Discussion
As a youth with a licence I quickly got wind of what I now believe to be nothing short of another in a long line of motoring related myths.
Pouring a kettle over iced and frosted up windows on your car at this time of year.
Many reckon that you take a kettle of boiling water and pour that over your car and you will risk cracking the windscreens. Who would use boiling water anyway - are you totally mad? What do you think is going to happen! I have certainly never used boiling water but then there is no need for the water to be boiling or even hot.
Time and again I have seen or heard people first thing in the morning scraping away for up to 10 minutes getting the frost off their windows when there really isnt any need to go to such lengths. I have always used hot water from the tap with some cold to make it slightly cooler and poured that over all my windows and lights using a plastic watering "can". Voila! 30 seconds and youre all done and ready to move off. No frozen fingers that you have to then place over the heater vents to thaw them out either. No chance of scratching the glass too.
Have you ever cracked a screen using the boiling kettle ?
Tip of the day if nothing else
Pouring a kettle over iced and frosted up windows on your car at this time of year.
Many reckon that you take a kettle of boiling water and pour that over your car and you will risk cracking the windscreens. Who would use boiling water anyway - are you totally mad? What do you think is going to happen! I have certainly never used boiling water but then there is no need for the water to be boiling or even hot.
Time and again I have seen or heard people first thing in the morning scraping away for up to 10 minutes getting the frost off their windows when there really isnt any need to go to such lengths. I have always used hot water from the tap with some cold to make it slightly cooler and poured that over all my windows and lights using a plastic watering "can". Voila! 30 seconds and youre all done and ready to move off. No frozen fingers that you have to then place over the heater vents to thaw them out either. No chance of scratching the glass too.
Have you ever cracked a screen using the boiling kettle ?
Tip of the day if nothing else
Edited by ToothbrushMan on Monday 20th January 06:20
ging84 said:
heard many people claim it happend to a friend, never to themselves
my guess is it might have been something which happened occasionally in the 70s
can't imagine it happening today with modern windscreen glass
Funny enough I had a friend at high school who said he had done it... wasn't the sharpest tool in the shed, he once though he was going to get a ticket for having a missing hubcap.my guess is it might have been something which happened occasionally in the 70s
can't imagine it happening today with modern windscreen glass
IIRC the car was a 1980-ish Mitsi Sigma though, so it could probably crack windscreens just by seeing its reflection in shop windows.
Right up my street this one.
I believe not using warm water to defrost is more likely to break screens. There are sound reasons for believing this too.
If you have a flaw such as a stone chip in your screen when you get in on a frosty morning after defrosting the outside of your screen the first thing you do is to whack the heater on hot and point it straight at the screen to stop it misting up. As the screen will be heated from the inside the inner layer of the laminated glass will expand causing stress. When cold the laminate in the middle is very stiff and as such will transmit this stress directly to the outer layer imparting a tensile stress on the flaw.
Heating from the outside with hand hot water will uniformly heat the layer most likely to have flaws in it, heat the laminate making it more pliable and demist the inner layer too.
Heated screens are the best but not an option for everyone.
I have seen the inverse happen when a customer with a Transit screen that had been sat outside in baking sun decided to wash the screen with a cold hose pipe. The outer layer of the screen cracked like I had never seen before due to thermal shock. It was so hot we couldn't sit on the dash to carry out the replacement and had to wear gauntlets to pick the old screen up, it was too hot to touch.
Just to show how stress from heater vents can cause cracks here's a picture I think makes the point.
I believe not using warm water to defrost is more likely to break screens. There are sound reasons for believing this too.
If you have a flaw such as a stone chip in your screen when you get in on a frosty morning after defrosting the outside of your screen the first thing you do is to whack the heater on hot and point it straight at the screen to stop it misting up. As the screen will be heated from the inside the inner layer of the laminated glass will expand causing stress. When cold the laminate in the middle is very stiff and as such will transmit this stress directly to the outer layer imparting a tensile stress on the flaw.
Heating from the outside with hand hot water will uniformly heat the layer most likely to have flaws in it, heat the laminate making it more pliable and demist the inner layer too.
Heated screens are the best but not an option for everyone.
I have seen the inverse happen when a customer with a Transit screen that had been sat outside in baking sun decided to wash the screen with a cold hose pipe. The outer layer of the screen cracked like I had never seen before due to thermal shock. It was so hot we couldn't sit on the dash to carry out the replacement and had to wear gauntlets to pick the old screen up, it was too hot to touch.
Just to show how stress from heater vents can cause cracks here's a picture I think makes the point.
1: boil kettle
2: make a brew
3: go outside armed with kettle and a squeegee, clear away ice and frost in minutes
4: go back inside to warm house and enjoy brew whilst watching neighbour slowly get frostbite whilst using a nectar card/ bank card/ cd case to clear ice and frost
Never had a problem.
2: make a brew
3: go outside armed with kettle and a squeegee, clear away ice and frost in minutes
4: go back inside to warm house and enjoy brew whilst watching neighbour slowly get frostbite whilst using a nectar card/ bank card/ cd case to clear ice and frost
Never had a problem.
I used slightly warm water to clear my Celica screen regularly several years ago (once when staying overnight at my parents and my dad almost sh*tting himself warning me the World would end if I did such a foolish thing) without incident except for once when after the screen was chipped and I couldn't be arsed / hadn't got round to replacing it, I cleared the screen as normal, drove to work with the heaters on full (a really cold day) and as I (slowly) went over one of the speed bumps in the car park the screen cracked from the chip to the bottom as illustrated Crossy67's photo. So I suspect it was more warm inside / really cold outside in combination with the flex or vibration of a speed bump that caused the crack, but if I'd told my old man of course he'd have said it was the water.
But there's no need to use boiling, or even hot, water.
In a country like the UK, where temperatures are seldom more than a few degrees below freezing, the water only needs to be a few degrees above freezing to do the job.
In practice, water straight out of the cold tap is more than adequate most of the time.
In a country like the UK, where temperatures are seldom more than a few degrees below freezing, the water only needs to be a few degrees above freezing to do the job.
In practice, water straight out of the cold tap is more than adequate most of the time.
I use a spray can of de-icer.
Not doing this right am I?
Either way, I have always been averse to doing this thing with hot water so rather than risk it, spray on the chemicals. And seeing as my heaters do not come on tap at nuclear heat straight away, I figure the gradual warming is no real shock.
Not doing this right am I?
Either way, I have always been averse to doing this thing with hot water so rather than risk it, spray on the chemicals. And seeing as my heaters do not come on tap at nuclear heat straight away, I figure the gradual warming is no real shock.
Garage, subtropical Brisbane. Ice rarely an issue (other than seasonal hail storms)
Burny hot leather when wearing shorts of smugglers is more of an issue
When we lived in London I used a scraper (blue) thing they that was generally handed out by vendors during the season. I always found that hot water would clear the screen but would inevitably result in a frozen screen again if the car wasn't warmed up properly so preferred to scrape. Quite anal about this too... Clearing the whole screen, not just some half hearted attempt in the middle.
Burny hot leather when wearing shorts of smugglers is more of an issue
When we lived in London I used a scraper (blue) thing they that was generally handed out by vendors during the season. I always found that hot water would clear the screen but would inevitably result in a frozen screen again if the car wasn't warmed up properly so preferred to scrape. Quite anal about this too... Clearing the whole screen, not just some half hearted attempt in the middle.
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