[Nick_Thompson]

Can anybody remember the temperature differential before experiencing thermal shock?

Was it anything over 20ºC at the brush compared to ambient temperatures?

Nick

[Dave Willis]

That's the rumour. I think Nat suggested not going above 20 above ambient temps. Don't know if there are any scientific facts. Some guys get away with very hot temperatures on here but once you've cracked a customers window you'll soon back it down. Single pane glass you can actually here it creaking as you wash it - best avoided with hot.

[slap bash]

Thermal shock is around 65 degrees so dont go near its also the temp were poly urethane hoses become unstable and plastic fittings burst. I would say if its not more then 50 or less at the brush head you will be same and still have a good cleaning advantage over cold water cleaning.

[Dave Willis]

Are you talking centigrade 

[slap bash]

I would not use hot on older single paned glass as the thickness of od glass in uneven and the glass cutting methods left an edge which can easily crack. If a glass pane was polished in would n be near impossible to crack as a crack forms on a chipped cutting edge. That is why so many glass suppliers tape the cut edge for trans port.
Also interesting when glass is made in a liquid form its spread on  tin surface and the other side has contact air production a different charge the one been neg and the other positive.THis I was told by Pilkingtons Glass make hydrophobic and  hydrophilic. The one side anionic and the other cationic. The one spreads Rainex or any  Nano tech products it converts this charge to repel water, ware surfactants brake this charge to anionic. The read this up some time back while researching the subject.
Nano tech products were developed from the leaves of plants that naturally repel water.So that the water falls on to the root system.
Sorry if this boars you but it the geek in me.

[slap bash]

Dave I think if I remember right it centigrade, its half way to boliling.