This may be a topic for some other forum, but I was hoping some "glass and mirror" folks would be in here occasionally to try to answer this.
We have pretty hard water (mountains of limestone in the area). There's a film on the inside of the glass shower doors that won't come off. We've tried nearly every product that can be purchased with the same result. After one attempt by my wife, I remarked that the doors weren't coming clean, and of course, she said something like, "Well, it's your turn to try, then." We've alternated the cleaning and the product buying, but still the doors have a heavy film on them no matter what method or product either of us tries. I've even taken them outside and laid them across a corner of the deck railing so I can really bear down. The last time I used a Teflon pad with some stuff that was so caustic, I was having trouble staying close to it even when I was outside. Still no luck.
They look OK until they dry, then you can see a heavy film is still on the glass. I've tried scraping with a plastic scraper, and my fingernails - neither even makes a mark on the film. The door frames are brass plated, so we haven't used anything that will damage the brass finish.
Any glass folks out there know what's going on? Are these glass panels permanently etched?
The person who says it can't be done should not interrupt the person doing it. - CHINESE PROVERB