The different types of Water Marks.

[Todd@RUPES]

A common question on this forum (and others) is how do I remove water marks from my paint.

Before we can prescribe a solution it is important to diagnose the problem.
Visible water marks generally fall into 2 categories, as illustrated below: Mark Spots and Water Etching.




Water Spots: Water spots are caused by evaporation of water droplets. Water is usually not pure and has some solid material that is left behind from the evaporation. Water spots are the solid remains left behind from water and they can adhere to the paint fairly strongly. Water spots should be considered contaminates or above surface paint defects.

Solution: If the water spots are fairly fresh then a wash with car soap and water can remove them. If they have adhered to the paint strongly or formed a bond they will be more difficult to remove. Wiping the paint with a mixture of distilled vinegar and water will help loosen and remove them. If this doesn`t work a clay bar, an All In One (cleaner/wax) or even a light machine polishing may be necessary.



Water Etching: Water etching is caused by a chemical reaction between the material in the water or the chemical make up of the water. Metal and calcium in the water spots, will over time, begin to eat away at the clear coat. This results in a crater, usually deeper along the outer rim, where the clear coat has been removed. Sometimes liquid chemicals in the water, such as high levels of acid (acid rain damage) can cause etching almost instantly.

The longer that water spots are allowed to sit on the paint and the more heat and sunlight they are exposed to, the greater the risk of them creating etching. Water etching is damage to the paint or a below surface defect.

Solution: The depth and severity of the water etching will ultimately effect the exact process that is used for removal. In the case of light water etching, a light machine polishing may fully remove them. With moderate to severe water etching the paint will likely need to be compounded or wetsanded to fully remove them. The best way to solve water etching is not allow it to take place to begin with.

[mjlinane]

Great info, Todd. This does come up often.

[Todd@RUPES]

Great info, Todd. This does come up often.

Thanks Mjlinane!

[Jrew359]

Thanks Todd. A timely post as I`m getting ready to tackle water marks on a 12-13 year old pickup.

[Todd@RUPES]

Thanks Todd. A timely post as I`m getting ready to tackle water marks on a 12-13 year old pickup.

Hopefully they are just water spots and not severe water etchings!

[TroyScherer]

Thanks for this info Todd.


I just got done trying the CG Water Spot remover on the hood of a black truck that I was hoping I could do quick easy fix on. No dice. Looks like I have a moderate to severe etching to deal with now....

[YNOT]

Great info...thanks Todd!!

[glfahlc1]

great info todd... i had a helluva time getting rid of my etchings.

[Todd@RUPES]

great info todd... i had a helluva time getting rid of my etchings.

Because water etching are so wide standard paint polishing doesn`t work too well. You end up polishing the low of the etching as well as the highs surrounding it. In a lot of cases wet sanding with a firm sanding block will allow you to remove the etching with the minimal lose in clear coat (or paint) thickness.