Expert: Robert Lamb - 7/3/2011

Question
I have a 25 year old home and some on the windows are streaked from what I was told could be screen oriented damaged.  Can vinyl screens cause damage to a glass window ?? When we have them wet, they look great but streak as soon as they dry.

Thank you.

Answer
Curt,

The simple answer is no. Vinyl screens don't cause damage to glass windows. But, metal screens do sometimes. In fact, we have encouraged our customers with old metal screens to replace them with non-metallic screening. Window cleaners refer to this damage as "screen burn." But you say you don't have metallic screens. Is it possible that there were metallic screens previously installed that caused the damage?

In any case, it seems that you now have damaged glass. By the way you describe the damage, it sounds like it possibly falls under the category of hard water damage.

There are basically two things you can do if minerals have attached themselves to the glass. The first option is to use mechanical action, basically buffing out the etching. The second is to use chemical action, let the chemical remove a fine layer of glass to reveal a new, smooth layer.

We have had a lot of success removing chemical etching using a product called Crystal Clear 550. The product is an acid based formula that includes hydrofluoric acid. The product must first be tested in an out of the way area. If it is going to work, it will work like magic. It's as simple as wiping it on and wiping it off. In rare cases it will cause an acid burn that will make the glass have a tin haze or grayish spot. Without getting too technical, tin haze has to do with the way float glass is made. The important thing when using this product is to test it as mentioned above.

If you opt for the mechanical method of removal, that too includes the use of compounds (chemical compounds) that will remove a fine layer of glass revealing a polished smooth glass.

Actually you can find all the supplies online at a window cleaning supply house like ABC Window Cleaning Supply or J. Racenstein.

Here's the chemical method link to one supply house: http://tinyurl.com/2br7hcy

Here's the mechanical removal method link: http://tinyurl.com/38kbx7s

You also might be able to find a window cleaning company that does glass restoration.

Let me know how it turns out!

Sincerely,

Robert Lamb

Window Masters
http://www.window-masters.com