Water spots can be a nightmare to deal with if they are left unchecked for a long time. Water spots are also the Achilles Heel of ceramic coatings. Because of the water beading effect that ceramic coatings provide, water beads that stay on the car and are left to dry, leave mineral deposits that can sometimes etch into the coating itself and ruin it.
This guide will teach you what water spots are, what type of water spots can run into and how to deal with them. Regardless of whether you have a ceramic coating on your car or not.
If you leave water spots on your car without attending to them for too long. They will etch the clearcoat and get deeper into it. If you have a ceramic coating, you might run into the same issue.
So to avoid future headaches, make sure there are no water beads on the surface of your car. If you have a ceramic coating on the paint installed then you can even use something like a leafblower to easily remove all the water beads from the car's surface.
What are water spots on a car?
Unless we are talking about distilled water, all other water has minerals in them in some trace amount. Once the liquid dries, the minerals are what it left. If that process happens on the paint of your car, you are left with what we call water spots. What they really are is very small rocks that are stuck in the clear coat layer of the car's paint.
If you have a ceramic coating, those minerals get stuck on the coating itself. And while in most cases, water spots will not damage the coating itself, they still reduce its efficiency while they are left untreated.
What type of water spots are there?
There are two types of water spots that we have in the car detailing industry:
mild or soft water spots
stubborn or hard water spots
The mild water spots can usually be removed with little effort using water spot removing chemicals and a microfiber towel, while the stubborn ones are usually a headache to deal with and often require a more aggressive approach to remove.
The mineral amount in water is usually measured on a scale from Distilled Water which has no minerals in it and Hard Water which has a lot of minerals in it.
Depending on the area you live in, the plumbing, the water source, etc. Water that comes from an underground well will usually be heavier than the water that you use in your kitchen. But again, even that can be different based on where you live.
That is why you see more people with kidney stones in some places of the world and fewer in other parts. Kidney stones are basically the same thing - piled-up mineral deposits that came from the water that we drink.
How to remove water spots?
What we would suggest is using a 50-50 mix of water and white vinegar. If you ever had a calcium-based rock dipped in white vinegar you would see it start bubbling immediately. That is the acid from the vinegar starting to dissolve it.
This is basically what happens on the car's paint as well, just on a smaller scale of course. You want the vinegar diluted with water to reduce its pH value.
Using vinegar and water is an inexpensive way of dealing with water spots and we highly suggest you use that method instead of paying high dollars for products that are mostly the same thing. Vinegar does however have a strong odor, so keep that in mind when working indoors. It is not toxic, but a well-ventilated area goes a long way.
Mix the vinegar and water into a spray bottle, shake it well and then spray it on the area where you have water spots on. Leave it for about 30 seconds to 1 minute so that the acid can work its magic. After that rinse it with water and dry the area well. Just by using this, you should be able to deal with most of the water spots that you might encounter.
Those that you can't deal with this way are stubborn water spots that came from hard water or were simply left unchecked and they had time to build up.
WARNING: Do not try removing water spots on a hot day or in direct sunlight. Because the liquid that is used for the process will evaporate before it had a chance to dissolve those minerals. It will also likely leave stains if it evaporates before you had a chance to rinse it off with water.
How to deal with stubborn water spots?
You can try using the above method again. However, if the water spots are still there then you will need to get creative. Then you can either:
use a chemical specially designed for water spot removal
use 100 undiluted white vinegar
use a clay bar
use machine polishing
Using chemicals specially designed for water spot removal
This method will cost you some money. It is not that expensive, but if you are not careful, this can add up. What we use in our shop is Optimum 22394 MDA. MDA stands for Mineral Deposit Remover.
The product comes in a 1-gallon container. It is a brown-pinkish gel. And it is applied via a microfiber towel onto the contaminated area. You work the area using horizontal and vertical movements for about 30 seconds. Then rinse the gel off with water and dry the area with a clean and dry microfiber towel. The area should be water spot free after that.
You can repeat the process if the water spots are still visible.
If the water spots have penetrated into the clear coat, this method will not be effective.
Using 100% undiluted white vinegar to remove water spots
This is the cheaper and more aggressive method so take some caution.
Vinegar is quite acidic at a pH value of 2.5. Water for instance has a pH value of 7. That number can range from 6.5 to 8.5 depending on what water we are talking about, but still, the difference is huge.
This type of acid can damage the paint of your vehicle and is generally not recommended. If you have a ceramic coating the paint will be undamaged, but the ceramic coating, depending on the quality might lose some of its effectiveness.
With this method, you want to use latex gloves so the acid doesn't affect your skin. You might not see any damage after one use and might be thinking that you don't need gloves. But after a couple of the same uses, the damage would start piling up and you'd see and feel the difference. Always wear gloves when working with stronger chemicals.
The process is still the same. Spray it onto the hard water spots, wait for about 30 seconds to a minute and then proceed to rinse and dry. Hopefully, this took care of your problem.
Using a clay bar to remove water spots
If you haven't been able to remove the water spots by using the above methods, then you might be starting to see why water spots can be such a nuisance to deal with.
A ceramic coating will likely be removed by using a clay bar. Nevertheless, use lubrication that came with the product, or if it didn't, then use soapy water in a spray bottle. An automotive clay bar is an abrasive and it will cut more if proper lubrication is not applied.
If you do not have a ceramic coating and are using a clay bar on your car, make sure to use a paint measuring gauge to see if there is enough clear coat left on the car so you know it is safe to use without damaging the paint.
Almost all water spots will be removed by using this method. Reapply the ceramic coating after that. Follow our 8-step guide on how to apply a ceramic coating, check the clay baring step, and go from there.
If, however, you either do not have a clay bar or the water spots still persist. Then you probably have a headache and are to proceed with the final step.
Using machine polishing to remove water spots
This step is straightforward, but also very time-consuming. And can be expensive if you do not have the tools that are required. Check the tools in our recommended products section.
If you are new to car detailing and paint correction then you can also check our guide on how to perform paint correction on a car by machine polishing to get an idea of what you will need and how to do it.
After this, the water spots will be removed. The moral of this story is - always get rid of the water that has been left on your car as soon as possible before it dries out. Especially during the summer, because the days are hotter and the water evaporates much faster.
Any car is vulnerable when it comes to water spots, but those that have a ceramic coating on them are even more so because of the water beads that coating wasn't able to push off the surface of the car - especially on very large flat surfaces such as the hood or the roof. It all depends on the shape and the design of the car you're driving.
The best way of dealing with water spots is to prevent them from happening in the first place.