[Purecleanplus]

I'm WFP and mostly have customers amazed at the results. However I've a few who since their windows are cleaner than ever have noticed mineral stains on the windows and have wondered if that was down to me.
To be fair, they've all listened and accepted that it is the rain water running down their stonework or more often pebble dashing and depositing leached minerals on their windows over a period of months and years. (I used to be a civil engineer you know!!) Just like stalactites and stalagmites.
It's worse where the rainwater drips from the ledge above onto the window sill below.
Anyhoo, I've tried scrubbing and even (carefully) scraping the stains without success. Anyone know of any solvents etc that'll shift it?
 

[Nathanael Jones]

something like this should do the trick:
http://cgi.ebay.ie/Bruces-GSR-Window-Water-Spot-and-Stain-Remover_W0QQitemZ290025693353QQihZ019QQcategoryZ20606QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Sorbo do a hard water stain remover,... but I can't remember who sells it in the uK.

[Purecleanplus]

Awesome, it looks worth a try.
Anything for a few brownie points.
Cheers

[Davew]

Or this
http://www.windowcleancentre.co.uk/productdetails.aspx?ProductID=186&SectionID=26

[Londoner]

Before you try that buy some Cillit Bang for limescale. It works a treat. Also buy some of those little yellow sponge pan scourers with the green stuff on one side. Spray on the window and scrub it in with the scourer then rinse with pure water.

Windows often get "wash down" from the brickwork above. Other problems include sprinklers in the summer or washing cars with a pressure washer ( the spray can drift a long way ) Also watering hanging baskets with a hose can cause marks.

Sometimes a window just looks "tired" and a good scrub brings it up.

[tonyoliver]

pour the cilit bang in a sprayer tel em its special and charge a tenner to do it

[Purecleanplus]

Thanks guys. It does bug me when a window isn't as clear as I like to leave them.

[Londoner]

Try this some time. Nothing necessarily to do with limescale. Pick an oldish window ie five years old or more. Preferably with a few paint spots on it.
Give it a good soaking with soapy water from your applicator then with a new blade in your scraper "shave" the whole window.
You can feel and hear all the bits as they come off. Its often quite amazing what a build up you get on glass.
Also, trad cleaning in a hard water area, depending on how its done of course, will cause a microscopically thin layer of hard water to be left on the glass each time. The water evaporates almost instantly but the limescale builds up over time.
I clean several houses where the windows are over a hundred years old and the buildup can be seen quite clearly in the corners. I don't treat them because they are leaded and so fragile that they move visibly when I clean them. Really scarey at first but I am getting a bit more used to them now.

[Spursboy1972]

I use MDR it is not harmful and you can just rinse away with wfp or mop it up with squeegee.

Use it with a white pad though.