can beading be bad?

[bcwang]

Normally we associate water beading as a sign of good wax protection on the paint surface. But does anyone wonder if those tall tight beads can be worse for your finish with the sun shining on it getting magnified? I know that beads of water can be used as a magnifying glass for the surface underneath, and magnifying sunlight into an intense spot on the paint finish doesn`t sound too desirable.



I notice my car is usually the only wet one after sitting a few hours in the sun because of the beads of water that seem to take longer to evaporate than the sheets of water other people have. But that means the sun was shining on these magnifying beads for quite a long time.

[imported_Intel486]

I can`t remember but I saw something not too long ago that proved water drops sitting on the surface can cause the sun to damage the surface underneath. I forgot what I saw though. Hopefully it`ll come to me.



I wouldn`t worry about it though. Your vehicle doesn`t sit there that long with water drops on it and even if they are there and the sun is showing full, then they should evaporate quickly.

[bcwang]

But the problem with my car is it doesn`t evaporate quickly. I`ve had the sun out for so long that every single car in the parking lot was completely dry, the ground was dry, the dirt by the bushes was dry, but my car still had beads of water on it that would not dry up. Guess it was a cool day but with strong sunlight. This happens often when it rains in the morning, and my car sits on the parking lot all day long until I come out around 7pm, and it`s still wet.

[Brad B]

FWIW, I spoke to a 3M rep recently who said they are working on wax formulas to sheet the water faster for the reasons you state, yet still give good protection. But the problems they are having is that the results have been tradeoffs in gloss.



I have spoken to Sal Zaino and I know he takes pride in the tight, tall droplets produced by his product coverage and uses them as a means of measure.



I tend to fall in the latter camp.



If your car gets water damage then that`s the decision maker for you, I suppose. But I have never found it to be a problem on my Z covered cars, for instance. (silver and red)

[imported_Aurora40]

Have you ever tried to focus light through a drop? If you just put a drop of water on paper, it will slightly magnify the lettering. If you want that effect to be greater, you need to have the drop of water up off the surface. Imagine laying a magnifying glass on something. Sure, it focuses the light into a slightly smaller area, but not a beam or anything. In order to get a beam, you have to have more distance between the glass and the object. Since the water droplets don`t sit inches above the paint, but rather right on it, I suspect the focusing of light is fairly minimal. Just my thoughts...

[pies]

Originally posted by Aurora40

Have you ever tried to focus light through a drop? If you just put a drop of water on paper, it will slightly magnify the lettering. If you want that effect to be greater, you need to have the drop of water up off the surface. Imagine laying a magnifying glass on something. Sure, it focuses the light into a slightly smaller area, but not a beam or anything. In order to get a beam, you have to have more distance between the glass and the object. Since the water droplets don`t sit inches above the paint, but rather right on it, I suspect the focusing of light is fairly minimal. Just my thoughts...

must agree :xyxthumbs

[ntoddalbert]

Aurora40, good approach



I will sleep better now

[imported_method]

Hi everyone, proud to finally make my first post on the Autopia forums! I first learned about it in the detailing section of bimmer forums.com and its great to be here.



Anyway, the idea of water droplets magnifying light is a ligitimate one, and there does not need to be any distance between the water and the car.



I once worked at a plant store in my freshman year of college (in Texas) and we had to stick the hose at the very base of the plant to water it. The reason was to avoid getting water droplets on the leaves of the plant because they would magnify the light and actually burn holes into the leaf and make it look ugly (unsaleable). I saw this for myself.



Sorry to tell you the bad news, but please note this doesn`t say much for whether it ruins your paint, as car paint with a wax over it is different from a leaf. Thus I can`t say if it is too harmful for your paint, but I do know that droplets magnify light!

[imported_jgv]

My opinion about this is: If the surface under the bead gets warm enough it`ll dry the water before any damage can occur to the paint.

[bcwang]

My dad had a red integra which had circular faded white spots on the hood, which looks the size and shape of water beads. So either the spots were white from additional fading caused by intensified light in those areas from water droplets, or the water droplets had some chemicals in them that weakened wax in the area to allow more fading to occur. This kept occuring even though we tried to keep the panel waxed frequently. Finally had to do a repaint because the whole hood was turning chalky and white in very uneven patterns.

[imported_memnuts]

The reason I hate allowing any of my ultra detailed cars be rained on ( reason for a beater) is because of spotting created by beading. The residue remaining after the evaporation of the bead contains acidic elements that are now concentrated. If possible I will at least wash down ASAP after rain to avoid this spotting ( erosion) of the protective coat. That is why I prefer a bead-to-sheeting protectant over a tight beading product. The only product that met this desire was BFII. I have also noted that un-topped EX has this tendency. Fortunately, we live in a low acid rain area and this is not a problem. When I grew up in the Northeast :scared.

Sheeting would be the preferred method of protectant activity, rain, acids, alkaly, dirt, runnings off vehicle, but beading is engrained into our psyche as sign of protection and looks sooo

[Tim Lingor]

Maybe I can help on this one a little. It is not so much the drop of rain that is causing the damage but rather what is in the rain. Sulfur Dioxide (Sulphur Dioxide) emissions that go into the air and mix with the water vapor, forming a powerful acid: Sulfuric acid. (Sulphuric Acid)

(SO2 + H2O = H2SO4)

Better known as acid rain!!



When it rains, the drops of rain containing acid will sit on your car. In that state, they are not that bad, not good either. BUT, when the sun evaporates the water, it increases the concentration of the acid within the remaining water. Add to that the magnifying effect of the concave water drop---BIG TROUBLE!! Now you get etching!



THere is nothing you can do about it unless you get a car cover. So to me, I will make sure I have a good sealant and wax on the paint and that is all I can do about it.

:nixweiss

[Taxlady]

I know about the brown spots on leaves from water beads. But, plants are alive and are damaged at much lower temperatures than automotive paint.

[square]

I`m not sure how much magnification of the sun is going on. Any optics experts out there?



A water bead is a plano convex lens. If you know its focal length, then you can figure out how far befind the lens where the suns rays would be focused. Since the lens sits on the surface of the paint, the lens would have to have an extremely short focal length, less then the thickness of paint.



I believe a large water bead, 1/4 - 1/3 inch diameter, will have a focal length of 5mm, or about 1/4 inch. So, if you had a water bead on a piece of glass, the suns rays woud be focused about 1/4 inch behind the back of the water bead. So I don`t think the suns rays would ever be focused on the paint. And if there is no focus, then no addiitonal heat will build.



Water drops evaporating and concentrating acids, that seems possible.



Lou

[shaf]

Originally posted by method

Hi everyone, proud to finally make my first post on the Autopia forums! I first learned about it in the detailing section of bimmer forums.com and its great to be here.

Welcome to Autopia Method! :welcome



I`m wondering if we`re more worried about this than we should be. Like Taxlady says, plants are more fragile than auto paint and it probably wouldn`t take too much light concentration to kill their cells via heat and/or UV. I mean, it`s not like you hear a lot about how people`s waxed cars are developing strange cases of pinpoint damage after it rains. :nixweiss



I also agree with what`s been said about acid rain concentrating. Not just acid rain either, but even just regular pollution and contamination that gets soaked up by clouds and rain. I honestly really do think "water spot etching" is caused by having water dry up in one spot, causing the chemicals dissolved in it to become super-concentrated. This is the same reason why stuff like wheel cleaners shouldn`t be allowed to dry out. It can probably be avoided simply by hosing the car off with tap water too (unless you have hard water of course ).



Just my $0.02.