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Old 11th September 2008, 11:23   #106
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Originally Posted by dreamdiesel View Post
Hi All, I just discovered this thread and was taken aback about other experiencing similar issues.
Recently had been to Udupi in my Swift VDI and started raining. I switched on the AC to windshield mode with non-recirculating air (fresh air). the temperature was set to minimum. Though it was a slight drizzle, the windscreen started fogging from the outside. I try to maintain the outside and the inside temperature almost equal. The conditions outside was pretty humid with slight drizzle. The fogging started from the lower center of the windscreen and slowly started to move up till the halfway mark (almost triangle shaped). "It was not the typical fogging effect, but more like crystalline frost marks following the wipe pattern (here's the difference: You can't write on it with your finger unlike the regular fog on glass. It remains like a stain)." I had recently got the blades for the wipers replaced. Driving in the night on the NH was a nightmare at that point of time with the opposite traffic with blasting high beams. I though the fogging was due to dust/oil sticking to the windscreen. I stopped and washed the wiper blade and windscreen with face wash which was in the car. Started driving and fogging started. This happened even after I had the driver side glass lowered a little.... Finnaly reached the destination, but had to be really careful and the experience was quite scary... A similar incident occured almost a year back when I was passing through Jog Falls Ghat section (caused a minor accident (dent on driver side door) with a tempo trax from the opposite direction) and it was a similar kind of rain..

Please help....Any thoughts on this??
Hi,

I face the same problem even after using Aero-twin wiper blades from Bosch...
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Old 11th September 2008, 11:50   #107
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Hi All,

I use the following methods and dont have any issues with fogging:

1. To clean glass , I have Vista Glass Cleaner and have it mixed with water in the windshield water reservoir. This can be used when the wiper be it good or old leaves streaks in heavy rain or light drizzle to clear the windshield.

2. When fog forms from outside, switch AC on , even it 1 setting it takes seconds to clear the fog ( I dont use in re-circulation mode)

3. I tried an experiement, Heater with all windows closed increases the fogginess, instead heater with windows slightly open at the top reduces it . ( No idea why.. but these were the results)

All this clears the windshield , sometimes there is a tiny patch formed on the lower part of windshield which remains.. that is not a concern , but not been able to address that issue yet.
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Old 14th September 2008, 11:39   #108
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Hi all, I just posted the problem faced by me in the other thread, and then came across this one. But here, I notice that u guys are speaking about a different issue, condensation. In that, I feel condensation occurs on any surface which is cooler than the air around it. (This happens because the ability of air to hold moisture is proportional to temperature. Hence warmer air can - and usually will - hold more moisture, but when this air cools down it lets go of the excess moisture which it can no longer hold.) So in the rain, the windscreen usually cools down with the rain water falling on it. The air inside the car (with windows up) will be warmer due to body heat and exhalation of the occupants. When this warm air (inside) meets cold windshield, condensation forms (again on the inside).

On the other hand if you have an AC running inside, this cools up the air inside and thereby clears the problem initially. However after some time a new problem arises. The cold air inside cools down the windshield to temperatures less than the outside air, and now when the warmer air outside meets cold windshield, you will have condensation forming outside. This is usually aggravated by an AC vent blowing directly on to the windshield, which cools down the glass pretty quickly and you have the problem appearing immediately. This is the reason for the triangular shaped condensation described by our friend below simple an effect of the air blow and the temperature conduction across the screen.
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Old 15th September 2008, 09:34   #109
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I observed this problem carefully when faced last time, and it seems there is a solution to minimize it's effect if not to eliminate it completely Basically, it is the extension of what I have been telling. Repeating here once again-

1. For internal fogging, the solution is to use A/C and/or heater. A/C is much more effective here due to de-humidification.

2. For external fogging, A/C can't be used so heating the glass by blowing hot air is the only solution. Defroster is also very useful, but I have never seen cars with defrosters on front wind shield or window panes It is provided for rear wind shield only (if at all).

However, A/C has adverse affect on external fogging as it cools down the temperature of glass. So, one has to usually use A/C and heater simultaneously, and that is the way to go. (I am presuming that opening up windows is dismissed because nobody would want rain water to enter into cabin.)

Coming back to fogging due to wiper- I think sticky/gummy deposits are ruled out because 1. It would not automatically vanish 2. It should clear up upon washing the glass and wiper blades properly. But both these points do not hold true. Therefore, it seems like wiper (for whatever reason) leaves behind a thin layer of water, and it gets eventually evaporated automatically. Wiper blades act like brush strokes "painting" the glass with water. To me it looked like temperature of glass was warm enough to not allow condensation on outside, but it was not warm enough to quickly evaporate this thin layer of water. So, I just tried to blow even hotter air onto windshield raising the glass temperature further, and it did make evaporation much faster. However, I had to bear with uncomfortably hot air. This can be minimized by directing all air onto glass, and once the glass heats up, reduce the temperature little bit. This hot blow can be repeated as and when required. So, a partial solution at least! I don't subscribe to the idea of balancing inside/outside temp as it makes no sense to me. You should just keep raising the temperature until problem is solved, that's it.

I have no idea of the physics behind the layer formation. Was thinking of replacing blades, but based on experiences here I don't think it guarantees anything. (Same problem even with bosch aerotwins!!). Other possibilities that come to my mind are 1. Can it be due to reduced force with which wiper arms press blades against glass surface? I know they are spring loaded, which might loosen over time. 2. Trying out rain/water repellent soulutions. This may be fine if it has long lasting effect. But if it has be be applied every now and then (that too when raining) then it would be a pain, I guess.
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Old 15th September 2008, 10:41   #110
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I had sprayed glass cleaning solution on the windshield when I faced the milky mist problem. The glass becomes clear for sometime and then the mist forms again.

I have also noticed of late that the windscreen does not clean as nicely as before. I suspect there is a thin film of residue on the windshield which the wiper is unable to clean properly leading to the milky mist.
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Old 16th September 2008, 21:16   #111
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Sonax glass cleaner and Sonax windscreen wash fluid works for me.
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Old 16th September 2008, 21:22   #112
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Does it have to do with the quality of glass used in windshields? I mean is this a problem only with the middle segment sedans? Maybe this does not happen with the imported Audis and BMWs
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Old 16th September 2008, 22:01   #113
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Quote:
Originally Posted by dreamdiesel View Post
"It was not the typical fogging effect, but more like crystalline frost marks following the wipe pattern (here's the difference: You can't write on it with your finger unlike the regular fog on glass. It remains like a stain)."
The nightmare happened again this time.. Was coming back to Bangalore from Chikmagalur over the weekend and after Kunigal started raining. Was around 9 in the night and on a 2 lane highway.

I switched on the AC and directed it towards the windscreen. The foggy effect inside the windscreen got evaporated and the visiblity was clear with the wipers running at 2-3 speed. Then the fogging started from the outside and I switched from cold air to normal temperature (Slightly below halfway between cold and hot). The visibilty slightly improved but still had the fogging effect from outside.

I noticed something different this time. I switched on the windscreen washer. The place on the windscreen where the water hits became completely clear. I guess because of the warm water hitting the windscreen cleared it. Because of the difficulty I literally stopped on the highway and had to stop on the side of the highway for some time till the rains became tolerable.

I usually use clean plain water for the windscreen washer. I will try to add Sonax washer fluid and see the results
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Old 17th September 2008, 10:00   #114
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Originally Posted by dreamdiesel View Post
had to stop on the side of the highway for some time till the rains became tolerable.
Quite appreciate that. More people should do the same if they have trouble in visibility as it can cause major accidents self and to others.
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Old 17th September 2008, 10:53   #115
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During mid of August I drove to Chikmagalur. It was raining heavily Hassan onwards and I had to drive along wipers ON. After sometime I noticed, this problem was NOT there !! (milky layer).
> It was raining enough, so I did not use windshield washer
> I had not changed the blades/rubber liner. No special treatments except cleaning with a damp tissue paper (which i do normally)
> I did not change the way I use A/c. (Switc the A/c ON only to 'prevent' fogging from inside.
> Problem was partial when it was just drizzling and highway had traffic with dirt in the air.

So, is it something to do with polution in our cities? as suggested by one of our friends in this thread?
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Old 17th September 2008, 19:37   #116
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Shyam, what was the temperature? I mean was it too cold or not much. Sometimes it is not so cold even while raining, and I guess the problem may not be noticeable in that is case. I think it gets aggravated under very cold atmosphere (as explained in my last post).
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Old 18th September 2008, 10:45   #117
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Quote:
Originally Posted by santosh.s View Post
Shyam, what was the temperature? I mean was it too cold or not much. Sometimes it is not so cold even while raining, and I guess the problem may not be noticeable in that is case. I think it gets aggravated under very cold atmosphere (as explained in my last post).
Yeah, it was not VERY cold.
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Old 29th September 2008, 23:46   #118
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Default Problems Problems... !!

OK. I have the similar problem with my Swift Vdi from day ONE,i can see a lot of people trying very hard to understand what the issue is, a few of dreamdiesel's post explains the issue the way i see it.

A few pointers to remember here :
1. The layer shows up only where the wiper blades wipes
2. New Bosch Wipers didn't work (for me at least)
3. All the AC/De-frost/Circulation Modes/Window lowering tricks didn't work.

OK Here goes my experience.

I spent a lot of time cleaning the windshield this (sunny) morning and GUESS WHAT. i just put some plain water and wiped it quickly with a clean cloth. i could see the milky layer from the outside of the car which i usually see from the inside.

I asked one of my friend to do the same while i sat inside the car and watched. It was the same milky layer which stays for 2-3 seconds and clears off which i see during the rains. So, No Wipers,no AC,no defrost mode, NOTHIN.

Please post in some suggestions on this one.

Note from the Team-BHP Support : Please take the time to use proper punctuation as per Team-BHP rules. Avoid...typing...like...this. Thanks.

Last edited by Jaggu : 11th October 2008 at 12:46. Reason: Stop ... typing ... like ... this
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Old 30th September 2008, 00:42   #119
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something wrong with your surface?

try putting rain-x original (or similar, aquapel etc) and buff it well, may be 2-3 coats. that will change the surface definitely.
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Old 6th October 2008, 21:47   #120
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Thumbs up Car Windshield misting probelm

Hi everybody (esp. rajan),
I am a newly registered member. i was reading through the windshield misting/fogging problem and it seems everyone has already suggested to "switch on a/c in outdoor mode... or turn up the heat and put the windshield defroster.... etc etc"
The general pyhsics here is to maintain a similar indoor temperature as the outdoor temperature when raining. But, if it is raining too heavy and it is too cold outside.. plus your a/c not very efficient...plus you have more passengers breathing & making it warmer inside... then your last option is to turn up the heat and use the windshield defroster to dry away the away from inside.
But the trick here is to really understand what your problem is? Ask yourself these questions....
1. Is fogging/misting forming on the inside? Can u write on windshield with your dry fingers from inside?
If yes, your problem is a common misting/fogging. Just follow the solutions above.
On the contrary, there is a similiar problem, which many people misunderstand it to be the common misting problem. You can see the symptoms like...
1. Misting/foggin stain for 1-2 sec just when the wiper wipes.
2. Try write ur name with dry finger from inside. It will have no effect.
3. You see it more on slight drizzles than on heavy rains... why? because heavy rains will continuosly pour down and make the stain marks wet, which then becomes invisible. These mist like stain marks are seen better on drying conditions.
Ever wondered Why did all this happen to you?
well Did you recently have a wax polish or teflon coating done? did the vendor use any products for polishing your windshield?
I am asking this because i am one such victim. Ever since that, i have researched a lot in the net and i think it may be a silicone buildup on your windshield. Internet forums shows people supporting and also blamming such products. Solutions are to use alcohol or ammonia based cleansers to clean. I tried glass cleaners, dish washers (pril) bcoz they are good degreasers , petrol, etc but to no avail. It is almost 10 months now and it still exists.
This clogging is not due to a worn out wiper. A worn out wiper will leave streaks of water on the windshield.
Here is the ultimate test...
Go for a self car wash on sunlight. And use a new, nice, clean and thin bladed table wiper (a kind of wiper blade thats used in restaurants. wet your windshields and wipe it with the table-wiper. YOu can see these stains very cleary. Do the same on a normal car without this problem.. the results would be different.
Going to dealer will not help as they are not intelligent enough to know this... and even if they are, they will make a fool out of you.... unless your car is a merc or a bmw
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