Please look at the attached video. Does anyone have any idea what the heck has contaminated the windscreen? This causes the wipers to squeal insanely as it reaches the end of its travel; it’s driving me nuts. As you can see from the attached, I’ve tried removing whatever it is with a Brillo, Brillo and BKF and just BKF. Also I’ve used neat windscreen wash, ISO and acetone. So if this was the usual traffic or diesel film it’ll be gone, but nothing has touched it. 
All suggestions gratefully received.  
 

EDIT

Oh BTW; you need to have the sound up!

 

Edited 18 July, 20232 yr by numskull

Have you tried white spirit?

Or try gtechnique g4 nanoglass polishing compound ,used it in the past and it left my screen spotless ,i wouldnt use a brillo pad myself tho .

2 hours ago, Bap33 said:

Have you tried white spirit?

If IsoProp or Acetone won't shift it, I really can't see white spirit being more successful.

Edited 18 July, 20232 yr by Warrior193
grammar

I would try scraping gently with a razor or Stanley type blade perpendicular to the screen. If there is something there, it should come off. 

 

Machine polishing would be your best bet though. What age is the car and is it still the original screen?

Brave man using a bloody brillo pad on the windscreen!

 

I'd attack it with the razor method first.

My MK1 Octavia was vandalised by someone from the airbus factory throwing a pot of 2 pack resin across the bonnet which splashed up the screen, roof, side windows and door panels.

 

It was just about cured when I noticed, acetone removed some from the paintwork but most was too far gone and it was removing the OE paint so I let it harden for a week before mechanically removing what I could.

 

The screens were the easiest because as long as you dont use abrasive compounds they wont be damaged, a brillo pad is quite safe but is not doing the business for you.

 

I used a scraper that I have which takes a razor blade and is intended for removing carbonised deposits from ceramic hobs or paint from windows, that should cut through whatever schmoo you have on your screen perhaps followed with one of those aluminium swarf scouring pads.

 

The reason my car was vandalised is that someone had parked across my drive, their drivers window was cracked open slightly and I was carrying a full watering can when I saw the vehicle, it seemed like God or providence was guiding me! 😄

3 hours ago, Warrior193 said:

If IsoProp or Acetone won't shift it, I really can't see white spirit being more successful.

They don’t have the same chemical proporties. In addition Acetone and Isoprop are much more volatile than white spirit. They may evaporates before they could really act on the spot…

At least, I would give it a try.

Otherwise, maybe gasoline or diesel. Indeed the « greasy » aspect of diesel can dissolve spots sometimes…

Another efficient product that can be bought at any french drugstore,  is « eau écarlate ». Sorry I don’t have the translation. @J.R., can you help me please? I don’t know what could be an equivalent  product in UK. 🤔

 

Edited 19 July, 20232 yr by Bap33

Rarely had anything that didn’t come off after using quick detailer, a course clay bar and a glass scraper. 
Some tree sap sets like bloody concrete on glass. Definitely needed the glass scraper and a lube (glass cleaner, qd, snow foam etc)

9 hours ago, Bap33 said:

They don’t have the same chemical proporties. In addition Acetone and Isoprop are much more volatile than white spirit. They may evaporates before they could really act on the spot…

At least, I would give it a try.

Otherwise, maybe gasoline or diesel. Indeed the « greasy » aspect of diesel can dissolve spots sometimes…

Another efficient product that can be bought at any french drugstore,  is « eau écarlate ». Sorry I don’t have the translation. @J.R., can you help me please? I don’t know what could be an equivalent  product in UK. 🤔

 

I don't think there is a UK equivalent, I had not come across the product before but will buy some, it seems more suited to removing stains from textiles, Vanish stain remover might have a similar composition.

 

Whatever scmoo is on the screen WD40 used with the scouring pad would be more effective than soapy water, it softens many things like activated adhesives that solvents wont touch. I find brake cleaner to be particularly effective with some stubborn schmoo.

26 minutes ago, J.R. said:

it seems more suited to removing stains from textiles

It removes many stains indeed, but is also very efficient to remove anything that sticks: stickers, chewing-gum, rain, sap, tar... whatever the support is: textile, plastic, etc. and without damaging the support itself.

 

WD40 might be a good tip too for our friend @numskull

Blimey! Thank you @Bap33, @J.R., @UndertheRadar, @HeavyMetalRich, @Warrior193, @petrolcan, @Mickvrs220

So, yeah the car is a 2016 Superb and it’s the original screen. I’ve now tried White Spirit and that did nowt as did WD40, Panel-wipe (well what have I got to loose!) and QD too.
A Brillo is completely safe on glass @petrolcanas it’s far softer than the glass itself plus, of course, it has the soap which acts as lube. Since the video, I’ve also tried Astonish hob cleaner with a Brillo but that didn’t touch it either. 
But using the glass scraper sounds like a great idea @HeavyMetalRich so I’ll give that a whirl. It’s just so odd that whatever this is, you can’t feel it with a finger nail and it has built-up at that position on the glass at its end of travel, making the blade squeak like a banshee! @Mickvrs220 does the G4 need to be used with a DA? 
I’m thinking that cerium oxide will be the final weapon to attack this gunk. 
Thanks again for all your suggestions guys. 
Num

No it dont need to be used with a da but if all you have tried has not work mebbe the g4 wont work either ,go with the blade scraper see if that helps first ,save some money too👍

8 hours ago, Bap33 said:

It removes many stains indeed, but is also very efficient to remove anything that sticks: stickers, chewing-gum, resin, sap, tar... whatever the support is: textile, plastic, etc. and without damaging the support itself.

 

WD40 might be a good tip too for our friend @numskull

Sorry for mistyping…

So I’ve tried scraping the glass with a blade and nothing came off. Also tried some whizz-bang Japanese windscreen cleaner… which made the wipers judder like billyo so off that came - and changed the rubber blades and they still squeak in exactly the same way as the ones they replaced. I’ve bought some cerium oxide so I’m going to try that with a DA at the weekend. 

Here’s a little sound file so you can hear the grawnch on action!

 

Quote

Might be wrong, but isn’t that Coldplay? 😏

I’ll get me coat . . . . . .

 

Is the contamination visible at all?

The Brillo pad sound test was horrific.

I'm sure you're being careful, but it was a bit like watching someone juggling chainsaws. 😄

UPDATE TIME

 

So last week I decided to finally get this sorted once and for all.
I bought some cerium oxide (CO) and mixed it to a fairly thick consistency. Using the small lithium DA with a soft black flat pad, I set about cleaning the screen, concentrating on the contaminated area where the OS wiper ends on its sweep on both the vertical and horizontal, using up/down and left/right motion at a medium speed. After a dozen passes or so, the screen was completely smooth, with no sign of the contamination remaining. Incidentally, the screen remained completely cool during the process.
I then did the same for the NS wiper. Once all the contamination was removed, I gave the entire screen a clean with a thinner mix of CO.
The screen is now completely clean and the wipers are totally silent! 👍🏻 So I can thoroughly recommend CO to remove stubborn “stuff” on a windscreen. 

Nice work. A few products contain it - Carpro's CeriGlass is the one I know but there'll be others. You can either DA or hand polish using a Rayon applicator.

Cheers Lee👍🏻. That should be good for maintenance of the screen. Also, I need to use the CO on SWMBO Focus screen as it’s covered in wiper scratches, so I’ll get the rayon pad from Slims… 

A few other things I picked up recently:

Not all wire wool is the same. This LINK explains well with a chart after the first pic. Looks like Brillo is probably 0000.

Razor blades - Stainless Steel is fine, but Carbon Steel will damage the glass.