strange glass scratchs

[Gazman16]

Hi all

I just got a call back on a job that I fitted a few years ago about marks on the glass.

I have taken a photo (was a bit tricky to get them to show up) You can just about see several small marks. There are hundreds of small chips in the glass about 2mm in size.
The customer agrees that they werent there when I fitted them (hes a fussy one so he would have spotted them much sooner) and is happy to pay for replacments but we are puzzled about the cause.

Its a quite out of the way area so its unlikely to be by thrown stones.
He doesn't jetwash his path so it shouldn't be anything flicking up.

Anyone got any ideas as to the cause? View media item 45016 View media item 45017

 

[crank39]

Anybody been doing some grinding or stone cutting with their backs to the window? Thats the first thing i'd suspect

 

[Gazman16]

Anybody been doing some grinding or stone cutting with their backs to the window? Thats the first thing i'd suspect

Good thought. There was some building work next door a year or so ago but there is a fairly high wall between the houses that would have sheilded most of the window.

Any other ideas?

 

[foxhole]

Clothes line close by, anything hanging with a metal rivet [jeans] or buckle might repeatedly tap or rub against the window scratching it.[Or even loose end of the clothes line]

 

[misterhelpful]

Birds, especially robins, will attack their reflections trying to protect their territory but I don't know if they are capable of chipping the glass and would imagine the homeowner would have heard or seen it, if this was happening.

 

[Gazman16]

Clothes line close by, anything hanging with a metal rivet [jeans] or buckle might repeatedly tap or rub against the window scratching it.[Or even loose end of the clothes line]

The washing line is fairly close. I will have to ask him if its a posibility

 

[Gazman16]

Birds, especially robins, will attack their reflections trying to protect their territory but I don't know if they are capable of chipping the glass and would imagine the homeowner would have heard or seen it, if this was happening.

I have seaguls that keep attacking one of my windows so I had thought of this but the scratchs are quite unevenly spread out everywhere on the glass, There would be no where for them to purch to peck at the higher areas.

 

[crank39]

Are there any marks on the pvc or are they just on the glass?

 

[Gazman16]

Are there any marks on the pvc or are they just on the glass?

Only on the glass

 

[misterhelpful]

There would be no where for them to purch to peck at the higher areas.

Some of them are nutters and do it on the wing!

http://www.youtube.com/watch?v=5IVMywTKWVI&feature=related

But as I said, probably would have been noticed.

 

[JohnD]

It couldn't be sparks from fireworks, I suppose?

but that would be on the frame/sill as well.

 

[masona]

Anybody been doing some grinding or stone cutting with their backs to the window? Thats the first thing i'd suspect

I have seen this before with the grinder or welder and yet it's damaged the glass and not the upvc! If you can take a close up photo or can you see the spot is pitted, if it's a fine metal debris, they tend to rust into the glass and the only way is to replace the glass. It's the same with showers glass door, if you don't wipe it clean after each shower then the glass will be pitted because of the reaction of the soap and water, it's usually 1/3 of the bottom of the door, always best to hose it down then use a squeegee rubber, once the glass is pitted nothing will clean it