Will warm water in winter crack your paint?

[adreed24]

I heard this story years ago and I want to know if there is any truth to it. Here it is:

In the cold, winter months, when the surface of your car is cold, you should not try to use warm, or hot, water and car soap, to wash your car.

The reason is, that the temperature difference between the cold paint and warmer water, will cause the paint to crack, and eventually come off in pieces, like a puzzle.

Anyone ever heard this before?

Any truth to this, or is it one of those car myths?

Thanks in advance!

[Jngrbrdman]

It is absolutely true. I grew up in Idaho in a valley that got down to 30 below zero on a regular basis. They wouldn't even close schools until it was 20 below because it happened too regularly and we would probably have had to close school for 5 or 6 weeks out of the year. Some really bored people took delight in throwing thermoses of hot water on windshields when it was really cold outside. You should have seen those suckers explode. They wouldn't explode like a bomb or anything, but the entire windshield would totally shatter. Sometimes it would even blow right out of the car. I have done it to a couple beater cars in the junk yard, but never to one that was drivable. Anyway, you could see the effects of someone throwing warm or hot water on a car in the spring time. Anytime something is cold and then heated to quickly it will shatter. Cold causes something to expand. Warming it up too quickly will cause it to crack because it the warmed areas will pull away from the cold areas. It is a fact of nature. The same thing happens when you put ice cubes in water that is warmer than the ice. You'll hear them crack. Yes, pouring hot water on a paint is a sure way to crack the paint. It is a sure way to shatter glass too, so don't even think about it.

[adreed24]

If this is true, which I'm sure it is, then, at what temperature, in the winter time, do you NOT wash your car?

I live in Maryland, so it doesn't get super cold here, but it can get below freezing.

I guess you just have to find the warmest day, during the winter, to do it and watch your water temperature.

[The Fuzz]

I don't know what cold weather is to you guys, but 70 degrees comes around and I pull out the parka. Everybody should retire to Florida...

I would probably just wait for a sunny day if you need to wash your car in the winter. Chances are that if it is cold enough for water to crack your paint, then the water would likely freeze on the surface before you had time to finish the job anyway. I wouldn't suggest washing your car if it is at all colder than 10 or 20 degrees above freezing just to be safe. If it is 30 degrees outside and you just need to wash the car then only do so if you can get it into a wash bay where the temperature is above freezing. I would guess that many detail shops would be able to accomodate that. Freezing temperatures are not times to be washing the car in your driveway. Back when I lived in Alaska I just drove with a messed up car and didn't worry about it. Now that I am in sunny florida I can wash that primer gray anytime I want to.

[pappy]

Originally Posted by The Fuzz

I don't know what cold weather is to you guys, but 70 degrees comes around and I pull out the parka. Everybody should retire to Florida...

haha then you are the kind of person i laugh at when i go on vacation down there.

[Poorboy]

Originally Posted by The Fuzz

Back when I lived in Alaska I just drove with a messed up car and didn't worry about it.

Was that when you lived with your brother Jim? :angel_not

[The Fuzz]

Did I tell you about Jim? He is kind of the Fuzzard family secret. We don't talk about him much. He is just not smooth with the ladies...

[Poorboy]

Originally Posted by The Fuzz

Did I tell you about Jim? He is kind of the Fuzzard family secret. We don't talk about him much. He is just not smooth with the ladies...

Yeah...Jim's the guy who likes to live in close quarter's with very tight security :ohmy:

[The Fuzz]

I wouldn't say that he likes it.... That man is about as bad with jail breaks as he is with the ladies. Good thing too. I'd hate to have him out in the free world giving the Fuzzards a bad name.

[Beemerboy]

Originally Posted by The Fuzz

I don't know what cold weather is to you guys, but 70 degrees comes around and I pull out the parka. Everybody should retire to Florida...

Fuzz....I can agree with you on the cold weather my wife wants to break out the storm doors if it drops below 50 here in CA