Rain Observation

[galaxy]

Didn't know where else to post this one since it's not really a question.

whenever it rains and I'm at work or something with the car or truck just sitting in the parking lot, I always go to leave for the day and my vehicles will still be covered in beading water while every other car in the parking lot will be completely dry. You guys ever have that effect? I'm sure it's related to surface tension and all that on a well waxed surface. Pretty cool.

[Mantilgh]

Yep, I think it the surface tension. The water will just lay flat on neglected cars and kind of slowly sheet it off. That thin flat layer will evaporate much quicker than your big fat beads.

Beads can leave spots though because of the dust has settled on the car, but they are usually easy to clean off. If it's hard water, like from a sprinkler, you can get hard water spots... The downside of beading. :(

[FUNX650]

whenever it rains and I'm at work or
something with the car or truck just
sitting in the parking lot,

I always go to leave for the day and
my vehicles will still be covered in
beading water while every other car
in the parking lot will be completely dry.

I'm sure it's related to surface tension
and all that on a well waxed surface.
•Whenever "water systems" interact with
other surfaces---[even to the extent of
exhibiting surface tension]---(1)cohesion,
(2)adhesion, and (3)intermolecular bond-
ing forces are factors that should be taken
under consideration.

[Come to think about it:
I'm pretty sure that (4)hydrophobicity
(a force that pushes/repels something
away from something else) is also a factor.]

-When (1)cohesion is more of a factor:
water forms spherical droplets ("beading").
-When (2)adhesion is more of a factor:
we get water "sheeting".
-I consider water to be a nearly perfect
(3)hydrogen-bonded-system.
-It appears that well Waxed surfaces/Water
usually (4)repel each other...at least more
so than: Un-waxed surfaces/Water.



Bob

[Paul A.]

Yes, but isn't it a blast to see those beads run and fly off during the drive.

[galaxy]

It's so gratifying it almost makes me want it to rain on my clean car...almost ;)