Dear WeatherCat station caregivers,
Some of us have gotten into the habit of applying
Rain-X 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. 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.pdfI got a shock when I looked at the ingredients. Only three are listed: water, 2-Amino-2-Methylpropanol (a pH stabilizer,) and
Aluminum 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#AbrasiveSo 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.pdfI 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. 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