really dirty window
October 22, 2010 7:14 AM   Subscribe

we have an apparently leaky double paned window, with a strange white residue on the insides of the panes.

My husband dis-assembled the window and tried to clean the residue (what a guy!). Vinegar, CLR, Car Polish, and a few other household cleaners did not work! scraping witha a blade worked but the residue covers the entire window, and this tactic would take too long. What is it, and how do we clean it? Thanks Metafilter!
posted by hollyanderbody to Home & Garden (11 answers total) 1 user marked this as a favorite
hard to say without seeing it, but it's probably runoff from the exterior building materials - concrete, limestone? as an ex-windowcleaner, i can tell you that if clr didn't do it, you'd likely be talking acid to get that off, which is nothing you want to do yourself. if i were you, i'd stop at a janitorial supply house (home depot?) and get a wide-bladed scraper, since scraping apparently worked.
posted by facetious at 8:27 AM on October 22, 2010

also could be deposits from metal window screens. same situation.
posted by facetious at 8:27 AM on October 22, 2010

last post. if you really want to diy, try oven cleaner (gloves, mask). just for 20-30 seconds, rinse the hell out of it with fresh water. might burn/ruin the glass.
posted by facetious at 8:30 AM on October 22, 2010

What you've got there is some kind of mineral deposit. This site suggests using Goof Off, which doesn't strike me as being a bad idea. But scraping may be your best bet.
posted by valkyryn at 8:30 AM on October 22, 2010

You can try some stronger solvents, but once you get into that world of chemicals, you're going to need to be very strict about safety precautions. Chem-lab grade protective gloves, safety goggles, breathing masks, do it outside, keep a source of flowing clean water nearby in case of exposure...

Anyway, now that I've sufficiently scared the pants off of you, here are the chemicals that I think *may* have a shot at cleaning your glass. I'm pulling this totally out of my nether regions, given that I have no idea what it is that you're tying to clean off. And remember, be careful with this stuff! Don't let your husband send himself to the hospital.

1. "Mineral spirits". Available at the hardware store, generally used as a solvent for different kinds of paint or other stuff that you spread on walls. Smells pretty bad.

2. "Hull cleaner". Used to melt barnacles off of the fiberglass hull of a boat. *Very* strong, do not breathe this stuff in. Available at marine/boating shops.

There's very little that won't budge under those two. However, if that doesn't work, I think that you're stuck with scraping it off with a blade. I was going to suggest a third option of caustic lye if they didn't work, but that's even more dangerous to handle, and it can react with the glass surface.

Good luck!
posted by Citrus at 8:40 AM on October 22, 2010

As a professional glass worker I can with near certainty say it won't come off. I had this exact problem this week, but with tempered glass. Had to order new glass.
But even if he does get it off, the unit is trashed since the internal desiccant is probably shot and without a bit of know-how and tools makng your own sealed IG units is a total pain. Sorry.
Ps. Pure ammonia is the ultimate cleaner, but try it last because it's so intense.
posted by princelyfox at 8:48 AM on October 22, 2010 [1 favorite]

Oh, forgot to mention that these rarely last more than 30 years. I don't know how old yours are.
posted by princelyfox at 8:49 AM on October 22, 2010

As I read your question, this white deposit is on the inside surface of one or both panes between the two panes of glass, and therefore the other answers, except for princelyfox's, wouldn't seem to apply.

Double-paned glass is typically sealed at the edges with some kind of tar or pitch. The white deposit is probably a volatile component of this sealant which has condensed on the glass after many, many cycles of heating and cooling, most likely from direct sunlight.

You could confirm this by taking two hair dryers and heating one of the problem areas inside and out simultaneously. If I'm right, that should make the area you heat clearer, but may make another unheated area worse.

I've heard that there are companies which repair this problem, but I've never tried to deal with them. My friends who had a very similar problem just replaced all the affected panes. I would see what I could do with hair dryers and or heat guns if I were you before I resorted to replacement, but be sure to wear safety goggles if you give that a try.
posted by jamjam at 11:20 AM on October 22, 2010

Just chiming in to say that we have the exact same problem with some of our windows. If it's the same as ours, the white residue is solid, flakes off in places, and is on the inside of the window, between the panes. The progression for our windows was moisture condensation between the panes, then solid white residue about a year or so later.

I don't know how to fix this, but I did ask a window shop ant they told me they could replace the glass in the windows and re-seal them for about $100 (this is in NYC).

Not to derail, but how did your husband open up the window?? And was he able to put it back together again?
posted by agent99 at 11:36 AM on October 22, 2010

I should have been clearer. Whether or not the residue comes off, the fact that it's there shows that there's a faulty seal on the unit. Insulated Glass units are actually sealed with silicone and have a desiccant in either the metal or foam edge that keeps the air free of moisture, which is the root cause of whatever's happening to the glass (it's devitrification). New windows use intert argon gas in there.
posted by princelyfox at 5:46 PM on October 22, 2010

Response by poster: To open it he took it out and removed the outer frame and rubber cushions, then found where the seal between panes wasn't stuck anymore, slipped in a butter knife and worked it around the window. Yes he got it back together and we know it isn't sealed (hasn't been for years apparently). Replacement is the obvious fix, but he was just trying to make it clear for now.
posted by hollyanderbody at 6:26 PM on October 22, 2010

« Older Unfairly Fired by Feds   |   Weekend in Colorado Springs Newer »
This thread is closed to new comments.