports or hatches on your boat, specify acrylic (trade name: Plexiglass) instead of polycarbonate!  This is most important on hatches, where the possibility of someone standing on the hatch makes the choice of material a safety issue.

(One of the benefits of owning the same boat over a long time is the ability to do longitudinal studies like this.)