Expert: Robert Lamb - 8/17/2007

Question
QUESTION: Robert,
My Ford truck windshield has this milky film all over it.  It looks like dried soap scum to me and acid rain residue to my husband.  We have tried many different products but nothing will cut it. Do you have any advice?

ANSWER: Barb,

Exactly what have you tried?

Robert Lamb
Window Masters
www.robwcleaningservice.com

---------- FOLLOW-UP ----------

QUESTION: coca cola, steam cleaner, orange blast, various window cleaners, vinegar (although suggested, hesitated to try wD 40)

Answer
There are basically two methods used to restore damaged glass of this type.

One is chemical action. The other is mechanical action. You have tried some chemicals. The acid based ones, by the way, are better than alkali based ones (vinegar; orange products; even Coca Cola is an acid). There are of course stronger acids that you could use but with extreme caution for your own safety, the safety of your paint job, and even the glass.

My suggestion is to try mechanical action. The mildest mechanical action first is best. Steel wool is often used to buff out glass in the window cleaning profession. Steel wool is graded with zeros. Four zeros being one of the finest grades on the market going down to one zero which is too abrasive and probably will scratch the glass. I have often used the triple zero (000) grade steel and never had a problem with is. You may think a plastic scrubby pad will be less abrasive, but you may actually scratch the glass if you use the wrong grade. Yes, 3M (and most other companies), use a grading system where color, not zeros is used to identify how abrasive a product is. The least abrasive color is white. If you want to use a plastic scrubbie, only use a white pad, anything else probably will scratch the glass.

Again, my suggestion is to use large circular motions on the glass with triple zero steel wool. You can either do this alone or in combination with (acid based) chemicals.

There are other chemicals and abrasives that you can use to buff out your stains. One good place to look is in a window cleaning supply house. There are several of them on the Internet (J. Racenstein, ABC Window Cleaning Supply, Colker Company, Detroit Sponge, etc.).

Just read and follow the directions carefully.

Sincerely,

Robert Lamb
Window Masters
www.robscleaningservice.com