I need to ask someone a quick question...maybe you'll know the answer. It is 15 degrees here in Columbus Ohio. My car is very covered with a whitish haze of salt. I would like to rinse of the salt with either a power spray rinse or even more effective would be to run it thru a touchless power wash...soap hot water and rinse etc. I am not sure if the sudden change in temperature of the water would hurt the paint (microcracking) . Do you have any ideas. I am leaning toward just using a spray wand and rinsing the salt off...cool water only. Thanks.:nixweiss
Washing in 15 degrees.???
- Thread starter Ikabob
- Start date
I am in Cleveland and washed my car yesterday (see the thread called A Little Too Cold to Detail in the Autopia forums). There is a product called ProtectAll Quick and Easy Wash that you can use to actually wash your car without having to rinse it afterwards. Many people on the board use it and it works great. If you go to www.protectall.com and search the retailer database there are at least 4 or 5 places in Columbus that sell this stuff (I got mine in Brunswick and it was under 8 bucks).
I rinsed the car off at one of those car wash bays, then parked it on a sloping driveway with the sun shining on it. Then used the QEW one panel at a time, wiping it immediately with a clean MF waffle weave towel. It did a spectacular job. I used very warm water when I mixed the QEW, and had a separate bucket of warm water for rinsing my lambswool mitt.
I rinsed the car off at one of those car wash bays, then parked it on a sloping driveway with the sun shining on it. Then used the QEW one panel at a time, wiping it immediately with a clean MF waffle weave towel. It did a spectacular job. I used very warm water when I mixed the QEW, and had a separate bucket of warm water for rinsing my lambswool mitt.
I agree with TurboCat. Get some QEW. :up If your car is super dirty go spray it off real quick and a Do It yourself place. I recently started using QEW using the same process and it's amazing. And I can plug in my little heater and do it in the garage. I think this morning it was 2* with a high of 15* expected.
TJ
TJ
Lowejackson
New member
Washing with hot water is to be avioded, it can crack glass and may possibly cause a problem for the paint. Also hot water will freeze quicker than cold water. If you cannot always wash, at least rince the crud off. This is why many use a polymer base to protect the paintwork over the winter months.
Steven
Steven
nate010753
New member
Guys I washed my car yesterday it was so cold that the beaded water was freezing before I could dry it off. And I was moving quick!!!!!
autohubgroupph
New member
How would hot water freeze quicker than cold water? The greater the difference in temperature, the longer it would take to reach a steady temperature.
Anyway, I like the touchless car washes for below freezing cleanliness, but the key is the blow drying. Otherwise, there is a greater chance of you getting frozen in or out of your car. After the jet dryers, I have to clean up just a little with a towel. No problems after 4 winters for one of my vehicles.
Anyway, I like the touchless car washes for below freezing cleanliness, but the key is the blow drying. Otherwise, there is a greater chance of you getting frozen in or out of your car. After the jet dryers, I have to clean up just a little with a towel. No problems after 4 winters for one of my vehicles.
Hot water will freeze quicker than cold water. Back in the old days before ice makers in the freezer when you had to use the old ice trays I was always told to use hot water. It made ice faster and came out of the trays easier.
I love my QEW so much I went back and got a gallon. Many RV camping stores carry the ProtectAll products .... many also carry 303 protectant as well.
I love my QEW so much I went back and got a gallon. Many RV camping stores carry the ProtectAll products .... many also carry 303 protectant as well.
> Hot water will freeze quicker than cold water
Actually quite, the opposite, it will take longer for it to reach the freezing point. Hot water will loose a given ammount of heat quicker than cold water (due to the temp differential) when they are both placed in the same temp (a freezer or outside), but they will both freeze at the same temperature. The starting temperature will not alter the freezing point of water.
As for ice made from hot water coming out of the tray easier, that might be true (water freezing at a slower rate will stick less). Same goes true for cooking food, heat it fast and it will most likely stick, heat it slow and it usually won't.
But as others have pointed out, hot water can cause damage....to a point. I think a rapid change in temperature can cause damage. If you use warm water (say 70-80 degrees) I'm not quite sure that there is enough thermal mass in the warm water contained in the wash mitt to rapidly change the temp and do any damage. The important thing I would think is not to use HOT water, just warm enough to keep your hands from freezing.
I guess the same could be true in reverse when the car is in the sun or really hot weather the paint could easilly be well over 100 degrees. The water out of the hose is probably around 55-60 degrees which would make around a 50 degree drop. That never seems to cause problems.
Just a random thought.
Mike
Actually quite, the opposite, it will take longer for it to reach the freezing point. Hot water will loose a given ammount of heat quicker than cold water (due to the temp differential) when they are both placed in the same temp (a freezer or outside), but they will both freeze at the same temperature. The starting temperature will not alter the freezing point of water.
As for ice made from hot water coming out of the tray easier, that might be true (water freezing at a slower rate will stick less). Same goes true for cooking food, heat it fast and it will most likely stick, heat it slow and it usually won't.
But as others have pointed out, hot water can cause damage....to a point. I think a rapid change in temperature can cause damage. If you use warm water (say 70-80 degrees) I'm not quite sure that there is enough thermal mass in the warm water contained in the wash mitt to rapidly change the temp and do any damage. The important thing I would think is not to use HOT water, just warm enough to keep your hands from freezing.
I guess the same could be true in reverse when the car is in the sun or really hot weather the paint could easilly be well over 100 degrees. The water out of the hose is probably around 55-60 degrees which would make around a 50 degree drop. That never seems to cause problems.
Just a random thought.
Mike
I was told that business about the hot water and the ice cubes too. We tried it and the hot water didn't freeze quicker. I think the reason that the ice cubes come out easier is because the hot water often doesn't have as much dissolved air. The dissolved air seems to come out of solution when freezing and make bubbles, which take up more space than frozen water. The ice cubes made with hot water had fewer bubbles and cloudiness than the ones made with cold water.
Lowejackson
New member
The reason I said about the hot water freezing is during the trip to work, that morning, there was talk about this very experiment, on the BBC news programme. They had set up a series of dishes containing water at different temps and were checking to see which (if any) would freeze quicker. The hot (boiling) water won. I am trying to find out who conducted the experiment and will report back. In the meantime here is a link from New Scientist http://www.newscientist.com/lastword/article.jsp?id=lw236 on this very topic.
Shame on you all for doubting me :nono
Steven
Shame on you all for doubting me :nono
Steven
Steven,
Thanks, that was an interesting article. It is technically correct, but the theries really only apply to stagnant bodies of water in a container.
With stagnant water in a container, the cooling of the hot water causes the cool water to sink, thus exposing the warmer water to the surface (exposed to air) and allows it to cool, sink --->repeat, you get the idea.....convection. Also, if the container is placed in the frost of a freezer, or in snow, the warm container (water) will melt some of the frost which will later freeze against the container and make a better thermal contact (and help it freeze faster).
However, I don't think any of this really applies to us with the thin film of water we apply and/or streams of water we use. This water is constantly in motion, or too thin of a film to really have convection significantly affect it.
I still submit that for our use, warm water will not freeze faster than cold water. At least not significantly enough for me to notice or care. But it sure will keep my hands from freezing
Mike
Thanks, that was an interesting article. It is technically correct, but the theries really only apply to stagnant bodies of water in a container.
With stagnant water in a container, the cooling of the hot water causes the cool water to sink, thus exposing the warmer water to the surface (exposed to air) and allows it to cool, sink --->repeat, you get the idea.....convection. Also, if the container is placed in the frost of a freezer, or in snow, the warm container (water) will melt some of the frost which will later freeze against the container and make a better thermal contact (and help it freeze faster).
However, I don't think any of this really applies to us with the thin film of water we apply and/or streams of water we use. This water is constantly in motion, or too thin of a film to really have convection significantly affect it.
I still submit that for our use, warm water will not freeze faster than cold water. At least not significantly enough for me to notice or care. But it sure will keep my hands from freezing
Mike
Lowejackson
New member
I mostly agree, but as "Newton showed 300 years ago that the rate of heat loss from a system is proportional to the temperature difference between it and its surroundings", so by using hot water a cold car with the ambient temp at 15 degree, the water could well freeze quicker than by applying tepid or cold water. Not forgetting that not all the water will be moped up during drying with a towel. You will still get water between panels, in drain pipes etc.
After paintwork comes all the glass, the risk here is clear. I always remember seeing someone pour boiling hot water onto a frozen windscreen and then watching it shatter
:nono
Steven
PS: The New Scientist Last Words is a very enjoyable series of common questions.
After paintwork comes all the glass, the risk here is clear. I always remember seeing someone pour boiling hot water onto a frozen windscreen and then watching it shatter
:nono Steven
PS: The New Scientist Last Words is a very enjoyable series of common questions.
I really enjoyed reading the above discussion regarding hot water on a cold car surface. But I also read in some of the other postings about members who have washed their car in freezing weather using the hot water hookup from their washing machine. Are you saying this is a no no?
DETAILKING
New member
I would use 60-70 degree water max. Hot water on a cold car is a nono. If anything you risk a high chance of cracking the glass.
DETAILKING
New member
I have read about the hot water freezing phenonemon in the past. I agree with its theory, under certain controlled conditions. It might go against common reasoning, but if you work it out step by step it kind of makes sense.....
For a given amount of mass, the total cooling duty in BTU/hr to freeze water is composed of a few factors. First there is sensible heat.......this is the cooling requirement to bring the water from its initial temperature to it's freezing point (~32 °F). Then there is latent heat. Latent heat is the cooling duty required to go from liquid to solid @ its freezing point temperature (32 F). Quick analysis tells us that if the water is warmer, the sensible heat (cooling)requirement will be greater thus requiring more cooling duty (BTU/hr).
Now lets take a standard heat transfer equation. DUTY (BTU/Hr) = U*A*DT, where U is the heat transfer coefficient, A is the contact area, and DT is the differential temperature. It's easy to see that if you had a tray of warm water and cold water in the freezer in similar trays, that U and A would be the same. Since the warm water is warmer, the DT is greater relative to the cold ambient conditions of the freezer, hence the amount of duty (cooling) that is absorbed is at a greater rate.
When the cold water tray forms a skin, that acts as an insulating layer and the warmer water in the center of the tray takes longer to cool and freeze. Since the warm water is absorbing heat (cooling) at a faster rate, it cools more homogeneously, and in the right conditions will freeze at a faster rate......
Hope this makes sense!
For a given amount of mass, the total cooling duty in BTU/hr to freeze water is composed of a few factors. First there is sensible heat.......this is the cooling requirement to bring the water from its initial temperature to it's freezing point (~32 °F). Then there is latent heat. Latent heat is the cooling duty required to go from liquid to solid @ its freezing point temperature (32 F). Quick analysis tells us that if the water is warmer, the sensible heat (cooling)requirement will be greater thus requiring more cooling duty (BTU/hr).
Now lets take a standard heat transfer equation. DUTY (BTU/Hr) = U*A*DT, where U is the heat transfer coefficient, A is the contact area, and DT is the differential temperature. It's easy to see that if you had a tray of warm water and cold water in the freezer in similar trays, that U and A would be the same. Since the warm water is warmer, the DT is greater relative to the cold ambient conditions of the freezer, hence the amount of duty (cooling) that is absorbed is at a greater rate.
When the cold water tray forms a skin, that acts as an insulating layer and the warmer water in the center of the tray takes longer to cool and freeze. Since the warm water is absorbing heat (cooling) at a faster rate, it cools more homogeneously, and in the right conditions will freeze at a faster rate......
Hope this makes sense!