[nathankaye]

Interesting story, but impressive results

https://youtu.be/yvOMY361Uw8

[Slacky]

The inside of the car is equally as cold as the outside of the car.

This is not how it works with centrally heated houses in the west.

[nathankaye]

The inside of the car is equally as cold as the outside of the car.

This is not how it works with centrally heated houses in the west.

His story was how his friend defrosted his windscreen from the inside using a blow torch and still it didnt crack.

Ive cleaned windows when i used trad equipment and majority of the times its people's conservatory windows early morning that end up freezing as soon as you put the mop on to clean. As normally the central heating has been off all night and it takes some time to warm up inside conservatory.   

Im more worried when using hot water on hot sunny days than I am working cold/icy days

[paul alan]

I would think its the temperature difference that will have the most impact.

So on a freezing cold day when using hot the difference in temp if using 50 degree water on say -10 degree glass would be a big 60 degree. But on a hot day using hot the temp difference probably is not much.

When taking the temp on glass up by 60 degree in a second or two is when the glass will expand very quickly and will have the most potential for a crack.

[Jonny 87]

^^^^^ this.

Thermal shock is the reason for cracked glass.

I’ve heard of someone cracking a window on a very hot day with cold water. Not with hot.

Trust you Nathan to worry about the opposite scenario to everyone else.   

I Remember reading that thermal shock can happen with a sudden change of about 30 degrees.

On a hot day with hot water that’s probably not gonna happen, on a cold day though, with hot, it’s very possible.

[dazmond]

i cracked a little opener window on a cold day with hot water but it already had a little crack along the edge.ive also had windows creak when im cleaning them on a cold day.....

i dont think cleaning windows on a warm day with hot water increases the risk of cracked glass TBH....