I started a med/large building today. It has the commercial tinted windows. Some of the smaller ones say fabricated glass heat treated on the bottom, the larger windows have no marks. The trouble I am having is on some of the windows I get them clean and if you look directly at them it looks like they have a zillion little water marks. I wet scraped them, scrubed the same spot for 5 min with steel wool, tried GG3 and Unger Pill, even scraped with the finger nail. Nothing took it off, not even a little bit. looking at them from any angle they look awsome, they "feel" smooth and clean. This is my first time on this building so I do not know how long the marks have been there. I can see from the construction debree the windows have never been cleaned correctly.
I would like to have an answer for the maintenance guy when I invoice it. What could cause this? Bad pressure washing? The tint is somehow making bubbles? Does not seem like hard water the steel wool would have removed most of that and there are no bodies of water within 20 miles.
Any ideas that I have not tried to remove it?
Thank you in advance for any responces, I can find 99% of answers by using the search option but this one has me stumped.