[cybersye]

quoted a job today, resturant, 4 large panes 8 x 5 ft
what I thought was dirt/ condensation on the inside was actually on the outside.
looks like dirty rain marks if that makes sense.
The guy there said they had tried everything to get rid of them, vinigar, white spirit etc.

I tested a small area with a wet scraper blade with no luck.
My conclusion is that its probably dust from the render of the flats above ( building is only about 10 years old) and its no doubt etched the glass.

Now I know I've probably answered my own question here but is there anything that can be done about it short of changing the glass?

although it was'nt the owner I spoke to the supervisor was impressed with my efforts and I said I would investigate further as to if anything could be done as I would like the contract.

thanks
Simon

[wezzy32]

do a serch m8 for water marks on glass.u may find youe answer

[ccmids]

are they double glazed?  some times i see a mark on the glass and when i look closer its between the glass , its like the window seals have gone condensation got in and dried out leaving a mark , if you know what i mean.

[Mike #1]

sometime's you do get staining from rendering i have come across this once or twice the spots have no edge in order to shift them with scraper i am sure this has been solved on here before might be wrong

[cybersye]

are they double glazed?  some times i see a mark on the glass and when i look closer its between the glass , its like the window seals have gone condensation got in and dried out leaving a mark , if you know what i mean.

unfortunately no they are single glazed units, there was a previous window cleaner, how long ago and whether trad or wfp I dont know.

[cybersye]

sometime's you do get staining from rendering i have come across this once or twice the spots have no edge in order to shift them with scraper i am sure this has been solved on here before might be wrong

yes they are just like this, almost as if they have been wfp'd with very hard water for weeks on end  although I doubt that this has been the case. from memory alot of the gf shops on this block were empty for a couple of years although how long they have been like this or the resturant been open, I have no idea.

[martin g]

I think by the sounds of it that it may be lime from the rendering above. It drips down and marks the glass. You cannot remove with a scraper as you know. There is a product called "lime scale Remover"?which I believe can be bought on internet especially for that problem.
Hope that helps

[cybersye]

thanks all, yes thinking about limescale remover now, but the size of these panes could become a day job, Ill try and get to speak to the manager and get a bit more info on how long the marks have been there and when there was last a window cleaner, maybe I could then buy something test a bit for a small charge and the price of the limescale cleaner before comitting myself.
Thanks for the help
Simon

[mistersqueegee]

If the staining is from silica (from the masonry of the walls above) it has bonded to the glass since glass is 72% silica. There are only 2 things to use to remove this kind of stain - a scratch removal system (it will grind of the silica) or a hydrofluoric acid like Crystal Clear 550 (it will dissolve the silica off the glass).

[Jack Wallace]

Interesting thread,
I have the same problem on a new job, It's a domestic house, the lady thought the last window cleaner caused the problem using wfp so was reluctant to let me have a go, (but changed her mind after I fluttered my eye lashes) 
I assumed it was just lime scale from his water (but did find it odd as only on the front of the house)
I have tried a shop bought lime scale remover (Mr Muscle) but it never touched it.
So I think I will order some Crystal Clear 550 and give that a go.

[williamx]

I have never used crystal clear so I cannot cment on it, but when I come across this problem I use T-cut which work perfectly.

[williamx]

Unlike t-cutting a car using it on glass is very easy.

[idealrob]

Pure water has no limescale or no hard water, trad water may, its a fact

30 years ago we used to clean roof lights, a bit like large velux windows in large comercial buildings with glass acid, it took the top surface off the glass and they looked brand new after. Don`t know if you can still get it or that its is legal.


idealrob

[wizard]

I us Doctor Power it a white round brick I bought mine at ASDA it come with a sponge but I used a pot scourers for soft materials its pink in colour it a big job will take a long time I would class it as a restoration job and should cost time most windies just leave it but can be good money and good for your business image to do work like this.