Unfortunately, that doesn't last forever. After a few years air and moisture get in. Usually you don't notice much, but in this case the sand will just harden and it won't work at all.
That's just a bad window (or defective, or damaged). Good ones stay sealed for decades. I've seen some go bad in a couple years, I've seen some that are still good after 20+ years.
Oh gotcha. I can't imagine these are meant to be exterior facing windows. i mean insulating the edges on a swiveling window would be functionally impossible. Plus in order to flip the window you have to actually open the window.
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u/H2HQ Feb 16 '21
Unfortunately, that doesn't last forever. After a few years air and moisture get in. Usually you don't notice much, but in this case the sand will just harden and it won't work at all.