By John Goodman, Top Gloss Detail, Reno, Nevada, United States
Water spots are one of the most common problems I see on customers’ cars in Northern Nevada. Sometimes a customer will introduce water spots while washing their vehicle. They don’t realize water coming out of their hose may be hard water that contains lots of minerals. If they don’t dry their car quickly enough, water will leave behind mineral deposits. Since it is so dry here, water evaporates rapidly, leaving behind spots that have a thin white outline where the water droplet was sitting on the paint or glass. That white outline left behind is actually dried minerals, mostly calcium and magnesium.
Another way hard water spots can get on your car is from irrigation sprinklers. When parked outdoors your car may be hit with irrigation water from a sprinkler while you’re dining or shopping or visiting someone. Irrigation water is loaded with minerals, and these water spots can seriously damage your paint unless they are treated quickly.
You can also get water spots just from driving on a warm sunny day. If you drive through a brief thunderstorm and park outside, the water droplets will quickly evaporate and leave behind mineral deposits.
How can you fix water spot damage?
A vehicle owner can minimize damage from water spots by taking quick action. They should bring their car to a professional auto detailer as soon as possible, preferably within a couple of days. In the meantime, apply distilled white vinegar to a clean cloth and lay it over the affected area and let it sit for several minutes. Then wash off the vinegar thoroughly with car wash shampoo or rinseless wash. If the water spots are on or near the hood, the heat from the engine combined with the heat from the sun will cause water spots to etch into the clear coat very quickly. The heat enlarges the microscopic pores in the paint. This allows the minerals to travel deeper into the clear coat. This process is repeated every time your paint gets hot, from the engine or the sun. Day after day the minerals are etching deeper into the paint until they cannot be easily removed.
If this happens to you, bring your vehicle to a qualified professional. Use the Find a Detailer search tool to locate a member of the International Detailing Association (IDA) near you. The proper treatment will involve application of acidic water spot removers of different strengths. The acidic solution will break down and dissolve minerals in the paint. This may not completely remove stubborn water spots, and they may need additional treatment with machine polishing.
Even if you know someone who is handy with a polisher or buffer, if they are not a qualified detailing professional, do not let them attempt this unless they have experience with hard water spots. Using a machine polisher before properly pre-treating the water marks will only drive them deeper into the paint!
About the Author: John Goodman is the owner of Top Gloss Detail in Reno, NV. We provide a full range of auto detailing services, including Paint Correction, Exterior Detailing, Interior Detailing, Ceramic Coatings, Wheel Detailing, Glass Polishing, and Water Spot Removal.