Do you ever wonder how minerals can be good for the body but bad for windows and laundry? As a nurse, I’m fascinated by the fact that calcium and magnesium keep our bones strong and our hearts beating, but they can leave hard-to-clean deposits on glass and fabric.

Save money by making your own Super Glass Cleaner using inexpensive ingredients.

When Carolyn commented on our “Make Your Own Outdoor Cleaner” post, she said she’d found a cheap substitute for a good window cleaner. “Our water is hard, hard, hard,” she said. “Solution: diluted distilled white vinegar. Works like a charm.”

Vinegar does work great at dissolving minerals in hard water. A fun experiment you can try with your kids is soaking a raw egg in vinegar and watching the shell dissolve before your eyes. Or try the same thing with a chicken bone. Calcium doesn’t stand a chance in acidic vinegar.

Here’s a glass-cleaning recipe I concocted teaming the power of vinegar with rubbing alcohol. Later I’ll explain the science behind why it works — if you care to stick around for the lesson.

Recipe for the Savage Sisters’ Super Glass Cleaner

Ingredients:
1 cup water (plain old tap water, even if it’s hard)
1 cup isopropyl alcohol (a.k.a. rubbing alcohol)
1 teaspoon white vinegar (acetic acid)

Directions:
Pour all the ingredients into a spray bottle, give it a shake, and start squirting. This simple solution pries even dried salt-water spray off the windows of our old Bayliner when we return from checking crab pots. When you first spray the solution on a window, it will seem really wet, but it wipes off beautifully, taking all the dirt and gunk with it.

Depending on the mineral content and pH of the water, as well as how grimy your windows are, you may need to tweak the recipe by adding more white vinegar. I’ve been known to add up to 1 cup of additional vinegar.

In an emergency or when there’s a lot of bird poop or other yucky stuff on the glass, I use paper towels for wiping off the solution. But for everyday cleaning, I prefer to use sheet rags that can be laundered and used over and over again.

There you have it, the combination of vinegar and rubbing alcohol gives the Savage Sisters’ Super Glass Cleaner a one-two punch against the gremlins of grime.

SAFETY ALERT!
Never use a vinegar solution to clean marble. Since marble is nothing more than a dense form of calcium carbonate, the vinegar will etch the surface of your expensive countertop.

BONUS: Jennifer explains the science behind vinegar-based cleaners.
Diana and I always want to know the reason why behind everything, so in case any of our readers are curious too, here is the science behind the phenomenon of “hard” water.

Meet the culprits — calcium and magnesium. Thanks to all the science classes I took in nursing school, I know that minerals, especially calcium and magnesium, are what make water hard.

How do the minerals get into the water? Pure water is often called a universal solvent because it picks up impurities so easily. When raindrops fall through the air, they combine with the hydrogen sulfide that results from coal burning — which makes sulfuric acid — and the rain also combines with carbon dioxide — which makes a weak carbonic acid — and the end result of all this combining is acid rain. As acid rain flows through the ground, it dissolves tiny bits of minerals from rocks such as limestone (calcium carbonate) and dolomite (magnesium carbonate).

Why is it more difficult to clean with hard water? Blame it on the soluble calcium and magnesium bits (ions) floating around in the water. These ions chemically bond with soap (sodium stearate) to form scum (insoluble calcium and magnesium stearate) instead of forming lather. If you keep adding soap, eventually all the calcium and magnesium bits will be bound up. Once this happens, soap will suds easily and can work as an effective cleaner.

Besides containing environmental pollutants, most commercial glass cleaners leave a very fine wax residue. The alcohol in our recipe helps cut through the oily, waxy stuff, and the vinegar (acetic acid) breaks down the minerals, which slightly etches the glass clean and returns hard water to a more neutral pH. So the water, the universal solvent, cleans better.

How to use this information at your next social gathering. The next time you want to quickly end a conversation at some party, try mentioning a few of these facts. As soon as the other person’s eyes glaze over, you’ll be free to return to the buffet table for more spinach dip — which just happens to be high in calcium and magnesium.

m

Written by Fiercely Frugal Savage Sister Jennifer

© 2009, The Savage Sisters