A common problem we see on windows is hard water staining. Our water in the mountains is quite hard and contains an abundance of minerals and other solids. This hard water can get on glass in a number of ways. The most common is sprinklers or irrigation that is being sprayed on the glass. One of the dirtiest is water dripping off a tile roof. Water splashing off of trees or other plants. You can even find it splashing up from the dog’s water bowl! Unfortunately, it is very easy to do damage with a simple spray of the garden hose or just washing the house and leaving the water to dry on the glass. 

So what is happening? These minerals remain after the water has dried. Worse yet, they start to build up very quickly. My house has several windows that have been stained with only 2-3 splashings of the hose. Think of the cave formation, the stalagmite. The drip, drip, drip of water over the years will result in quite a hard water stain. While I have yet to see a stalagmite growing out of a window, I have seen a deposit close to 1/8″ thick!

How do I get it off? Here is the problem, it is now part of the glass. They make all sorts of powders, pastes, creams, chemicals, and acids. I have tried many through the years and nothing works too well. Our procedure is a bit more environmentally friendly, and straight from a customer. We use full-strength vinegar with a bronze wool pad. This method does a nice job of shining up the glass. It will not completely remove the stain if the deposit is bad enough, no improvement will be revealed. A product called Crystal Clear 550 is commonly the go-to product. This stuff is a wicked strong acid. I will not use this product due to its extremely dangerous properties. Damage to paint, seals, siding, and trim, not to mention the health of all of us.

We will always try to inform the customer of hard water stains and their possible causes. Fix your splash and enjoy clean again!