Water Spots by Magnification

In the world of rain, minerals, and cool-looking water beads, we always face the dreaded water spots on vehicles. Wishing for a spot-free finish where dirt just falls right off, and a brilliantly clean spot-free surface is left behind.

"Doesn’t that just sound grand!"

Well, with products created back in the early 1800’s such as waxes, we have strived to protect surfaces and keep them lasting. Whether that was hydrating a surface or just protecting it from other outside elements. We eventually furthered technology when sealants came about, extending the life of performance and helping fight against stronger chemicals that can damage surfaces on an automobile. Later moving forward to adopting and creating extremely durable and lasting coatings (Ceramic Coatings), that can withstand some of the harshest chemicals thrown at them, yet there has always been one complaint that has always plagued these surface protectants…

“Water Spots!"

"Dreaded Water Spots!”

“Why have these always been and continue to be the plague of a spotless surface?”

Well, shall we dive into what, why, and how these water spots keep leaving their mark behind?

What is a water spot?

• It is a mark or blemish left behind when water droplets dry on a surface, typically leaving behind mineral deposits or impurities.

Obviously, we know that a water spot comes from water, but why exactly? Why is it that when it rains or the sprinklers hit the vehicle, or droplets off a tree seem to always leave a water spot if we don't immediately dry it off…

Let's break down what exactly a water spot is. There are 3 types of water spots:

Type I: Mineral Deposits - Caused by hard water (rich in calcium, magnesium, etc.). When the water evaporates, it leaves behind white or chalky spots. These are the most common and typically sit on the surface.

Type II: Etching - Occurs when minerals or chemicals (like acid rain or sprinklers with fertilizer) etch into the clear coat, glass, or metal, creating more permanent damage that requires polishing or sanding to remove.

Type III: Bonded Contaminants - A combination of minerals and environmental fallout that bonds to the surface over time, sometimes embedding into the pores of coatings, paint, or glass. These often require chemical removal or claying.

When we see a droplet of water, many of us only think of H₂O (Water). We don't necessarily think of what else is in that said droplet of water.

Minerals in Water

“Inside a single droplet of water, one could find: Dissolved minerals, Microorganisms, Organic Matter, Gases, Suspended Solids, and other Contaminants such as pesticides or heavy metals.”

A droplet of water or a water bead is so much more than most imagine. We think this simple little water bead will just run off the surface, or “it’ll dry on its own.” Well, that is true in many cases, yet what will it leave behind?

Now this was titled "Water Spots by Magnification", right? So let's get to the point. When we have a hydrophobic surface or a surface of little tension, a water droplet will create a bead vs sit more flat on the panel. This is where we study the contact angle of the droplet.

Contact angle

The higher the degree of the angle, the less contact the water droplet or bead has with the surface it sits on. When this occurs, the bead acts as a "magnifying glass." The rounder the bead, the more focused the sunlight is on a tight point beneath the droplet.

What can happen:

Light through Water

• On a sunny day, this magnification can increase the local surface temperature beneath the droplet dramatically (like using a magnifying glass to burn paper).

  
  

• If water remains on a panel (especially on dark paint or soft clear coat), it can cause:

  • Heat stress to the clear coat

  • Micro-etching

  • Permanent ring marks or water spots

With a lower contact angle, the magnification is reduced, meaning that the bead will not get as hot, will take longer to evaporate away, and essentially allows more opportunity for one to dry off the vehicle. That sounds better, right? Well, the downside is that you have more water and more minerals sitting on the panel than you did with a bead (droplet) with a higher contact angle.

Feature	Low Contact Angle	High Contact Angle (e.g., 110°)
Water retention	High	Low
Risk of water spots	Higher	Lower
Magnification (sunlight)	Potential etching if stagnant	Reduced risk due to quicker runoff
Coating protection	Less effective	More effective

But wait!

If a high contact angle bead (droplet) gets hotter faster than a flatter (lower angle bead), then how is that better? Overall, the panel will have fewer minerals sitting directly on the surface and a higher chance of running off the panel. This allows the panel to stay cleaner and have less of a mineral film buildup.

A common oversight is that a hydrophilic surface (water-loving) is better as it allows water to sheet from the surface. A major downside is that this allows water to cling to a larger surface, and in turn leave behind more minerals than if it were to be hydrophobic and bead water. (yeah, I know I just repeated myself)

Visually, you may see water spots more so on a coated hydrophobic surface when in reality, a hydrophilic surface may have more minerals and or film build left on the surface, however, visually more uniform, which in turn makes one think it is cleaner due to the lack of random spots.

Feature	Hydrophilic	Hydrophobic
Water behavior	Water spreads out, clings to the surface	Water beads up and rolls off quickly
Drying time	Slower – water sheets take longer to evaporate	Faster – beads slide off or evaporate more quickly
Risk of water spots	Higher – because water remains and evaporates	Lower – less water stays behind to leave minerals
Magnification effect	Less severe (spread water lenses light less)	More severe (beads act like magnifying lenses)
Self-cleaning ability	Poorer – water clings, carrying dirt across surface	Better – rolling beads lift and carry dirt off
Aesthetics (Gloss & Beading)	Less glossy appearance, no beading	Glossy, slick appearance with attractive water beads
Contaminant buildup	More prone – water carries and deposits contaminants	Less prone – beads run off, taking dirt with them
Common on	Glass, uncoated paint, anti-fog coatings	Coated paint, ceramic/graphene-coated surfaces

Techniques to Remove Water Spots

After assessing water spots, the next critical step is removal. Here are effective techniques you can employ.

Manual Removal with Clay Bar

Using a clay bar is an effective technique for removing surface water spots.

1. Wash the vehicle thoroughly to eliminate dirt and debris.

   
   

2. Mist the surface with a clay lubricant to reduce friction.

   
   

3. Gently rub the clay bar over affected areas until the spots disappear.

   
   

4. Wipe with a microfiber towel and inspect for any remaining blemishes.

   
   

This method is particularly effective for surface spots and leaves the surface smooth, ready for further care.

Chemical Cleaners

For stubborn etched water spots, chemical solutions can provide relief.

1. Choose the right cleaner, such as a specific water spot remover.

   
   

2. Apply according to manufacturer instructions, usually involving spraying the solution onto the stains.

   
   

3. Allow the cleaner to dwell for the specified time before gently buffing with a microfiber towel.

   
   

4. Repeat if needed for tough spots.

   
   

Finishing Touch: Protective Coatings

Once you've removed water spots, consider applying a protective coating.

• Ceramic Coatings: These can offer long-lasting protection against environmental contaminants, including water spots and UV damage.

  
  

• Paint Protection Film (PPF): This serves as a physical barrier against scratches and etching caused by water spots.

  
  

Preventive Measures to Avoid Water Spots

Preventing water spots is as vital as removal. Here are a few practical tips to reduce the risk:

Rinse Water Sources

• Use Distilled Water: Opting for distilled water when washing your vehicle can prevent mineral deposits from hard water.

  
  

• Drying Techniques: Dry your vehicle immediately with a microfiber towel after washing to stop water from leaving deposits.

  
  

Regular Maintenance

• Frequent Washing: Establishing a consistent washing routine minimizes mineral exposure on the surface.

  
  

• Pre-Waxing: Applying a quality wax or sealant can protect the surface and help repel water.

  
  

Environmental Adjustments

• Park in Shade: Keeping your vehicle shaded during washing can slow evaporation.

  
  

• Weather Awareness: If rain is imminent, cover your vehicle or postpone washing.

  
  

The Importance of Detailers in Water Spot Resolution

Detailers play a crucial role in identifying and fixing water spots. Employing thorough inspection techniques allows detailers to serve customers better and maintain vehicle value.

Detailers with a solid understanding of water spots are invaluable. They not only provide solutions but also teach clients preventive measures, fostering a more informed car care community. Blah Blah Blah...

But wait!

I didn't mention the dreaded Ghost Water Spots!

Also known as Phantom spots, these water spots we all "knew" we got rid of. We treated the surfaces with a water spot remover, clayed, polished, and the finish was flawless. I checked in under high-intensity spotlights, pulled it out into the direct sunlight, took pictures of the flawless work, and posted it to social media for this awesome before-and-after!

And then...

I get a call from the client...

"What did you do to my car?" "My car is covered in water spots again!"

Your heart skips a beat, you feel crushed, thinking to yourself, what could have possibly gone wrong?

But what did go wrong?

Those pesky water spots we thought we got rid of had buried themselves deep into the clear coat. When we polished the surface, we were essentially just skimming the surface and removing the top layer. But as we "Pro Detailers" know, paint expands and contracts. Paint is porous and acts much like a sponge.

"But paint is hard to the touch! It's not a sponge!"

Oh, but paint is always moving with temperature. When those minerals sat on the surface for days, in the sun, then the shade, and back into the sun, the minerals sat there getting deeper, and deeper, and...... Deeper!

In this case, it may take multiple polishing cycles to fully remove them, or sanding, keeping in mind we only have so much paint/clear coat to work with. In extreme cases, we may not be able to fully remove the ghost water spot as the damage is too severe.

Severity	Treatment
Mild	Light polish or finishing polish
Moderate	Compound with machine polishing
Severe	Wet sanding or clear coat correction (professional)

Final Thoughts

Water spots may appear minor, but a solid understanding and effective techniques can help manage and prevent them.  Proactive maintenance goes a long way in preventing etching, ghosting, and surface degradation.

Keep your vehicle away from sprinkler systems, and don't park under a tree if you know it is going to rain. Don't rinse off your vehicle and let it air dry. You are just asking for water spots. Take the time and dry off a "clean" car. Use a waterless or rinseless wash to help reduce contamination and keep your vehicle looking clean and "Spotless."

Detailing is about more than just cleaning; it's about enhancing and preserving a vehicle's beauty and lifespan. Let's tackle water spots proactively and help our clients achieve that spotless shine!

Tony Kiger - EYE OF THE KIGER