Low-e? “Do not scrape glass.”
willgoodwin
| Posted in Energy Efficiency and Durability on
I just installed some high end french doors that came with a sticker warning ‘DO NOT SCRAPE GLASS”. Does anyone know anything about this? Is it some new kind of low E film, have there been long term problems with scraping low E glass?
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Replies
William,
It's possible that it's just ordinary glass, and the warning is there so that you don't leave scratch marks.
It's also possible that the glass has an exposed hard-coat (pyrolitic) low-e coating -- some storm windows do, as well as a few types of double glazing -- but that approach would be unusual. Why not call up the manufacturer? (Or is the manufacturer in France? There are two meanings, after all, to the term "French doors.")
William,
There may be a film, but much more likely it's a caution the manufacturer added because of all the recent high-profile lawsuits around scratches by cleaning companies on large projects. One even made its way to the Canadian supreme court.
I don't know why window manufacturers don't switch to stickers that can be removed without scraping or solvents?
There is such a thing as interior side low E coating, but it is really designed for commercial buildings.
Yes, it would be nice if window stickers would come off easily and leave no residue. I peeled the specification stickers off our Marvin windows following the "don't use a razor blade" instructions. I cleaned the windows myself, and then I had a professional window cleaning firm clean them. I'll be darned, under the right light on a few of them you can still see where the energy code stickers were.
Some interesting numbers from a company that sells both triple glazed and low-e on the interior side:
http://www.cardinalcorp.com/products/coated-glass/loe-i89/
If it's in a door, it's tempered glass, and it's fairly easy to scratch. A lot of people just take a single-edge razor to glass and scrape off the stickers, very possibly leaving fine scratch marks from the fact that the razor has fine burrs in the edge. Some folks paint right onto the glass when painting the sash frames and then razor off the paint when dry, which also leaves scratches.
There might be a glass fabrication sticker on the glass that shows the thickness of the panes, the air space, the coatings, tempering, etc. Do you have these and what do they say?