It’s that time of year again, the nights draw in, the weather turns chilly and your car turns into an icebox, literally.
We’ll all be out there in the bitter cold doing our best to get the car into a state safe to drive, some armed with credit cards scraping away, others with kettles of boiling water….but whats the best way?
There are 3 main ways to get rid of ice and frost from the windows of your car:
- Melt the ice either thermally or chemically and then prevent it from refreezing.
- Remove the moisture from the screen altogether
- Stop the moisture getting on your screen in the first place.
The are numerous ways you can melt the ice, here are some with their good and bad points.
- Boiling Water
Simply melt the ice away with a kettle full of boiling water, really good for getting rid of ice, but not so good for you windscreen. Add boiling water to an ice-cold screen and your beloved car could be the victim of Thermal Shock. In short, parts of your windscreen may heat up faster than others, expand, warp and eventually shatter, cascading the inside of your car with glass and ice meaning you will spend longer waiting for Autoglass to arrive than you would have done clearing the ice.
- Warm/Cold water?
Unlike using boiling water, tepid or cool water will melt the ice effectively without the heightened risk of thermal shock. All good you’d think. However once the ice is melted, unless you remove the moisture or apply heat or chemicals to keep it defrosted it will simply start to refreeze. You have to remember though, it’s not just the moisture from the windscreen that’s freezing this time, it’s also the jug of water you’ve just poured over. Who knows where that water has seeped, into your locks, all over the hinges, your accelerator likage, your mirrors, even dripped through and onto the floor under the car where it will form a lovely ice rink once you’ve driven off.
- Salt Water
Like the warm water above this will effectively remove the ice from your windscreen, it will also prevent it refreezing underneath you car, and may even go some way to keeping the footpath clear for pedestrians. However, salt is also one of the main causes of rust and corrosion on cars, and by pouring salt water over your windscreen and letting it drain through you are in effect getting salt into all the teeny tiny places you wouldn’t want to get salt to get to.
The classic can of de-icer, the trusted gift for that awkward to buy for gentleman at christmas. De-icer works by altering the freezing point of the ice on the windscreen, usually the de-icer will contain Methanol diluted with water, you spray it on, it combines with the ice and melts it, then the methanol evaporates and the water left refreezes. A can of De-icer (unless you buy super strength industrial stuff) is simply not man enough to do the job properly by itself. A minor side note regarding De-icer is the environmental impact, may not be huge but there’s a reason why many airports collect and process their deicing liquids prior to disposal.
By far the best method of melting ice is by applying heat. Starting your car and setting the blowers to direct warm air to the inside of your windscreen will warm the glass gradually and melt the ice from underneath allowing it to just fall away. The problems with this method? other than the time it takes there are quite a few. The cost, having your engine running uses fuel, which costs money, you may not think it would cost that much, but 20 minutes of idling every morning for a week will soon use up a fair bit of petrol. Wear and tear on the engine as well, engines aren’t really designed to idle, they are intended to run at higher revs and so just letting your engine idle doesn’t distribute the oil effectively and will increase the wear and tear your engine undergoes. There’s also the security aspect, unless you’re going to be with your car the whole time, it’s a prime target for thieves, an unlocked vehicle with the keys in it and the engine running…no chance of an insurance payout on that one. One point about this method, if you have air conditioning, use it. The AC filters and dries the air out and so speeds up the process, of course it will increase the fuel used and wear on your car.
- External Heat Sources
Any kind of heat will help to melt the ice, the important thing is to get rid of it once it’s melted. Of course this has safety implications and also the hassle involved. Is it safe to trail the flex of a hairdryer across your driveway to de-ice the car? Or if you’ve warmed a towel on the radiator and laid it across your windscreen what do you do with it when you take it off?
Melting certainly makes the job of removing the ice easier, but that little nugget is the crux of the matter, whatever you do, the ice has to be removed and melting alone just won’t do that. Thats where squeegees and ice scrapers come in. Rather than tottering around on slippery surface with jugs of water, spraying chemicals that will damage your car or the environment, or burning expensive fuels to get your car clear, you could always rely on Elbow Grease.
Ice scrapers are cheap, you can pick them up virtually every where, and they now come with all sorts of fancy gimmicks. Some are heated (pointless as the scraper isn’t in contact with the ice for long enough to melt it), some have gloves attached, some have many different edges for all sorts of different tasks, some are just flat bits of plastic. They all do the same job. The scrap the ice from the windscreen and so remove the problem immediately. No worrying about where it will refreeze, whether it will damage the environment or how much it will cost you. Liberal application of elbow grease and a scraper will have your car clear and safe, but it is hard work, and it does take time.
So which of the above is the best method to de-ice your car? they all have their pros and cons and it’s up to you which you are happy with. I usually set the blowers going and then start scraping, by the time I’ve scraped the side windows the windscreen has defrosted enough to use the wipers, and as a bonus the inside of the car is a little warmer. I personally don’t trust de-icers, they are a very quick fix, but they are also very temporary, unless you have some method of stopping the moisture refreezing they are no good.
There is another option though. Stop the ice forming on your windscreen in the first place. Short of parking in a garage or moving to Australia, the simplest way is to put something on your windscreen of a night, the ice will form on top of it and then you can just peel it off in the morning. For best results use something non absorbent (or you may find it frozen to the glass) and remember it’s going to get dirty so make sure you have somewhere to put it once it’s removed. You can also buy aerosol ice preventers as well, some of them coat your windscreen with de-icer to try to stop the ice forming, others cover the screen in foam so the ice forms on top making it easy (if a little messy) to remove. Alas these options are usually more expensive, involve dumping more chemicals into the environment and are dependant on there being no precipitation to wash away the product. Good luck on that last bit if you live in the UK.