It’s a rainy day here in South Dakota so I thought I would take this opportunity to write about something that I am getting lots of calls on lately. The dreaded water spot.
Its pretty straightforward what causes a water spot. A water spot is simply water that has been left on the surface that has minerals in it that when it dries it leaves behind the minerals which looks like a chalky residue.
The reason they can be stubborn to remove is because glass and paint is porous so when the minerals get left behind the minerals embed themselves into the pores. Also if the water is slightly acidic it will then create a small crater in the paint and glass that even if you remove the minerals the crater will leave a visible defect in either the paint or the glass.
If you have water spots on either your paint or glass the first thing you should do is try to remove them as soon as possible this will hopefully prevent them from etching into either surface. If you fail to catch the water spots until after they have dried no worries! There are a couple of things you can try. Get a spray bottle and fill it 50:50 with water (preferably purified) and vinegar. The acidity of the vinegar will help break up the minerals and hopefully get them removed.
If you get the chalky part of the water spot removed but it still leaves behind a defect your options become much more limited. On paint you may have to resort to polishing in order to get them removed while on glass you will have to have a detailer or glass shop attempt to remove them using stronger chemicals but if this does not work you will unfortunately just have to replace the glass.
So this sounds expensive and sounds really crappy right? Wouldn’t it just be better to prevent them in the first place? Hint: the answer is yes.
The best thing you can do is apply a sealant to your paint every 3 months to keep it protected and apply the same sealant to your glass. This will help with a couple of things. First off sealants will make the surface smoother and more hydrophobic so less water will be on the surface and it also creates a sacrificial barrier so if it does happen to etch it has to go through the sealant first then the clear coat of the paint. For glass there is also another added benefit of creating a Rain-X effect where your wipers will be more effective and water will also slide off when driving down the highway.
Since glass has much more limited options of removing water spots it also may be a good idea to think about applying a windshield coating so that you are protected for at least a year and the protection is much better than just a sealant. Read this article on windshield coatings to learn more about them.