Hi everyone,

Today we took the car out in the evening, and everything was going fine but it eventually started to sprinkle. It was just a few drops here and there, so nothing to turn on the wipers about.

But after about 10 minutes, there began to form a type of fog or film on the windscreen. Thinking it was simply condensation on the inside, I turned on the defroster. A few minutes later, and it was only getting worse. So I jacked up the defroster. It did nothing. Minutes later and it got to the point where every passing car and streetlight was making it impossible to see.

So then we tried turning on the windshield wipers. Now, instead of the fog being limited to the lower portion of the windscreen, it was spread across the whole thing! Using wiper fluid helped momentarily, but made it too hard to see while driving. We had no choice but to pull over and try to figure it out. We turned the car off and it stayed. We opened the window and it stayed. Defrost ("demist") on and off, it stayed.

It formed at the bottom and seemed to be working its way up, so using the wipers just spread it even further. However, it also sort of... diluted it I guess you could say. So instead of being impossible to see out the bottom half of the windscreen, it was 50% possible to see out the whole windscreen.

The best solution was for me to get out of the car and just wipe it down with my hands. It got rid of it completely. But then once we took off again (to go back home at this point because we felt it was way to dangerous to do anything else), it began to form again. The only option was to leave the wipers on, even when the rain wasn't heavy at all or had stopped. It spread the fog (I think may be some type of film) at this point across the whole windscreen, rather than let it build up at the bottom and work its way up.

Does anyone know what this is? How can I stop it? I never want to see it again! It rains alot here and would pretty much render this car useless...

Once again, to reiterate:

Does not help:
Air conditioning
Demister/defroster
Opening the windows

Helps, but doesn't stop it, just spreads it evenly but lower density:
Wiper fluid spray
Using the wipers non-stop

Helps:
Wiping the outside of the windscreen just with my bare hands



Any and all tips appreciated!

Haven't seen it before, but have you used some sort of wash and wax to wash your car and used it on the windscreen?
Just an idea

no, we just bought the car. I have scoured the internet and theres millions of posts with the same problem and not yet one clear answer...

Were you driving through an industrial sector?

no, we were driving through mostly residential areas.

Give it a wipe down with metho.

I would say get a hold of some 3M cleaning clay and a razor blade. My guess would be a film of fallout. Glass feel rough at all?

I would say get a hold of some 3M cleaning clay and a razor blade. My guess would be a film of fallout. Glass feel rough at all?

Ill give it a check tomorow. What is metho?

methylated spirits lol

is that like alcohol?

If you want it to be lol But yeah it is a spirit, similar to paint thinners, turps etc

maybe the previous owner put the wrong stuff in the washer bottle? You could try emptying that and replacing it with the right stuff

Methylated spirits is alcohol with extra crap in it tpo make it poisonous to drink.
Could be a dirty windscreen
I've also heard that stuff like RainX works as long as its been recently applied, but then turns to crap and is near impossible to completely remove.

If it is crap on your windscreen, it will be on your wipers as well, change them too.
Get some winscreen washer soap stuff for your wiper water bottle and blast out any alge etc with the hose that might have formed in there.

So has the 'fog' gone now? Usually that happens when it's colder outside than inside. Usually if you use the windscreen washer, it will temporarily clear it up, but you need to keep the wipers on for a while until the temperature of the glass equalises inside and out.

Effectively you need a defogger for the glass outside, but you don't have one, so all you can do is squirt it with water, keep the wipers on and drive until it goes away. Usually 10-15 mins I find.

Yeah i would be giving the glass a good clean of metho and maybe putting some new wipers on why your there. If there is something on the screen its on the wipers too and all its doing it rubbing it back and forth on the screen.

Rain-X won't break down leaving a film. It does leave a slight cloudy film just after you apply it but this washes off. I've been using it for 15 years - fantastic stuff.

Also check the wiper blades. They might be smearing a film on the windscreen.

Reminds me of my first car, a 1982 Commodore with no interior fan. I once had to drive with my head out the window.

Most likely is that the windscreen was too cold.
Therefore the A/C demister setting on the front screen was just making it worse.
My son is a swimmer. Left house at 04:30 today.
Exactly the same problem.
He is learning to drive, immediately pushed the windscreen demist button and the problem got worse.
Wipers and washers temporarily cleared the screen.

So increased the internal temp to around 23 C, outside was 18 to 19C.
Screen was clear in a couple of minutes and stayed clear for the rest of the journey.
My reasoning is that the relative humidity was around 98 % in the area. I checked the BOM site.
Windscreen was cold, so the moist air immediately condensed on the cold screen.
Initially the problem was worse because the A/C was on the demist setting so the screen glass was much colder.

Go and check the relative humidity in your area at the time you experienced the problem. Example at Sydney Olympic park the RH was 50% at 5pm and had climbed to 80% by 10:30 pm.
Gerry

Thanks for the replies everyone. Like I said, it was sprinkling last night so I am sure that the humidity was high.

I suppose I can forgive the condensation that forms, it would be simple to wipe away with a windshield wiper. But it's the wipers that seem to just move the film across the screen. So I will do as suggested and give the windscreen a scrub and dry, and replace the wiper blades.

Thanks for the tips everyone, but can you also fill me in on where to find "metho"? At a bottle shop? or hardware store? or auto shop?

cheers

Methalated spirits is sold everywhere at stores like Coles, Woolworths, hardware stores. Its clear bottle mate, cant go wrong. Dont get confused with White Spirits, bottle looks identical to Methalated Spirits.

http://en.wikipedia.org/wiki/Denatured_alcohol

If it happens again, try using the air con with the heater on, I often put the a/c temp about halfway to hot and it clears it up well

yep, if your windscreen temp is lower than the ambient dew point it will fog up the outside of the car. you need to heat the windscreen when the outside of the windscreen is fogging up, you need to cool the windscreen when the inside of the car is fogging up.

i know this because my new cars climate control was doing this automatically, and i read the instruction manual to see why lol

yep, if your windscreen temp is lower than the ambient dew point it will fog up the outside of the car. you need to heat the windscreen when the outside of the windscreen is fogging up, you need to cool the windscreen when the inside of the car is fogging up.

i know this because my new cars climate control was doing this automatically, and i read the instruction manual to see why lol

is there any way of doing this without having to crank the heater up full throttle? It's hot enough outside (even if its raining) I don't want to have to turn on the heater in the car and make it worse!

And this condensation thing is really becoming a safety hazard for us... I think the film I was seeing when using the wipers was just the spreading of the condensation across the windscreen, need to solve this condensation issue first.

you could try the old trick of cutting a lemon in half and cleaning the srceen with it .plus new blade,s

the only way to heat the front windscreen is to use the heater. mums old 08 crv used to be terrible. sometimes you would need to be boiling inside the car to see out of it. rain-x worked, but it was a repeat every month job. give the windscreen a clean and rain-x and thats about as good as it gets. the film you are seeing is condensation, you cant stop it without changing the environment so that it cant be made (ie, using the heater or a/c)

is there any way of doing this without having to crank the heater up full throttle? It's hot enough outside (even if its raining) I don't want to have to turn on the heater in the car and make it worse!

Maybe try to just put the a/c temp up say to half way for a few mins just to clear it, then change the temp to cold and move the air flow to face or feet to stop the cold air directly hitting the windscreen.. always worked in all vehicles i've had. I found also sometimes if you have enough air flow around the car while air is directed at the face you may not need to direct a/c air to the windscreen to remove inside fogging.

So basically I have to use the heater and make sure its aimed at the windscreen to heat it so that condensation doesn't form on the outside? Cool air has no effect (except to make it worse) correct?

Is it possible to get hot air from the vents near the windscreen and cold air out the main vents to the face? My old car used to do this, no wonder I never had this problem.

Also, does using the demister help at all? Or does that cool the windows?

Thanks!

Have you cleaned the outside with any of the suggestions at all?

Clean the windscreen with metho, change wiper blades with some decent ones (none of that cheap crap), apply rain-x to the window and also buy the rain-x for the wiper water bottle, which will keep the film on much longer.

Also if you do get fog, I never use the heater. Takes too long. I use the aircon with the temp set to the middle (dont have the digital climate control) and have it come out at the windows. This defogs and also isn't too cold. Only takes about a minute to defog the glass.

Okay well today I cleaned the windscreen with metho. We will see how it holds up. The thing is getting fog/condensation on the outside every day now, regardless of humidity/if it is raining.

Any other suggestions? Hopefully the metho solution will help...

Why don't you ask a local - apparently the weather where you live is somewhat unique for this time of the year so it's pretty difficult for someone 'elsewhere' to comment on what appears to be a local problem. Years ago I lived at Oakey where in winter the windscreen froze solid almost every night - I was stumped and used to drive with my head out the window till it melted till a local said to just throw a rug or old newspapers over the windscreen the night before - problem solved and no more ice on the screen.
If you are getting condensation on the screen this means that the moisture from the (warmer) outside air is condensing on your (cooler) windscreen. This will continue till the temperatures equalise which may take 5 mins of driving. I'd try throwing a litre or so of warmish water over the windscreen just before you leave in the morning - this will raise the surface temperature of the glass above the outside air temperature making it impossible for condensation to form.

or he could just use the demister on heat setting....

or he could just use the demister on heat setting....

Unfortunately the heater takes about 5 minutes to start putting out useful heat, but if OP was prepared to warm car up before driving then would be OK.

Prop up your wiper blades, give the windscreen a good cleaning (brew up an awesome concoction of rainX + metho + windex + lemons + vinegar + urine (or maybe not the last one..)) and replace the blades with new ones. Just get brand new units, not refills. I replace mine regularly (had the car maybe 2.5 months, replaced the blades twice).