# Homemade windshield deicer **URL:** \ **Category:** Factual Questions\ **Created:** [December 14, 2006, 4:25am UTC](https://boards.straightdope.com/t/homemade-windshield-deicer/384078 "2006-12-14T04:25:08Z")\ **Posts on this page:** 9\ **Page:** 2
**Author:** ![MikeF](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@MikeF](https://boards.straightdope.com/u/MikeF)\ **Post date:** [December 4, 2013, 8:08pm UTC](https://boards.straightdope.com/t/homemade-windshield-deicer/384078/21 "2013-12-04T20:08:46Z")
Regular RainX makes the removal of ice much easier. If it was recently applied the ice kind of slides right off. YMMV. ---
**Author:** ![Ethilrist](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ethilrist/32/4604_2.png) [@Ethilrist](https://boards.straightdope.com/u/Ethilrist)\ **Post date:** [December 4, 2013, 9:42pm UTC](https://boards.straightdope.com/t/homemade-windshield-deicer/384078/22 "2013-12-04T21:42:37Z")
> [@Esprix](#): > > Gosh, it’s been a while, hasn’t it? 😉 Winner of the Deceptive Zombie OP of the Year award. ---
**Author:** ![bob\_2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bob_2/32/3341_2.png) [@bob\_2](https://boards.straightdope.com/u/bob_2)\ **Post date:** [December 4, 2013, 11:42pm UTC](https://boards.straightdope.com/t/homemade-windshield-deicer/384078/23 "2013-12-04T23:42:04Z")
My father made an efficient de-icer. He took a metal biscuit tin, cut a hole in the side, and fitted a lamp holder. With a 40 watt bulb inside, and left in the car on frosty nights, it would stop the car from freezing up, even when it got down to -4 or 5C. I guess that in really cold places you might have to go up to a 60 watt bulb. I typed that and then realised that those bulbs are not available here any more. Maybe a halogen? ---
**Author:** ![Esprix](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/esprix/32/7899_2.png) [@Esprix](https://boards.straightdope.com/u/Esprix)\ **Post date:** [December 12, 2013, 5:27pm UTC](https://boards.straightdope.com/t/homemade-windshield-deicer/384078/24 "2013-12-12T17:27:06Z")
> [@Ethilrist](#): > > Winner of the Deceptive Zombie OP of the Year award. Got that right. 😉 Esprix ---
**Author:** ![Leaffan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leaffan/32/299_2.png) [@Leaffan](https://boards.straightdope.com/u/Leaffan)\ **Post date:** [December 12, 2013, 5:52pm UTC](https://boards.straightdope.com/t/homemade-windshield-deicer/384078/25 "2013-12-12T17:52:41Z")
> [@anomad](#): > > I also bought the straight antifreeze, put it in a spray bottle and it was a bit slower but still freezes up again. There must be something that can be put on auto windshields that will not refreeze. There is nothing that I’ve ever been made aware of that people spray on their windshields to prevent freezing. Anyway, straight antifreeze has a higher freezing temperature than a mixture of antifreeze and water. As listed in this [table](http://en.wikipedia.org/wiki/Ethylene_glycol#Antifreeze), a 70/30 mix of ethylene glycol and water has a lower freezing point than 100% EG. (-51C vs. -12C) ---
**Author:** ![Pjen](https://avatars.discourse-cdn.com/v4/letter/p/3d9bf3/32.png) [@Pjen](https://boards.straightdope.com/u/Pjen)\ **Post date:** [December 12, 2013, 5:57pm UTC](https://boards.straightdope.com/t/homemade-windshield-deicer/384078/26 "2013-12-12T17:57:32Z")
Funnily enough, there was a Frost in coastal San Diego the last couple of nights. Windshield scraping in Chula Vista and Imperial Beach. ---
**Author:** ![Pjen](https://avatars.discourse-cdn.com/v4/letter/p/3d9bf3/32.png) [@Pjen](https://boards.straightdope.com/u/Pjen)\ **Post date:** [December 12, 2013, 6:00pm UTC](https://boards.straightdope.com/t/homemade-windshield-deicer/384078/27 "2013-12-12T18:00:24Z")
> [@Leaffan](#): > > There is nothing that I’ve ever been made aware of that people spray on their windshields to prevent freezing. > > Anyway, straight antifreeze has a higher freezing temperature than a mixture of antifreeze and water. As listed in this [table](http://en.wikipedia.org/wiki/Ethylene_glycol#Antifreeze), a 70/30 mix of ethylene glycol and water has a lower freezing point than 100% EG. (-51C vs. -12C) In the UK at least there is a waxy spray that can be put on car glass that means that the Frost/ice slides off and does not stick- you just gently scrape it and it slides off. ---
**Author:** ![Kenm](https://avatars.discourse-cdn.com/v4/letter/k/bc79bd/32.png) [@Kenm](https://boards.straightdope.com/u/Kenm)\ **Post date:** [December 12, 2013, 6:10pm UTC](https://boards.straightdope.com/t/homemade-windshield-deicer/384078/28 "2013-12-12T18:10:03Z")
All those cures are old school. Use Finland’s tremendous breakthrough: [![Imgur](https://i.imgur.com/jptgSW6.jpeg "Finnish windshield washer fluid.") ](https://imgur.com/gallery/jptgSW6) ---
**Author:** ![purplehorseshoe](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/purplehorseshoe/32/2996_2.png) [@purplehorseshoe](https://boards.straightdope.com/u/purplehorseshoe)\ **Post date:** [December 12, 2013, 6:45pm UTC](https://boards.straightdope.com/t/homemade-windshield-deicer/384078/29 "2013-12-12T18:45:23Z")
> [@bob\_2](#): > > My father made an efficient de-icer. He took a metal biscuit tin, cut a hole in the side, and fitted a lamp holder. With a 40 watt bulb inside, and left in the car on frosty nights, it would stop the car from freezing up, even when it got down to -4 or 5C. I guess that in really cold places you might have to go up to a 60 watt bulb. > > I typed that and then realised that those bulbs are not available here any more. Maybe a halogen? Those of us who park outside (no garage) are 1) more likely to have ice/freeze problems, and 2) nowhere to plug in your dad’s invention. [Previous page](https://boards.straightdope.com/t/homemade-windshield-deicer/384078.md?page=1)