I just bought a new 15th floor unit that had incredibly dirty windows. They probably had not been cleaned in over 20 years. I hired a professional window cleaning service and, after they removed all those years of dirt and grime, the windows still look terrible. The cleaners told me the glass is stained from years of acid rain erosion on the building's limestone running over them, and there is... [more]
I just bought a new 15th floor unit that had incredibly dirty windows. They probably had not been cleaned in over 20 years. I hired a professional window cleaning service and, after they removed all those years of dirt and grime, the windows still look terrible. The cleaners told me the glass is stained from years of acid rain erosion on the building's limestone running over them, and there is nothing they can do. I have read up about this and it seems like a legit problem (not just the window cleaners being lazy). A common solution I have read is to create a mixture of 50% water, 50% white vinegar, spray it on the windows, let it sit a while (I guess you need to keep spraying it or it would just dry after a few minutes), and then use a razor blade to scrape off the stains. It is a long and tedious process, but the websites I have read claim that it will work if you are patient. I have 24 oversized windows in this unit, so that would require a lot of patience. For various reasons, just replacing the windows is not a viable option.
Has anyone else had this problem before? Have you had any success cleaning the stains off with this method or any other? Any good recommendations of window cleaners willing to do the work?
Thanks.
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Response by alanhart
almost 13 years ago
Posts: 12397
Member since: Feb 2007
Try a product that's made for removing lime scale, which is common in most parts of the country, but not NYC (hard vs. soft tap water). Test a small count first.
One product is called something like CLR, for"calcium lime rust". HD or hardware store.
I suspect anything too acidic or basic will etch the glass.
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Response by Primer05
almost 13 years ago
Posts: 2103
Member since: Jul 2009
I find this all the time and generally we get new glass installed
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Response by mikewalkerman
almost 13 years ago
Posts: 25
Member since: Apr 2012
Thanks Alan and Primer. Primer, I looked into having the glass replaced. It doesn't look viable because (a) due to the size and number of windows, it would be extremely expensive ($35-40k), and (b) this is a co-op and a landmark building, so getting board and DoB/landmark commission approval would take months and be a nightmare (I am told that others in the building have tried to change thier windows in the past to no avail). So I'm afraid I am stuck with these ones.
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Response by kharby2
almost 13 years ago
Posts: 279
Member since: Oct 2009
My doorman's dad was a window washer, and our doorman usually cleans the windows for people in our building--they are the dropping into the room kind. He told me he uses oven cleaner to good effect on severely stained windows. You can get more eco friendly oven cleaners nowadays, definitely need hand protection.
Also, if you have screens be sure to replace with the non etching kind (I think they are fiberglas or acrylic, I can't remember just now).
Don't ever mix chemicals, but another thing I would try is cleaner designed for granite. DuPont makes an excellent pleasant heavy duty granite cleaner. Just a hunch of have from using the stuff on granite and marble.
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Response by jelj13
almost 13 years ago
Posts: 821
Member since: Sep 2011
Several people in my building had similar problems, so the Board sent out window cleaners with a "special spray". I untaped the paper wrapped around the discarded spray cans and found they were using old fashioned oven cleaner (not eco-friendly). Oven cleaner really restored the windows!
Try a product that's made for removing lime scale, which is common in most parts of the country, but not NYC (hard vs. soft tap water). Test a small count first.
One product is called something like CLR, for"calcium lime rust". HD or hardware store.
I suspect anything too acidic or basic will etch the glass.
I find this all the time and generally we get new glass installed
Thanks Alan and Primer. Primer, I looked into having the glass replaced. It doesn't look viable because (a) due to the size and number of windows, it would be extremely expensive ($35-40k), and (b) this is a co-op and a landmark building, so getting board and DoB/landmark commission approval would take months and be a nightmare (I am told that others in the building have tried to change thier windows in the past to no avail). So I'm afraid I am stuck with these ones.
My doorman's dad was a window washer, and our doorman usually cleans the windows for people in our building--they are the dropping into the room kind. He told me he uses oven cleaner to good effect on severely stained windows. You can get more eco friendly oven cleaners nowadays, definitely need hand protection.
Also, if you have screens be sure to replace with the non etching kind (I think they are fiberglas or acrylic, I can't remember just now).
Don't ever mix chemicals, but another thing I would try is cleaner designed for granite. DuPont makes an excellent pleasant heavy duty granite cleaner. Just a hunch of have from using the stuff on granite and marble.
Several people in my building had similar problems, so the Board sent out window cleaners with a "special spray". I untaped the paper wrapped around the discarded spray cans and found they were using old fashioned oven cleaner (not eco-friendly). Oven cleaner really restored the windows!