[Andrew44]

Used a SL DT Mono and noticed that there were 4 scratch marks on the glass (6 to 8 inch long).  I assum e these were there before clean and only noticed them when I was looking closely at the finish.  However, can the brush scratch the glass?  I know grit can scratch the glass but can grit get lodged in the bristles and stay there ? 

Any views or experience of this

Cheers

[colin purewater]

plastic and nylon cant scratch glass
just cleck the jets arnt pocking out

[Andrew44]

I've check that and they are not.  I know the bristles alone can't scratch the glass, but can grit get lodged in them and scratch them?

[colin purewater]

may be mate not seen it myself
i thought only metal and diamonds scratch glass
but im no expert

[Andrew44]

Any other views on this?  Could grit be lodged in with the bristles or is that unheard of? Just want to be sure it was n't me scratcing the glass.

[richard jagger]

defo not

[Helen]

Even if you had grit lodged in the bristles, it would take some force to scratch the glass. The grit wouldn't be on the tip of a bristle and the bristles are not rigid enough to exert the force needed to scratch glass.

[Wc Solutions]

any brush can scratch the glass if it has any grit etc on the bristles...

[Andrew44]

I don't believe i did scratch the glass but was just a bit worries I could have.  I suspect the scratch was always there but became more obvious after the clean (dirt filled in the scratch) and because the windows were being looked at more closely.

Well that;s what I hope 

[dave carroll]

i think you're right.
  some years ago i had a customer complain that i'd scratched his glass above a conservatorywhich could only be reached from the side and not straight on if you get me. any way went back with a mirror set on a piece of wood and laid it on the ground, took the brush off the pole and scrubbed as hard as i could without smashing the mirror, guess what? one very clean unscratched mirror. during the visit he invited me in (ooh err missus) to see from the inside, when i put my hand out of the windowif you can imagine putting the frame in the crook of your elbow and moving your hand in an arc that was the EXACT form of the scratch, i suggested that prior to me cleaning the windows his wife had done them from inside which he agreed was true and that her ring had scratched the glass which he denied (obviously) because he couldn't see it before i cleaned it. so i believe that the dirt did hide the scratch and cleaning them made the scratch show up. he said he wanted to claim off my insurance so i gave him the details but never heard a thing.

   p.s he cleans his own windows now.

  Dave

[L.J.Thorpe]

any brush can scratch the glass if it has any grit etc on the bristles...

really

[L.J.Thorpe]

the brush stock can scratch if you grt grit on that and it makes direct contact with glass but bristles cant even if they have grit on them, as helen says bristles are not rigid enough

[markymark]

I read on one of these here forums that its possible the pure water has removed any residual dirt from pre-existing scratches, making them more obvious. Just a thought.... 

[Andrew44]

Thanks Dave

I really do think thats what the problem was and of course the customer will always look closer after the clean then before!  He didn't accuse me of doing it but I was just a little worried that I could have.

i think you're right.
  some years ago i had a customer complain that i'd scratched his glass above a conservatorywhich could only be reached from the side and not straight on if you get me. any way went back with a mirror set on a piece of wood and laid it on the ground, took the brush off the pole and scrubbed as hard as i could without smashing the mirror, guess what? one very clean unscratched mirror. during the visit he invited me in (ooh err missus) to see from the inside, when i put my hand out of the windowif you can imagine putting the frame in the crook of your elbow and moving your hand in an arc that was the EXACT form of the scratch, i suggested that prior to me cleaning the windows his wife had done them from inside which he agreed was true and that her ring had scratched the glass which he denied (obviously) because he couldn't see it before i cleaned it. so i believe that the dirt did hide the scratch and cleaning them made the scratch show up. he said he wanted to claim off my insurance so i gave him the details but never heard a thing.

   p.s he cleans his own windows now.

  Dave