Frozen windshield - deicing with hot water

mitsubishi
galant

#1

I’ve recently moved to western Washington from Southern California and having to scrape icy windshields is a new (and very painful experience). How risky would it be to pour hot water over the windshield rather than using a scraper. I’m afraid it would crack the glass if the water is too hot, but there must be a “safe” temperature.


#2

While pouring warm (not super hot) water on a windshield which is merely western Washington cold is probably not going to crack it, I would strongly suggest you just invest in a nice ice-scraper. Scraping the windows with a decent scraper should take a minute or two tops-- probably less than the time it takes to bother with the tea kettle.

I personally like the scrapers with the copper blades.


#3

I would not use warm water let alone hot. They make ice scrapers for that kind of thing. BTW most cars will warm up in a few minutes and will start warming the window without any outside help. Letting the car warm up itself will mean the engine will also be a bit warmer by the time you move out into traffic.

Note: I is still best to drive the first few miles at reduced speeds (Avoid I-5 … OK during rush hour you can do I-5 as it will be nice and slow). You need to allow the other parts of your car, like the suspension system to warm up also before driving at freeway speeds.


#4

After you crack and replace 2-3 windshields post back on correct temp-get a good scrapper!!


#5

Spray some of the winter (-20F) windshield wiper fluid on your windshield and let it soak for a few minutes. This will get the ice off.


#6

I’ve seen a windshield crack when hot water was poured on it.

I’ve never seen one crack when warm water was used, however I have heard enough stories about windshields cracking with warm water that I would never use it.

As others noted, invest in a good scraper and let your car warm up for a few minutes so your defroster can help.


#7

If it isn’t too cold and the ice on the window shield isn’t too thick, you can use the windshield wiper sprayers to knock the ice clear. In my experience, this only works down to maybe 20F. Other than that, warm the car up until you have a reasonable clear area. Then maybe you can finish the job with the windshield washers.

The windshield washers will not help much with ice on the inside of the windshield.

And sometimes, you just have to scrape/chop/hack the ice off.


#8

I wouldn’t do it. In addition to the risk of cracking the windshield, you’re going to get a lot of water on the wipers or the area where the wipers sit, which will freeze up and cause other problems.


#9

Think off it this way,are any of your neighbors throwing hot water on their windshields? no, I didn’t think so.


#10

Here’s a simple solution: Turn your defrosters on high and wait for a few minutes. Ice scrapers tend to scratch the glass and using the windshield washers just wastes fluid and chews up the wiper blades.


#11

remember your engine must be warmed (in order to provide the warm air to effectively loosen the ice) and now we get into the “letting the engine idle to warm up argument”


#12

there are windshield covers you can use…also remember to lift your wiper blades before it gets icy…you can damage motor if you turn on wipers and blades are frozen to glass…


#13

I have found the ice scrapers with brass blades work extremely helpful.


#14

I’d like to chime in with my experience of having lived in both the South (Tennessee/Georgia) and North (Minnesota).

The most important thing to do in your situation is invest in a set of winter wiper blades. Every parts store in snowy states will carry them. Winter wipers are designed with a stiffer rubber blade and a plastic or rubber wrapping around the wiper arm that prevents ice from building up and freezing the wiper onto the windshield.

Even if you somehow avoid cracking the glass, the water build up on regular wiper blades will turn to ice almost instantly. An iced wiper will end up either ripping the blade out of the arm and gouging a stripe across your windshield, or burning out your wiper motor since modern wiper motors won’t shut off until they complete at least one full sweep.

Secondly, switch to a cold weather wiper fluid (-20F or lower) as soon as the first snow falls. Like centerfield9 said:

Spray some of the winter (-20F) windshield wiper fluid on your windshield and let it soak for a few minutes. This will get the ice off.

Finally, the only way to completely avoid having to scrape ice is to never park outside of a heated garage. Since this is virtually impossible, find a scraper with a good blade and a nylon brush for clearing off the top layer of snow.


#15

I agree with “mshugna” Is it possible to leave a piece of cardboard over the windshield. They also make windshield covers. Used each for many years with good success here where icy windshields is the norm. Saves lots of $$$$ and aggravation with a little more pre inconvenience.


#16

I used to do this all the time in my 70 vw micro bus. I had no heat so I used enough water Hot to the touch but not boiling to warm the windshield before my 20 drive to work. No cracking. Tempered glass is REALLY tough not like a cocktail glass. They are built to withstand a rock or road debris at highway speed.


#17

There is no serious risk of cracking a windshield from this. Rocks bounce off this glass. It is already tempered and is tough as nails.


#18

Yes, there is a risk of cracking the windshield. Rocks USUALLY bounce off. They sometimes crack the glass, though. And if you get a little crack…even one you can barely see, this temperature change can cause it to split clear across the windshield.

That doesn’t make it unsafe. People in Alaska drive with windshields criss-crossed with cracks all the time. I think it’s technically illegal, but no one cares. The windshield will still hold together. (they’re made of multiple layers, and usually only the outer layer cracks.)

However, in some jurisdictions, you’ll get a fix-it ticket for that (because people are stupid, including cops and legislators.)


#19

Don’t do it, even if it works on the windshield you now have created an ice patch on the ground where the water runs off the car. Just get a good scraper. I had an outdoor car for 12 years in Anchorage after work. Go out, turn on the car, defrost on high, scrape all windows (front/rear/side) get in, drive off.


#20

No safe temp. Even if you’re down on the Sound, the very few days you will want to do this will be the very few days it is cold. And on those days, the water quickly refreezes to a uniform slippery sheen that really IS hard to get off. Big danger is the glass movement caused by rapid temp differences will find the tiniest crack in the tiniest chip you have not noticed. Then it’s a really big crack and new windshield. If scraping is difficult for you, go to any of the Big Boxes and get the spray can of windshield deicer.