Car windscreen. (Windshield)

Morning Bangorjohn, I get the same effect! But this only happens when the screen is dirty inside! After I clean it, the problem goes away. If you clean the glass with a good cleaner that doesn't leave a residue on the glass, the problem tends to go away! The problem occurs (for me) when you wipe the glass with your hand or an old rag to see! this tends to make it worse the next time! The other option is to drive with your head out of the window! Maybe not a good idea in Wales but it works fine for me!

Happy new year John

The polarization of glass can create an odd visual effect when viewed from other than
90 deg. The effect can become very odd indeed if one is wearing polarized lenses while looking through the glass.

I have only experienced this when viewing glass other than the front windshield, accept for the very top portion. Office buildings can also produce the effect.

Don't know if this is what you are experiencing or not.

cr3

I have the same problem with my VW Jetta, if there is any moisture on the outside, or if there is any fog on the inside it is especially bad, to the point that I have to stop the car...

I'd go along with John (Mr.T.B.) - giving the glass a dam' good clean (inside & out) can make a huge difference to visibility - especially when driving into low-angle sunlight.

I've had some funny effects from polarization, but never enough to unsight me to a dangerous extent. Effects will be exacerbated by use of polarizing shades, but if you're not using them, that can be eliminated.

Clean!

It is actually quite astonishing to see exactly how dirty the inside of your windscreen becomes. It is caused by the exhaust gas from other cars around you and every time you de mist your windscreen the particles coat the glass surface after they get dissolved in the condensation on the windscreen.

Good clean is probably all you need. Also note that it is almost invisible when the light does not shine directly on your screen, that explains why it goes in the shade.

If it is still there you should check if your windscreen is laminated and if it is possible that the layers have come slightly undone or are in the process of coming undone. This is never over the whole screen though as it starts normally at one side or corner.

A clean screen is a happy screen!

Get into the habit of not touching the screen with your hands or a rag. Do you clean your glasses with the palm of your hand....I hope not!! The dirtier the glass, the easier it is to get misted up, and the harder it is for the de-misters to de-mist! If you must wipe the glass, use a good quality moist chamois leather.

Start with a good cleaning on both sides of the glass. A vinegar/alcohol/distilled water solution works pretty well (if not best). Use a clean lint free cloth. It may take two or three applications to clear it off.

I find that vapors from the vinyl on the dash or even the dash/plastic cleaners will condense on the inside of the windscreen. I would suspect that some form of Armor All dash cleaner was used by the dealer to make the dash shine and the oils and solutes tend to coat the inside glass after being in the sun. Was the dash very nice and shiny when you bought it?

I used to have this problem with the windscreen in a 1964 MGB, but never went into an analysis of the cause. I'll just sit back and listen (er, read).

one drop of milk in water scatters light. Any small particulate matter on the inner our outer surface will cause this. In addition, fine dust scratches and surface etching also do the same thing.

clean and wipe dry with a squeegee in and out. if the glass is dust pitted or otherwise etched, you need a filling polish to reduce or remove the problem, if you can find that stuff/

It probably is just dirt. 70% isopropanol (rubbing alcohol) on high-quality paper towels and a bit of elbow grease inside and out work wonders. Don't forget to clean the wiper blades. This also greatly reduces glare at night. Avoiding a collision (or even a close call) will more than repay your diligence.

I did have to replace one windshield after driving through a sandstorm in the California desert, which left tiny scratches that were invisible in the daytime but played havoc at night. Your vehicle probably hasn't encountered any sandstorms, unless it had lived in North Africa in an earlier life.

Yes it's almost surely the inside of your glass needs a proper streak-free cleaning.

I'm surprised that no one has mentioned one of the most foul of inside windshield contaminants. If any of you smoke while driving, particularly if the windows are rolled up ... I think you'll know what I mean. The amount of yellow tar that will build up on the inside can be quite incredible. Ghastly, even. It can seem relatively invisible ... until you take a clean white cloth to it. And that will certainly cause the glare you speak of; among all the other causes that have been suggested.

As far as the outside of the glass ... I suspect the most likely culprit is micro pitting .. or sand blasting. Not very noticeable until the sun hits at the right angle. And then you can be driving blind in an instant. This will happen most often if you frequently drive on particular types of dusty roads.

I've experienced both these situations. Those are my guesses.

Hazing can be a problem. It actually causes a lot of accidents. The outside of the windshield gets constantly abraded by small particles and acid rain can also contribute. When the light strikes this abraded surface it diffuses and lights up the surface thereby occluding your view.

Try using the product "Rainoff". I don't know exactly what it does, possibly a fine wax but it seems to help with the problem, for a while. You have to keep using it. Plus it is hilarious the first time you see the rain shoot off the window. The only other and the best, though expensive, solution is to have the windshield replaced.

I have a 94 T-bird that is notorious for seeing visible prisms, streaks, etc. In my case I know it's not a matter of cleaning since I've tried various specialty glass cleaners, both inside and out.

I suspect the problem may be due to differences in the refraction index of the interior laminate and the glass on each side of it. Some windshields may be at the upper limit for manufacturing error and this limit may vary from one manufacturer to another.

I ran across this item that may provide some additional insights:

Reflection in the windshield:

Dashboard reflection

It is best if the dashboard has a non-reflecting dark colored surface.^[3]

A small dashboard gives some reflection on the lower part of the windshield.

A big dashboard can give reflection on eye height.

A-pillar reflection

It is best if the inside of the A-pillar has a non-reflecting dark colored surface.^[4]

If the side of the window is curved there is less A-pillar reflection. ^[5]

Light through roof reflection

Some new model cars have a very big roof-window. Sometimes the sunlight through the roof lights up the dashboard and gives a reflection in the windshield.

-John

There is one thing no one mentioned. Auto-glass is actually 2 panes of glass glued together. If the seal leaks, even microscopically, then the glass would separate. When viewd at 90 degrees it may not be noticable but, when the sun is at a certain angle, the two panes of glass would cause a refraction pattern.

Try a good cleaning. If that doesn't work take it to a good auto-glass place and ask them. If they start by cleaning the glass then you know you are not being ripped off.

I don't know if I'm right but that's my 2 cents. Hope it helps.

Orpheuse

Thank you. For a minute I thought my face was going to explode!!!

Happy New Year to you all. I agree that this problem is a real nuisance. Is the glass toughened or laminated - all UK cars have each screen marked in the corner with approval and date codes? Toughened often creates diamond effects, but laminated should not. Does the car - Fords often do - have an electrically heated front screen with fine wires in?

If it is not a glass defect it is more than likely to be dirt inside the screen

Even if the driver never touches the screen, and does not smoke, and the pollen filters in the ventilation system are fresh, there is still the internal emission of the plasticsisers in the car interior. Having worked with GM for many years we were always aware that a new car gives of many chemicals - particularly in hot weather, which condense inside the glass. This continues for 20 or more years, which is why the plastic trim becomes more brittle with age.

I used to have an employee who was so focussed on glass cleanliness that she would clean the inside and outside of every windscreen at least once a week. Her technique was a good a domestic glass cleaning spray and a large supply of newspaper to rub the screen - do not use the same piece of paper twice - then repeat with a clean piece of workshop tissue.

Good luck

I recently purchased a top model 3 year old Honda privately, and in order to get a road worthy certificate the windshield was more stringently inspected than normally at a service.

There was one 1mm sq stone chip just above the steering wheel which caused the inspector to reject the windscreen outright, and I had to get a new one. In the process of discussing the waste of an otherwise good windscreen for such a trivial chip, he pointed out that the windcreen also had microscopic sand blasted pits all over. Thes were not visible ordinarily but looked like myriads of bright stars when viewed travelling into the sun just before sunset.

He further explained that the glass used in modern cars is very much softer than it used to be, and in travelling from Melbourne to Adelaide and back several times (which the previous owner had done) one passes through several hunderd miles of dry sandy farm land which is often made airbourne by the wind.

The moral of the story is to inspect the windscreen of a car you intend to buy very carefully for sand balsted pits. They really are a nuisance when travelling into the sun.

Thank you for your reply, your experience seems to be nearest to my problem that I have had from almost 15 people! I want to to thank everyone for sharing their thoughts with me, As far as I know this vehicle was never driven over any deserts! but strangely enough the previous owner does live in a small seaside town, I think my next move will be to ask him just how near! because they do have westerly gales along that coast!

The other point you mentioned was the 1mm chip that caused you to have the screen changed, in this country, that sort of damage can be repaired by the use of plastics I believe, without having to resort to changing the whole screen, but then if you were having my symptoms, you were probably better off!

At this point I would like to thank everyone for their time and trouble answering my letter, trivial as it may seem, as regards the cleaning, I gave it a good wash with a great additive obtainable from Lidl's, and finished with a leather, then applied AutoGlym, and polished off, I am now waiting for the sun to shine!

Thanks again everyone. PS. If anyone is interested my car is a Skoda 1.9TDI Octavia, it regularly returns 68/72MPG on a run!

I get this hazing almost every day as the main road through the village where I live seems to have been positioned to point directly at the setting sun. Cleaning the screen inside & out helps but I've tried many cleaners & they often make this particular problem worse by leaving streaks that are not visible in normal circumstances. The best cleaner I've found so far is Auto Glym glass cleaner.

Try Rain-X. I had erroneously indicated it was Rain Off in a prior post. It isn't a cleaner exactly but if you apply it as directed, your window will be very clean but also less hazed.

One thing not mentioned here is the possibility that you have a minor leak in the heater/defroster core allowing steam and ethylene glycol vapors to deposit on the inside of the windscreen. If you smell anti-freeze even a little bit you could have a leak. Fixes the visual problem and a potentially dangerous situation when the heater core finally ruptures.

Thanks again for all your comments, believe it or not we actually had some sun today, I was able to put all my cleaning efforts to the test, Do you know nothing changed! What I was able to see, was a myriad of tiny marks within the glass, just as if someone had been firing minute missiles at it, exaggerated of course, but you can see these imperfections in the glass, which causes the glass to become slightly opaque, I noticed especially the roadside wall was merging with the road, then as I got into the shade again, it became quite clear, I spoke to the previous owner, who stated he had always kept the car in the garage, whenever it was not used, and always parked with the back of the car to the prevailing winds, so no chance of any stray sand blasting it. So it's the end of the road folks, it will go in to have it changed, thanks again for your deliberations, as the man said"Mystery creates wonder, & wonder is the basis of man's desire to understand" It has set me thinking, `I wonder how I got myself in to this mess`in the first place!

Hey thanks for the feedback and updates. It happens all to often that the original poster just drifts off into oblivion like a car with a faulty windshield(?)

Much luck to you.

Hi thanks Rummel, I'm now waiting word from Skoda themselves, but they seem to be driving with the brakes on!

I have now had an answer from Skoda, which is really just a copy of what the dealer has told them, to the effect that he wants a written report from the windscreen specialist as to the nature of the defect, I have already told him the reaction of the `specialist`"claim it on your car insurance!" He also goes on at great length to say that the conditon was never brought up by the previous owner, likewise not from any other potential owners who test drove the car before me, Who would be able to replicate what I have found from a few minutes down the road on a test drive? I certainly did not on two test drives I did before deciding to purchase, it was only when driving in the low lying sun rays a fortnight later that I stumbled on it. I have now had advice from my longstanding friend in the car trade, who showed me how to shine a bright LED inspection light at an angle to the screen, you can see the screen is covered in tiny white marks which are within the glass, when these are viewed thro' a magnifying glass they are seen as tiny whitish dots or bubbles, I also thoroughly cleaned the glass with AutoGlym glass cleaner again today, seeing as the sun was shining! and the screen has a dust like appearance all over the outside, when in the shade again, the condition disappears! Does anyone in the UK know how I would stand, if I was to take advice from a Trading Standards Officer?

Don't know how you'd stand - but it's worth asking - it's free!

I once took a kids (my daughters) plastic ruler, which had snapped & shattered into hundreds of tiny sharp shards (when she overstressed it as kids do), to Trading Standards. I didn't get very far, but they followed it up and checked all the specs on what could & couldn't be sold to kids, and I got a full reply. As the law stood at the time, there was nothing that could be done.

Anyway, as I say, it's free, so give it a go. Good luck,

John

If (as I understand) the cleaning did not help, it is damage that can only be repaired with a new windscreen. Why companies cannot polish it away I do not know, its probably not financially a good idea, screens are cheap.

I find that after 2 to 3 years on any car, during the last 20 years or so, always the same problem. I am sure that windy/sandy conditions will make it worse even quicker......

Have you got good glass insurance?........then chuck a rock!!! Or drive closely behind heavy trucks with ballast loaded!!!

It happened to me and the car 6 car lengths ahead of me, which stopped dead in the middle of a 4 lane highway. I was slowing when I saw his brake lights glowing red through the glare. Bam!! Totalled my car and messed up his back end. The inside of the windscreen had a dirty film on it. Since then I have made sure it is clean inside and out.

Thanks for your mesage Traganan, the inside of my screen is surgical clean! I have always made a point of cleaning both inside and out ever since I started driving way back in 1950, In this instance it's the worst screen I have ever had the misfortune to inherit, I have taken the car to a windscreen `specialist` I have also spoken to one over the phone, both have put it down to stone chips, I have agreed that I do have some of those, but they do not obscure your view like this screen does, The chap who saw it said it looks as if the other owner has been driving behind a road gritter! but if you give the screen the finger nail treatment, as you would do if you were checking a surface finish on metal, you can not feel any stone chips, except in the obvious places, also when a strong light, such as an LED inspection light is shone at an angle to the screen, then the myriad of tiny white marks can be seen within the glass, the specialists say otherwise, but I think I have a fair idea of what I am looking at, I haven't been in engineering all my life without picking some tips up!

To give you the latest news re; my probematic windscreen, I got in touch with my Insurance Company, and explained my problem, the answer came back, `no way would they entertain paying for the cost of replacing the screen, because the problem was there when I bought the vehicle`, having spoken to the proposed installer, I went on to ask him the cost of having the work done if I paid, I also asked what was the cause, his reply was the plastic interlayer was damaged in some way probably by contact with air, this must be installed under vacuum during manufacture? The end result was I went back to my dealer with the good news! and he has now agreed to replace the screen, I'm not sure if, or how much I have to contribute, my argument is that as I inherited the problem from him, he in turn may have inherited from his supplier, they or him should be responsible! I was asked also why I did not cause an accidental breakage with a spanner, then I remembered the qotation, `the man who lends the tools is out` these things tend to come back and haunt you I always think. Just thought I would put a cap on our discussion.

Well done with that. However the problem with our BMW windscreen at 160,000 miles was that the outside face of the screen was pitted, ie eroded by the action of the dirt hitting it over the years. As the car was becoming too expensive to run and was badly damaged underneath when it was impounded by the agents of the DVLA having just passed its MOT (but that's a long and tedious story which ended with the impounders paying up and the car being off the road for months) it was sent away to motoring heaven. The pits in the screen would refract the low sunlight as you describe and so was also a hazard.