[sreenivass]

I recently drove in rains for over 10 hours. The technique I employed was Blower Full, direction knob towards windshield and A/C control in hot/warm/ full position. I also opened the windows whenever possible. Over time I could get a feel of what position in hot zone works in the current conditions, once set I did not have to change much for quite a few hours. There was a situation once (before I could get control of the situation by adjusting controls correctly) fog started forming and covered the windshield completely in less than 5 secs. I stopped the car aside and started after clearing the fog.

Setting the heater to full definitely works, it will be hell for passengers and driver too.

[caliper]

I'm the thread originiator. I recently took the same trip as I referenced in the first post.

This time, I took greater care in noticing what was happening. After the car was sitting for a few hours in the evening/night, there was no fog on the outside. Amazingly, though, 1 minute after I got in, the outside was covered with fog! I'm not quite sure about why, but there you have it.

This time, I did not direct any air to the windshield. Rather I just directed it on the passenger compartment (the first blower setting, where the air is blowing on the picture of a person). I set it on full blast, A/C on, outside air, cold temperature, and opened the driver window 2 inches. It took about 5 minutes, but the fog totally cleared out.

This time, the windshield was totally clear without having to engage the wipers or any sense of danger. I alternately ran and turned off the A/C as desired, and even used recirculate mode without problems.

I think this underlines the point that you should make sure your windshield is clear after you get seated, and before you take off instead of trying to hope it'll clear on the road, which is dangerous.

By the way, I had also washed the windshield with hair shampoo before heading out as recommended somewhere else. I don't know if that was necessary, since the back windows (which I didn't wash) were also fog-free.

[Venkatesh.C]

Originally Posted by sreenivass

I recently drove in rains for over 10 hours. The technique I employed was Blower Full, direction knob towards windshield and A/C control in hot/warm/ full position. I also opened the windows whenever possible. Over time I could get a feel of what position in hot zone works in the current conditions, once set I did not have to change much for quite a few hours. There was a situation once (before I could get control of the situation by adjusting controls correctly) fog started forming and covered the windshield completely in less than 5 secs. I stopped the car aside and started after clearing the fog.

Setting the heater to full definitely works, it will be hell for passengers and driver too.

VERY TRUE. THere is no one formula for this. You just keep playing the fiddle the knobs game with this windshield fog thing.

[1100D]

I have had similar experience with the Ikon will share the observation.

Is the fogging is happenning ont he outside of the front windshield only? Now when you have the AC on, automatically the interior is dehumidified and you would not have internal condensation, but the external condensation is happenning due to the windshield itself getting cold and the dew forming onthe outside as outside air is humid.

2 things can work, temp setting towards warm,hot, which will make the interior uncomfortable or direct the air-flow away from the windshield. I.e use lower outlets. For me it works even when its very hot outside and about to rain.

The position blower control that shows the windscreen symbol is simply passing the cold air at the windshield coolong it to cause the mist outside. So avoid that setting you'll be fine.

[sanchits]

guys...ive got a swift zxi...and beleive me it just takes 10-15 seconds to get a crystal clear windshield. i just press the front defogger button...and the blower below the windscreen clears the fog in a jiffy. i haven't seen such a efficient front defogger in any car.

[SS-Traveller]

Originally Posted by caliper

I had also washed the windshield with hair shampoo before heading out as recommended somewhere else. I don't know if that was necessary, since the back windows (which I didn't wash) were also fog-free.

Mist on the outside of the front windshield has been a problem I've also faced while night-driving on foggy highways in winter (high-humidity conditions). Do what you might with the HVAC controls, or even the defogger button on my Swift ZXi, the fog outside comes right back in 5 seconds after the wiper clears it. So I use some home-grown solutions. I fill the window-washer tank with a quarter bottle (125-150 ml) of any of the propietory glass cleaners (Colin, Mr. Muscle, Kiwi), and top up with water, when I anticipate a drive like this. A quick wash-wipe keeps the mist from forming for a few minutes, and subsequent use of the wiper doesn't let the fog come back so quickly. If you've forgotten the glass cleaner at home, try this - run the wash-wipe first, then spit on the glass, and using an old newspaper, wipe the saliva till no streak remains. Fogging on the outside is absolutely gone.

[maxj2005]

Originally Posted by SS-Traveller

try this - run the wash-wipe first, then spit on the glass, and using an old newspaper, wipe the saliva till no streak remains. Fogging on the outside is absolutely gone.

Spit?

Lets imagine you are standing in a market and spitting on your car's windshield and then cleaning it with a old newspaper.

I dont know how good this method is but sure is yukky.

[govigov]

no matter what settings i use, there is always a small amount of a/c going on to the windshield. i just put a nice little cloth (Towel) lenght wise on the a/c vents that direct the air to the windshield. bang! problem solved - no more fogging of the front windscreens.

[SS-Traveller]

Originally Posted by maxj2005

Spit?

Lets imagine you are standing in a market and spitting on your car's windshield and then cleaning it with a old newspaper.

I dont know how good this method is but sure is yukky.

Why spit when you are standing in a market? Go to a shop and buy yourself a glass cleaner! Spitting is for emergency use, when you are on a highway at 1 AM, and left the glass cleaner at home.

Incidentally, if people like us thought saliva is yukky, we'd be looking for a change in profession, and the rest of the world would end up being edentulous...

[susan3004]

@Caliper
I understand the problem of mist forming on outside the glass(and not inside, as you have already switched on the a/c settings to get rid of the same). The outside mist formation behaves like sleet and seems dificult to remove by just using the vipers. Using wind shield washer water does not help, as it is of the same temp(or a couple of degres more).
Now, what happens is that when we use water(even mixed with other sustances like colin/kiwi etc)and the wiper along with it, there is a thin layer of water on the windshield remaining as the blade moves for the first time, which transforms into ice, which in turn blocks our visibility.
The foremost part is to get rid of the same. We have already discussed and understood as to clearing the inside of the windshield. For the outside part, one of the methods is to wipe clean the surface with a warm cotton cloth(more applicaple for Gypsy/M&M users or cars not having a/c), till the time it is dried. The second method is to switch on the a/c with the heater temp to suit the requirements of the ocupants and direct the air to the windshield. The air should be circulated inside and outside air is not required at this time. Wait for a few minutes(waiting time may vary with the temp outside) and you will find the windshield clearing up from the bottom going towards the top. Donot use the wipers in the meantime and one will find that the time spent while waiting is an investment in terms of safety.
While using M&M/Gypsy in sub zero conditions and also while using the same in northern plains of India near the IB while exegengies of service force the vehicle movement these problems are common. Drivers at times have been found sticking their heads out side the vehicle after rolling down the window to have a better view.
One more thing which has not been mentioned on the thread is using RUM instead of water as the windshield washer. Rum does not freeze at subzero temps hence it cleans each and everytime.(And ofcourse it can be used as emergency rations also. Cheers)
Humidity is not the factor which is responsible for this phenomena.(Paddy fields and seacoast donot offer such low temps)
Driving insuch conditions can be challanging and hence greater care is to be taken while attempting the move in such conditions. One has to be carefull and yes, also has to enjoy the adventure.

[SCH]

Pls. check if you have kept the blower direction towards windshield and the setting is set to front passengers. If the blower blades are pointed towards the windscreen this problem will happen.

[SS-Traveller]

Originally Posted by susan3004

...using RUM instead of water as the windshield washer... to enjoy the adventure.

Even a quick wipe of the windshield with rum or whisky (and a quick swig) makes for better visibility all round, and better conditions to enjoy the adventure in. Just keep the ignition switched off after that!!!
@Mods: Hope I didn't break the "no alcohol" rule... If so, please delete.

[vivekiny2k]

does rum or any other alcohol harm the rubber wiper blades? in addition, can it be used on a rain-x treated glass?

I am told alcohol prevents snow from sticking to the glass, hence wanting to experiment.

[SS-Traveller]

Originally Posted by vivekiny2k

does rum or any other alcohol harm the rubber wiper blades? in addition, can it be used on a rain-x treated glass?

I am told alcohol prevents snow from sticking to the glass, hence wanting to experiment.

Alcohol, or any other organic solvent, will make the wiper blades harder and less supple if exposed frequently over a period of time. Even liquid soap or shampoo added to your washer bottle will do it. It'll depend on how frequently and how much.

I was not conversant with Rain-x treatment. Just googled it. Have no idea what the constituent chemicals may be. Please check their literature and tell us if possible. I don't think rain-x is available in India (except perhaps in specialty garages stocking imported stuff).

[Indian1979]

Originally Posted by caliper

I'm the thread originiator. I recently took the same trip as I referenced in the first post.

I think this underlines the point that you should make sure your windshield is clear after you get seated, and before you take off instead of trying to hope it'll clear on the road, which is dangerous.

I agree. I used to face this problem, until I start waiting and clearing the windshield completely before driving.

I use the following settings to clear: Heat Full, A/C off, Outside air, Full blower, Demister on.

After clearing was able to drive with A/c on without any adjustments. Have tried this on long drives too, never faced any issues.