Well, second greatest enemy. The greatest enemy against the beauty of our automotive finishes are the extreme amounts of UV exposure from the sun that we get, but more on that in another article. Water spots, on the other hand, have immediate and long lasting effects on our car finishes.
St. George receives some of the "hardest" water in the country. What this means is that each droplet of water that comes from our wells has a lot more sediment and minerals in it than in most other areas. Because of this, when a sprinkler or other source of well-water hits your car and then dries on it, all of those sediments and minerals are left behind in a small ring where each drop sat.
There are two stages of water spotting. Initially, the minerals and sediments are sitting on top of your clear coat, and can still be removed by means of washing, chemical break down (wiping with white vinegar), or light abrasion such as using a clay bar or light polish. The second stage of water spotting is a lot more serious. This happens when the UV rays from the sun (remember that #1 enemy we listed earlier) reacts with the minerals and sediments to actually "etch" or eat down into your clear coat
When this happens, deep compound and polishing (also called Paint Correction) is needed to remedy the issue. How much is needed? That depends on how deep the etching is. Another factor that comes into effect that many consumers and detailers may not be aware of is that some automotive clear coats have "memory". I know that sounds weird. I've only seen it once in my experience, but it does exist.
This is an issue where we bring a car inside the shop, and proceed through our usual process for Paint Correction (decontamination wash, clay bar, spot free rinse, dry, IPA wipe, inspect, compound, polish, reseal, etc), and afterwards have a panel that is perfect looking and free from the previous water spot etching. Rather proud of ourselves we take the car outside and prepare it for delivery to our customer. After sitting in the sun for an hour, the water spots ACTUALLY CAME BACK. When you see it for your first time you can't believe it. You just spent hours correcting the panel, and now all your hard work went down the drain, and not a drop of water has touched the panel since you finished! What happens is that after heat cycling (getting hot, then cold, then hot again, etc), the clear coat actually develops a "memory" and even though it was polished and perfected inside the shop, upon returning to the sun light, the memory of that clear coat returns and it moves into small pits where the water spots were.
The only way to rectify this is to perform a Paint Correction while the panel of the vehicle is hot enough for it to re-form to its memory. This in of itself presents a LOT of challenges to the detailer. I've only had this happen to us once thus far, and it was on a vehicle that had be repainted. That's one of many reasons why it's always important to inform your detailer if you know of any panels on your vehicle that have been repainted. You may not know of a repaint in your vehicle's history, but your bid for water spot correction may have more than doubled upon us finding these results.
OH NO I JUST WALKED OUT TO MY CAR AND IT'S COVERED IN SPRINKLER WATER SPOTS, WHAT DO I DO!??!!?
Great question. Firstly, time and sunlight is our enemy here. Wash your car as soon as you're able to. Depending on how long the water spots have been on there, the damage may already have been done, but regardless, we want to minimize further damage as much as possible. Wash the car ASAP.
After that, unless your vehicle wears a Paint Coating or has some REALLY good wax or sealant on there, it's most likely that some water spotting remains. At this point you can try wiping down the area lightly with a clean microfiber towel and some white vinegar. Vinegar is very acidic on the pH scale and will help break down the sediments that are bonded to the clear coat. If this works, be sure to reapply whatever wax or sealant you like in that area.
If this still doesn't work, you can try to use some clay lube and a clay bar to remove the sediment. Clay is designed to glide over your clear coat's surface and pick up particles and contaminants as it does so. If this works, again, you'll want to apply some wax and sealant in that area.
If spotting remains in your paint work at this point, you'll want to bring your vehicle in for a Paint Correction. There is a chance that some of that sediment and minerals are still remaining down in the etched areas of each spot so you'll want to have the issue corrected sooner than later. Paint Correction can get expensive pretty quickly because it's very labor intensive. You'll want to do this now though, as allowing the issue to remain in your clear coat won't just leave your clear coat dull and unattractive, but the open pores will lead to oxidation, delamination and further issues down the line.
And that's why I've named Water Spots as Southern Utah's (2nd) worst enemy against our vehicle's finish. The 1st enemy against your paint? We'll save that for another article ;)