Trixology
Weather => Weather Hardware/Measurement => Topic started by: elagache on January 03, 2017, 12:12:49 AM
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Dear WeatherCat station caregivers,
Some of us have gotten into the habit of applying Rain-X (https://www.rainx.com/product/glass-water-repellents-cleaners/rainx-original-glass-treatment/#.WGrAlJISoX8) on our rain gauge collector cones to improve the accuracy of rain collection. One of our cars started to have windshield wiper chattering and it appears that Rain-X product build-up is at least partially to blame. Because of this, I looked into the chemistry of Rain-X and products intended to remove it.
I started by looking at the Rain-X product sold to remove Rain-X: Rain-X X-treme clean (https://www.rainx.com/product/glass-water-repellents-cleaners/rainx-xtreme-clean/#.WGrCBZISoX8). This is the only product that can be used to reliably remove Rain-X build-up. Here is a link to the SDS:
https://www.rainx.com/wp-content/uploads/2016/06/Rain-X-Xtreme-Clean.pdf (https://www.rainx.com/wp-content/uploads/2016/06/Rain-X-Xtreme-Clean.pdf)
I got a shock when I looked at the ingredients. Only three are listed: water, 2-Amino-2-Methylpropanol (a pH stabilizer,) and Aluminum Oxide (https://en.wikipedia.org/wiki/Aluminium_oxide). Aluminum Oxide is one of the hardest abrasives known to man. So much so that is used as an alternative to diamonds in some industrial applications:
https://en.wikipedia.org/wiki/Aluminium_oxide#Abrasive (https://en.wikipedia.org/wiki/Aluminium_oxide#Abrasive)
So that makes it clear there is exactly one way to remove Rain-X and that literally to grind it off. Even the manufacturer of Rain-X has no chemical process to remove it. That puts those of us using Rain-X on our collector cones in something of a difficult situation. Almost all collector cones are plastic and removing the Rain-X might well remove the top layers of plastic as well. It isn't clear that excessive Rain-X is a problem on collector cones like it is on windshields, but it is an unpleasant surprise.
At this point I turned to original Rain-X water repellent. Here is the SDS:
https://www.rainx.com/wp-content/uploads/2016/06/Rain-X-Original-Glass-Treatment.pdf (https://www.rainx.com/wp-content/uploads/2016/06/Rain-X-Original-Glass-Treatment.pdf)
I was in for an even nastier shock. The main ingredients listed in the SDS are: Ethanol, Acetone, Isopropyl Alcohol, and Sulfuric acid! Given those ingredients, I have no idea how it creates a water-repellent surface. Rain-X is considered a carcinogenic under OHSA and California?s prop-65 regulations. Now obviously these chemicals are in small enough concentration that they are unlikely to do any harm, still this is a nastier product than I had imagined it to be.
If you are using Rain-X on your automobiles, you might consider switching to Aquapel (http://www.aquapel.com/). While Aquapel is significantly more expensive, it appears to be a better choice for windshields on a number of grounds: easier to apply, lasts longer, and no problems of excessive build up. Unlike Rain-X, Aquapel not regulated as potentially carcinogenic, so that might be worth something in terms of peace of mind. Unfortunately, I don't think Aquapel will work on plastic, so it isn't an alternative for rain gauge collector cones.
So just some unexpected information on Rain-X. I think after reading this, you will (as I will) handle the stuff a bit more carefully from now on!
Edouard
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Thanks for sharing the results of your research Edouard.
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"Reading lists of ingredients can be dangerous to your health!" :)
Anxiously awaiting your report on Aquapel, along with a 50% discount coupon! :P
Chemistry is only one of the 5-credit hour classes I failed! :-[ I had always figured that Rain-X merely filled the spaces between the "glass molecules" with a type of very high density of "oil". However, I think I've only actually used Rain-X twice in my life. Perhaps that's been one of my healthier choices! :o
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Dear Blick, X-Air, and WeatherCat fans of slick . . . . .
"Reading lists of ingredients can be dangerous to your health!" :)
Well, I did feel a bit betrayed. I've been using Rain-X since the 1980s. It certainly seemed harmless enough!
I had always figured that Rain-X merely filled the spaces between the "glass molecules" with a type of very high density of "oil".
I had assumed Rain-X was a silicone-based product. Silicone has the same sort of water repellent properties.
Anxiously awaiting your report on Aquapel, along with a 50% discount coupon! :P
Well, since Aquapel doesn't have any applications for weather instruments, I don't know if there is that much interest. In a sentence or two I prefer it for cars that are garage kept. It does last the entire rainy season here in California.
What got me into this mess is that we have one car that is kept outside. Of course the windshield gets dirty all the time and I was looking for a way to clean and renew the water repelling shield on the surface. So I started using the Rain-X 2-in-1 cleaner and water repellent. Unfortunately, that product has clearly started to build up on the windshield and is making the wipers chatter even worse! So today's chemistry exploration was for products to remove Rain-X! Even that had some surprises in store.
There is at least one other rain repellent product out there from Griot's garage. When I have some time I'll try to look up its SDS and see if it is a more user-friendly product that could be used on our rain gauge collector cones.
Cheers, Edouard [cheers1]
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Edouard, any thoughts about a non-stick polymer like Sno-jet Spray?
I buy it by the gallon and have used it on my snow blower impeller and discharge chute for years with good results.
As I've written in these Davis collector cone coating threads in the past, I also use it on my weather station. No complaints, it beads up raindrops nicely and sure prevents snow from sticking to the cone and helps the rain collector heater keep up with snowfalls as long as they don't exceed a couple inches/hour.
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Dear Felix and WeatherCat armchair chemists,
Edouard, any thoughts about a non-stick polymer like Sno-jet Spray?
Well since you asked, you can look at the Safety Data Sheet for Sno-jet Spray. Home Depot's website has a copy:
http://www.homedepot.com/catalog/pdfImages/0e/0e56f590-ab4b-4e05-8250-457823414156.pdf (http://www.homedepot.com/catalog/pdfImages/0e/0e56f590-ab4b-4e05-8250-457823414156.pdf)
There is nothing in the composition that is carcinogenic, but clearly it is flammable in a way that demands caution. One of its active ingredients: "Petroleum distillates, hydrotreated light" is at least similar to Aquapel. The other ingredient - Naphtha - is a paint thinner. You definitely don't want to inhale the stuff, but it shouldn't be any more dangerous than a can of spray paint.
As I've written in these Davis collector cone coating threads in the past, I also use it on my weather station. No complaints, it beads up raindrops nicely and sure prevents snow from sticking to the cone and helps the rain collector heater keep up with snowfalls as long as they don't exceed a couple inches/hour.
I see that you can buy it in reasonably-sized spray cans, so it does look practical even for those of us who will never have to shovel snow. So yes indeed, if anyone is looking for a less nasty product to apply to your rain gauge collector cone, Sno-jet does look viable.
Cheers, Edouard
P.S. If you want to switch from Rain-X to something else, you'll need to remove the Rain-X to get the best results. According to the "car guy" world, mild kitchen cleaners like Bon Ami and Bar Keepers Friend should do the job.
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Dear WeatherCatters with slick collector cones, 8)
I finally have solved the problem of chattering wipers on the car that is left outside. It turned out that indeed there was a buildup of Rain-X and that does cause the wipers to encounter more fiction. While I was trying to figure out how to solve this problem, I found this comparison web article:
http://windshieldwiperguide.com/rain-repellent-reviews-a-windshield-glass-treatment-comparison/ (http://windshieldwiperguide.com/rain-repellent-reviews-a-windshield-glass-treatment-comparison/)
It turns out there are 3 different strategies to repel water. Rain-X as it turns out is depositing a some sort of a silicone layer. How its ingredients do this - I have no clue. Aquapel is a fluorinated petroleum distillate. The fluorine allows for the compound to bond to the silicates in the glass. That's why Aquapel lasts longer than Rain-X. What makes it good for windshields should make it not work on plastics like rain gauge collector cones - which are plastic.
There is a new technology that applies an nano-coating. This, in principle, bonds even closer with the silica particles in the windshield than flourinated compounds. However, as the author of the comparison noted, nobody has made a clear demonstration of this superiority.
Just to completely muddy the waters, I found pehaps the ultimate earth-friendly water repellent: Green Earth Technologies G-Clean Hydrophobic Rain Repellent (http://www.getg.com/G-CLEAN/rain_repellent.php)
Checking out the SDS it appears you could almost drink the stuff without hurting yourself:
http://www.getg.com/docs/MSDS/MSDS_G-Clean_Rain_Repellent.pdf (http://www.getg.com/docs/MSDS/MSDS_G-Clean_Rain_Repellent.pdf)
However, this stuff may also be intended for glass and not work on plastic collector cones.
I have one more tidbit related to all this. At least for windshields, the best cleaner is the original 1886 formula of Bon Ami:
http://www.bonami.com/index.php/products/powder_cleanser/#original-1886-formula-p (http://www.bonami.com/index.php/products/powder_cleanser/#original-1886-formula-p)
It has exactly two ingredients: tallow soap and feldspar (https://en.wikipedia.org/wiki/Feldspar). However, while feldspar is a mild abrasive for around the kitchen, it is a 6 on the Mohs scale of mineral hardness (https://en.wikipedia.org/wiki/Mohs_scale_of_mineral_hardness). So if you decide to remove Rain-X on your collector cone take care not to remove too much of the plastic along the way! Some plastics have an outer coating of UV protector which you most definitely do not want to remove!
Cheers, Edouard [cheers1]
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How much is a new collector cone with spikes from one of the several Davis discounters? If Snow-jet ever stops beading up water after a semi-annual application, I'm going to go that route. I've still got the old version (sans spikes) and the strainer in the bottom blew out in a hurricane a few years ago so I now have a homemade device.
OTOH, I've been considering boxing the entire unit up and sending it back to Davis for a refurbishment this summer. And I'm kind of thinking they might put the updated rain collector on it as part of the price of the refurbishment.
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You should be able to buy a replacement collector cone for the VP line for about US$
8024.50. :-[ I had Davis refurb my setup a couple of years ago and was very pleased with the outcome. They did not replace my cone as part of that service.
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You should be able to buy a replacement collector cone for the VP line for about US$80.
VP2 rain collector cone with spikes, latest debris screen, logo, gripping grooves for $24.50 (six in stock at this writing)
https://www.scaledinstruments.com/product/davis-7345-527-pro2-rain-collector-cone-kit-w-logo-grip-grooves-and-bird-spikes/
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Exactly what is the advantage of these chemical over plain ole carnauba wax?
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Dear X-Air and WeatherCat curious minds, . . . . . .
Exactly what is the advantage of these chemical over plain ole carnauba wax?
Well for a glass surface the answer is obvious. Have you ever tried to wax glass? ;D
More generally, the water beading action of these water repellent products is different from wax. Wax does repel water, but it does so by creating large beads of water. Rain-X and Aquapel cause the water beads to be much smaller. As a result you can see through them more easily and the actions of your wiper are more effective.
On a rain gauge collector cone the effect is to avoid water collecting in large beads on the cone and instead running down the cone to be counted by rain gauge buckets. It might be worth an additional 0.01" of accuracy particularly when the rainfall is very light.
You might not find that very worthwhile or you might . . . . . it all depends on how much time you have spent living in drought . . . . (http://www.canebas.org/WeatherCat/Forum_support_documents/Custom_emoticons/desert-smiley.gif)
Cheers, Edouard [cheers1]
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On a rain gauge collector cone the effect is to avoid water collecting in large beads on the cone and instead running down the cone to be counted by rain gauge buckets. It might be worth an additional 0.01" of accuracy particularly when the rainfall is very light.
You might not find that very worthwhile or you might . . . . . it all depends on how much time you have spent living in drought . . . .
To borrow the CoCoRaHS slogan, because every drop counts where I live, I apply Rain-X to my collector cone every year.
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Especially in winter with the heater on. Any snow flake that melts but doesn't roll down into the collector will evaporate from the heat. I've had very light snow for hours with no tips of the bucket if I don't keep the cone slick.
BTW, the very best way that I've found to get windscreens absolutely spotless is to use 0000 steel wool. First clean the windscreen normally, dry, then scrub with dry 0000 steel wool. It works amazingly well. Even gets those baked on water spots. Then I Rain-X the glass and wiper blades.
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[snow]
Ah... if your rain collector is level, plumb, the why worry about catching every drop? Why does anyone think that their rain cone needs that stuff in the first place.
My rain cone is just fine, it collects rain here and goes into the pan. Putting all sorts of crap in the pan, well you sometimes can gum up things, I'd just leave it as it came from the factory and if for some reason you feel the need for a new one,buy it. [cold]
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On a rain gauge collector cone the effect is to avoid water collecting in large beads on the cone and instead running down the cone to be counted by rain gauge buckets. It might be worth an additional 0.01" of accuracy particularly when the rainfall is very light.
You might not find that very worthwhile or you might ... it all depends on how much time you have spent living in drought ...
Thanks for a simple explanation for my simple mind. ;)
Not withstanding the possibility of a drought, if the climate warming process continues, I think the 0.01 accuracy is not worth the possible damage to the rain cone plastic. I've already applied a Rain-X layer and it appears its removal might be worse than another application. It does help on windshield, probably as much in not even having to use the wipers rather than running them on glass that still may have dry areas! :o Once above ~40mph, it is only during moderate to heavy rain that the wipers are needed. Of course, wipers aren't much use if, like me, you close your eyes when being scared... even when driving! lol(1)
I'll probably continue to rely on that force that keeps my feet on the ground now more than in the past, Gravity, to get those droplets into the drip buckets.
In other, slightly related news, I watched a PBS show last week about the Giant Sequoias. A local lay-scientist had designed a 'rain-collector' that was completely covered by a 'roof'. He was not trying to measure "rain" falling from clouds as he was actually measuring the moisture in 'special' clouds. These clouds were 'special' in the sense that they were actually at ground level, what we call "fog", a three-letter curse of many a pilot. His whole exercise was to measure how much water was available to trees in general and Sequoias in particular, even in a drought and when rain never reached their roots.
This collector appeared to be a series of dozens of vertically aligned, closely spaced (fish line) strings between an upper and lower arm. Three of these "fog combs" were arrayed around a central point where the lower "arms" met at a collector for all the drops that formed on the strings. The whole array was covered by what was basically an umbrella to keep out any falling precipitation.
The fog passing through the array condensed on the strings, fell to the bottom and then into the central collector. Gravity provided the vertical force, pressure differences provide the horizontal force. No batteries included. No mention of Rain-X, Aquapel or any other chemicals or even wax! [lol] They did, however, state that most of these giant trees were many decades older than any known Station Wagon!
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Notice the picture, the soil moisture station and all the water sitting on the frozen ground. It is frozen down to 2 feet right now, so we have puddles of frozen water everywhere making it difficult to go out to the station, much less into the yard to take the dog for a deturding. Hopefully Ed the Weather Guy is right and we get into the upper 40s this week and some of that ice will go.
Now, unless you have a rain barrel under your weather station to catch that 0.01 inches of water, introducing a substance that could and will mess up the rain collection system is not worth it to me personally.
Drought, I would put more stock into what my soil moisture sensors tell me of what the conditions of the soil is right now than grease my rain cone. I have a fully populated soil moisture/temperature station with leaf wetness sensor (s). I have only 1 out now and one on the shelf.
http://www.desmoinesweather.org/weather28/index.php?p=69&lang=en#data-area (http://www.desmoinesweather.org/weather28/index.php?p=69&lang=en#data-area)
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Why not put that station wagon out in the rain and let its windshield act as the collector. Could try with and without RainX. Of course you would need to measure and account for the area exposed skyward. Might have to removal the aerial, which could deflect a few of those precious drops, or maybe attract lightning. Here now the water is in a solid state and coming in horizontally. Alas, no rain collecting for a couple of months.
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Dear X-Air, Steve, Weatheraardvark, Irving, and WeatherCat forum visitors even on a "slow day." . . . . .
Especially in winter with the heater on. Any snow flake that melts but doesn't roll down into the collector will evaporate from the heat. I've had very light snow for hours with no tips of the bucket if I don't keep the cone slick.
I hadn't thought about the effect of evaporation. So the error could be considerably greater than my 0.01"
BTW, the very best way that I've found to get windscreens absolutely spotless is to use 0000 steel wool.
I'm sure that works but that's really hard medicine!
Then I Rain-X the glass and wiper blades.
With all I've learned I won't use Rain-X on a windshield anymore. I would like to learn more about these nanotechnology coatings, but for now I'll stick to Aquapel. However, some guys on the 65GS.com (http://www.65gs.com/board/) forum also use Rain-X on the wipers. At the moment I'm trying a dry Teflon lubricant, Rain-X clearly is a good silicone lubricant. I just worry of depositing the stuff back on the glass.
I've already applied a Rain-X layer and it appears its removal might be worse than another application.
Yes, I'm feeling that concern as well. I may stick to Rain-X on the collector cone because I can't imagine how a build up of Rain-X would do any harm. If I could figure out a reasonably safe way to remove Rain-X, I would like to try Felix's suggestion of Snow-Jet Non-Stick Spray (http://www.mo-deck.com/SNOW-JET-s/1820.htm).
Why not put that station wagon out in the rain and let its windshield act as the collector.
In the voice of Colonel Klink (from the Hogan's Heroes TV series if you are old enough to remember that)
. . . . Request Denied!!!!! . . . . .
Cheers, Edouard [cheers1]