Facelift Indicators/ Condensation.

T-Cut · 13th July 2020, 12:19

The classic way of 'preventing' condensation fogging is to apply a film of a wetting agent on the glass (typically a windscreen in the old days). This doesn't prevent condensation, but it avoids the condensed moisture from forming discreet droplets. Microscopic droplets form the fog. So, you lower the surface tension of the water and droplets don't form. Instead you get a wet film that you can see through almost like normal. The original treatment was to cut a potato in half and rub the flesh on the glass. This deposits a film of starch, which does the wetting. Modern antifogs are simply better wetters. You can try it with a film of washing up liquid. They all work for a while, but continued condensation at draining washes off the film. The only fix is to stop the water getting in in the first place.

EDIT: Interestingly, they put a film of 'antifogging agent' on plastic wrappings for damp foodstuffs like meat. That keeps the plastic clear so you can see what you're buying.

TC

13th July 2020, 12:19	#21
T-Cut This is my second home Rover75 and Mreg Corsa. Join Date: Nov 2006 Location: Sumweer onat mote o'dust (Sagin) Posts: 21,753 Thanks: 341 Thanked 3,660 Times in 2,924 Posts	The classic way of 'preventing' condensation fogging is to apply a film of a wetting agent on the glass (typically a windscreen in the old days). This doesn't prevent condensation, but it avoids the condensed moisture from forming discreet droplets. Microscopic droplets form the fog. So, you lower the surface tension of the water and droplets don't form. Instead you get a wet film that you can see through almost like normal. The original treatment was to cut a potato in half and rub the flesh on the glass. This deposits a film of starch, which does the wetting. Modern antifogs are simply better wetters. You can try it with a film of washing up liquid. They all work for a while, but continued condensation at draining washes off the film. The only fix is to stop the water getting in in the first place. EDIT: Interestingly, they put a film of 'antifogging agent' on plastic wrappings for damp foodstuffs like meat. That keeps the plastic clear so you can see what you're buying. TC Last edited by T-Cut; 13th July 2020 at 12:24..