[A/S] glass cleaning with jewellers' rouge

["nickcrowhurst" <NickandSandra@xxxxxxxxxxx>]

It's very difficult to clean some smears off windows. If none of the 
usual treatments work, you may have silicon smears from silicon used 
on the window rubbers to prevent them sticking. I had this on my 
Excella windows, and nothing would shift it. I also had some vague 
imprints left from some commercial transfers removed from my truck 
windshield. One day, here in England, my wife, Sandra, sidled up to a 
car windscreen repairer working in the street, fluttered her 
eyelashes at him, and asked how to get rid of the smears. He gave her 
a tiny pot of a reddish brown powder, which is, I believe, Jewellers' 
Rouge, the powder that jewellers use for polishing precious 
materials. It worked like magic on the smears. In the past it was 
used as a final polish by glassmakers. For those interested, it is a 
mixture of ferrous sulphate, ammonium hydroxide and ammonium water. 
This mixture is then filtered, and burnt in air. The residue is 
finely powdered, and this is jewellers rouge. You can buy cloths 
impregnated with it. A search on Google will show you where to buy 
the stuff, or try your local small jeweller's. If that fails, your 
local windshield fitter may have some. It's magic! Now would the guy 
have given me the powder? Nick.