A word of winter driving advice

[Zak33]

It's simple.. but it's easy to forget

before you get out of your car for the night..

TURN OFF THE WIPERS....

If it was pouring down when you got home.... turn off the wipers before you get out.
If it was gently snowing as you pulled in... turn off the wipers before you get out

When you get back in... be careful to not push the wiper control arm up before starting it.

This last week... with frozen screens and wiper blades stuck to the glass.. I have seen COUNTLESS people with torn wiper blades..and a few very sad ones with damaged wiper motor linkages..... where the wipers were stuck and when the car was started in the morning, they activated immediately.

Torn wiper blades ruin your visibility and cost money to replace.
Damaged wiper linkages or worse.. damaged motors...cost a LOT and reneder your car un-driveable.


So... tell you mum/dad/boyfriend/girlfriend/aunty...

turn the wipers OFF before you get out and when you restart the car in the morning.... WARM THE SCREEN WITH THE FAN before turning on the wipers.
DONT use the wipers to scrape ice off... dont do it.

case closed.

[abaxas]

Just pour some tepid water over the windscreen in the morning.

Job done. Wiper anxiety averted.

[malarkey95]

Nice salty water on the screen boiling water I heard weakens the screen not sure if true. Can't remembered why beat

[Spreadie]

I saw my neighbour exit his house with a freshly boiled kettle one winter's morning, and watched with fascination as he poured it over his windscreen.

I heard the crack from across the street.

I'm pretty sure he heard me laughing too.

[bledd]

Just pour some tepid water over the windscreen in the morning.

Job done. Wiper anxiety averted.

Normal cold tap water works best. Warm water freezes quicker than cold water.

[ik9000]

Warm water freezes quicker than cold water.

Rubbish! Not sure the science stacks there. Water has to be cooled to the freezing point for freezing to take place, and it must then lose energy (latent heat of freezing aka latent heat of fusion) to its surroundings, or have that energy removed from it, for the freezing to take place. The hotter the water the more it must cool (loss of internal energy, specific heat etc) to begin to freeze. i.e. more energy extraction required. In a given circumstance with a fixed energy flow it must therefore take longer for warm water to freeze than cold water.

Now if you meant hot water is quicker to evaporate away - then you'd be right.

[kalniel]

Or just add some glycerine.

[DanceswithUnix]

Rubbish! Not sure the science stacks there.

He is sort of right: https://en.wikipedia.org/wiki/Mpemba_effect

However, as the kettle "experiment" above (not sure you can use that word when the outcome is fairly certain ) shows, at the sorts of 90 degrees C temperatures required you don't have a usable windscreen any more so it seems academic.

Windscreen do naturally get some thermal abuse, if you have a heater blowing at the bottom of the screen and falling snow cooling at the top that is far from ideal for thermal stress. Same with water falling on a hot screen in summer. It happens, the screen rarely breaks.

The key is gradual change, you don't have to get the screen up to temperature in under a second. I use luke warm water, pour it all over so it acts on as much of the screen as possible, go back and get a refill. The aim is to get the glass warmed throughout just enough that the heater will take over before it freezes over again.

Or, like this morning, I decide I would rather walk to work

Good advice from the OP though. Many years ago I had smoke pouring out from under the bonnet of a car from the stalled wiper motor. It was a Morris Ital, so no loss

[ik9000]

He is sort of right: https://en.wikipedia.org/wiki/Mpemba_effect

from that very article:

The phenomenon, when taken to mean "hot water freezes faster than cold", is difficult to reproduce or confirm, because this statement is ill defined

insufficient detail for the claims to be replicated

it is not clear [what definition] "freezing" refers to

there may be many circumstances in which the effect is not observed

A quirky event that is unpredictable, unreliable, and IF (and it remains a big IF) under a very strict (and uncommon) definition of freezing a certain very specific (and abnormal) set of conditions are artificially created and maintained, then the hotter water may "freeze" first - with freezing meaning a different thing from which most would commonly accept as freezing.

This is one of the questionable QI-style "facts" that isn't actually a fact and simply misleads the general public into accepting as certain things that really aren't that clear cut.

It's probably worth comparing this to a similar situation: Given the right parameters when measured in a very specific way, one can demonstrate that the earth is flat!

[herulach]

Having a clean & prepped windscreen helps a lot as well. Mine needs redoing, but a coating of water repellent + about 2 litres of tap water means a pretty much ice free windscreen in no time.

[Ttaskmaster]

Buy a can of de-icer spray, ya bunch of cheapskates - Even my budget-conscious missus forks out on that!!

We had a presentation on Winter Driving Safety earlier this week.
Got told all sorts of tips about how I ought to drive a car... They got really upset when I excused myself and walked out to do some more urgent work, on the basis that I don't actually *have* a car and seemingly even more upset that I would dare to ride a motorcycle... so I had to sit back down, whereupon I asked all manner of awkward questions regarding safety procedures that cannot apply to bikes.
Apparently I should still not clear the windscreen that I don't have using the windscreen wipers that don't exist and instead use the heater that isn't fitted... and the best part is that I should *still* correctly de-ice the car that I don't own, even though it overnights in a garage and physically cannot get any frost on it!!

There are some seriously 'special' people in our company...!!

[ik9000]

There are some seriously 'special' people in our company...!!

Reminds me of this!