Cannot clean render water streaks on glass

lansing

Hi,

I have an issue in trying to clean some windows that have water streaks with elements of a render residue from the rendered wall above.

When I clean the glass it appears to be perfectly clean but once it dries out, the render residue streaks come back again.

I have tried a glass scraper but these do not appear to be sitting on the surface of the glass. It resenbles a water mark that may be left on wall of a bath tub.

I have tried household window cleaners, vinegar, limescale removers and white spirits but nothing budges the water marks.

Could these be permanently etched into the glass? Is there anything that can be used to remove.

Any suggestions would be greatly appreciated.

Still stihl waters 3

Any Pictures, what type of render was used, synthetic, sand/cement, acrylic etc, if it was left too long it could really be stuck into it, if it's a synthetic silicone or acrylic based plaster you could try boiling water with vinegar to try soften it

lansing

https://www.boards.ie/discussion/comment/118367442#Comment_118367442

Thanks for reply. Will post a picture in the morning when it is brighter. It's K-Rend TC15 Acrylic render.

I have tried vinegar and hot soapy water but not a combination of boiling water and vinegar. Do I mix them half and half in bowl and bring to a boil?

Still stihl waters 3

https://www.boards.ie/discussion/comment/118367480#Comment_118367480

That's tough stuff, I presume a hp12 base coat which is also as tough, try the boiling hot water to try dissolve the acrylic in it

lansing

https://www.boards.ie/discussion/comment/118367681#Comment_118367681

Yes, hp12 base coat underneath. Will try the boiling water tomorrow. Should I add vinegar to the boiling water and if so in what quantity?

I did just try some Turtle Wax Glass Polish a few minutes ago. It did eventually take out a small portion of the streak where it wasn't particularly heavy. That's a relief to know it can be lifted somewhat. Perhaps a glass supplier would have a glass polish they could suggest.

lansing

Unfortunately the boiling water made no impression whatsoever. It's definitely etched in. I think a polish is the only hope. Was considering using baking soda in a paste. Could be a little more abrasive that the Glass Polish which has had some success in the lighter streaks.

Very wet today so couldn't get a good picture. Will post when it drys up.

Unreg for RI

Try a clay bar for removing tiny particles of dirt from paint. Google car valet clay bar

XsApollo

Was gonna post the same thing, try a clay bar.

corks finest

https://www.boards.ie/discussion/2058224140/cannot-clean-render-water-streaks-on-glass

Know u may think my suggestion is loopy but vinegar/ hot water with lemon in

wash it with newspaper’ dipped in this stuff ( definitely can clean windows etc which haven’t been touched foryears)

only a suggestion

lansing

Thanks to all for the suggestions. I'm currently waiting for a polish from a local glazing supply company that will hopefully take out the streaks. Attached is a picture of the problem.