How to Prevent and Remove Water Spots

Washing your car in the sunshine will bring with it the possibility of incurring stubborn water spots. Something as simple as a water spot can spoil the look of a freshly cleaned car, and potentially cause damage to the surface of the paint. We will talk about how you can prevent and remove water spots from your car. 

What are Water Spots?

We tend to think of water as H2O, two hydrogen atoms and one oxygen atom, but the water that comes out of our taps is far from pure H20. Over 60% of the UK has ‘hard water’ (Scaleguard UK, 2020).

Water hardness is determined by the mineral content of the water and varies by location. The south and south-east of the UK have the hardest water due to the lime and chalk geology of the area, while Northern Ireland and most of Scotland have softer water.

When a droplet of water dries on a car panel, the pure water is evaporated away, but the minerals are deposited on the surface of the paint. They form a hard, alkaline residue and if left for too long, they can etch into the paintwork.

How Can Water Spots Be Prevented?   

With water spots being caused by water drying on the car, the key to prevent them is not to let them dry. In the wintertime, this is not a problem, but in the summer months, it can be considerably more difficult.

The first consideration is time and weather. A cloudy day is ideal for washing a car, but this is not always possible. If you cannot find any shade to park your car in while washing, avoid washing during the hottest part of the day, usually between 11 am and 3 pm. Before and after this timeslot the panels on your car will be cooler, making water spots less likely.

If the only time you can wash your car is during the hottest part of the day, the best way to avoid water spots is to wash and dry one panel at a time.

Carry out a prewash on one side of the vehicle; check out our article on snow foam for more on this. Rinse down this side and carry out a safe contact wash. Using a pH neutral shampoo with no added waxes will reduce the chances of water spotting.

We like Adam’s Ultra Foam Shampoo, and this can also be used as a snow foam. After rinsing away the shampoo, use a microfibre drying towel to dry the car. Only dry areas that you have already washed, as using a towel on dirty areas may cause marring.

Repeat this process around the car, carefully drying any water spots as you go. Making sure any water drops are not left on the paint for more than a few minutes should ensure water spots are avoided completely.

If you still find water spots to be an issue, it might be worth considering investing in a water filtration system. DI Vessels can be filled with resin to filter out impurities in the water. This vessel can be connected in line with your garden hose before connecting to your pressure washer.

For this filter, the resin needs to be bought separately. You can also get a water impurities tester, to determine whether or not a change of resin is needed. 

YAKAMOZ LCD Digital TDS-3 Meter Temp PPM Tester Pen for Testing Water Quality
  • Usage: Help you drink the safe and pure water, protect your health. Check the performance of your water filter and the hardness of the water you drink…
  • Dual Range : Measures form 0-999ppm, with a resolution of 1ppm. From 1,000 to 9,990ppm, the resolution is 10ppm, indicated by drinking x 10image, +/-…
  • Features: The meter can lock the readings to help you read and record. Turns off meter after 10 minutes of non-use to save batteries

Having a filtered water system will allow you to rinse the car and let the water dry off naturally, without having to worry about water spots.

How to Remove Water Spots

If you do notice some water spots after washing, the first thing to try is to wash the affected areas. This will normally be sufficient to remove most water spots, but some that are more stubborn may need a different approach.

A product I often reach for when confronted with water spots is Koch Chemie FSE (Finish Spray Exterior).

This is a quick detailer that is specially formulated to remove limescale, such as is found in water spots. To use the product, apply a few sprays to the affected area. Using a clean microfibre towel, wipe the surface, rotating the cloth to buff to a shine.

This should be enough to remove any water spotting but any stubborn areas can be re-treated.

Koch Chemistry Design Finish Spray Exterior (FSE) – Quick Detailer with Chalk Paint Remover 1 L …
  • Koch Chemie Finish Spray Exterior is an all-round quick detailing spray with limescale remover, suitable for use on paintwork, glass and plastics….
  • Finish Spray Exterior cleans, maintains and preserves in one step leaving a slick and streak free, high gloss finish.
  • Built in limescale remover

Water spots can also be removed using a polish, as these have mild cleaning abrasives. Something like Autoglym Super Resin Polish should be sufficient to remove the water spot. Apply using a foam or microfibre applicator, leave to haze, and buff using a microfibre cloth. You can then add a layer of wax to protect the surface.

Water Spot Etching

If a water spot is not removed quickly, the minerals in the water can cause a small amount of etching into the clearcoat. These are usually only visible looking under direct light but are nonetheless annoying.

You should be able to remove these marks by hand, I would use Meguiar’s Ultimate Compound for this using a microfibre polishing pad.

Meguiar’s G17216 Ultimate Compound Color and Clarity Restorer, 15.2oz, Black
  • Remove Paint Defects: The ultimate product for removing oxidation, scratches, water spots, and blemishes without scratching
  • Cuts as fast as harsh abrasives restoring surface clarity without scratching or swirling
  • Save time: The clear coat safe formula dramatically reduces the time and effort to restore abused or neglected paint finishes

You could also use a machine polisher for faster results, a finishing polish such as Menzerna 3500 should be able to remove water etching.

Menzerna – Super Finish 3500 250ml
  • Orbital: Upper rotational speed range
  • By hand: Light pressure with circular motions
  • Cut: 3/10

When we add waxes or sealants to our paintwork, we like to see the water beading up on the surface. The disadvantage of this, of course, is that water spots are more likely to occur at those spots.

With that being said, having this form of protection is still preferable to having none. Having a layer of protection will mean the water is less likely to etch through into the clear coat and will make removing watermarks much easier.

I hope you enjoyed my guide on How to Prevent and Remove Water Spots. If you’d like to join the discussion on this, head over to the Prep My Car Facebook Group.


How do I remove water spots from my car?

Using a dedicated water spot remover such as Koch Chemie FSE will be the easiest way to remove water spots. You can also polish by hand to remove water spots.

Are water spots permanent?

Water spots are not permanent, but they may require extra effort to remove as washing alone may not be enough.

Will ceramic coating prevent water spots?

Ceramics are hydrophobic, so water is more likely to run off the surface. They can still get water spots; however, the coating allows for easier removal of these spots.

Will vinegar remove water spots?

Vinegar is an acid, so it will work well on the alkaline water spot, but it should not be used on paint. If your glass has stubborn water spots, white vinegar is a way you could remove these.

Can water spots damage car paint?

Yes, if not taken care of quickly, these can etch into the paintwork and will require machine polishing to fix.

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