Never use hot water to de-ice anything - car windscreens, paths, whatever. The heat evaporates rapidly and you just leave water to freeze again into black ice. So what you describe as 'amazing' is actually a direct consequence of using hot water. And obviously on glass, even toughened glass, it's a really bad idea.

As the last poster said, turn the engine on and use the blowers to warm the glass while you scrape or use a de-icing spray on the outside. If the glass is still cold when you start driving, it could fog up really quickly on the inside and re-freeze on the outside. I once sprayed the windscreen just after starting to drive and it froze solid almost instantly. I had to pull over as I couldn't see. Very dangerous, and I'll never do that again!

This post was last modified: 11-02-2012 05:44 PM by rshdunlop.