During the snowy winter weather here in Pittsburgh, we stored my wife’s Honda Accord in the garage for the winter. While the garage kept the car away from rock salt, icy roads, and deep snow, unfortunately it didn’t protect the car from water deposits. Wait, water deposits?
Well, yes. It turns out that our garage, made of concrete, will slowly soak water through it. Not very fast, but given a deep snowfall like Pittsburgh had, it’ll eventually work its way through, and very slowly drip. I didn’t think much of it, until several weeks had passed, and white, smooth spots had formed on the car. It turns out calcium leeches out of the concrete, and accumulates on whatever surface is below – in this case, the side of a Honda Accord. My wife’s Accord – her baby.
After swearing I’d fix it, no problem, right away, I grabbed the hose, the sponge, and the car soap, and gave it a wash. No change. A second wash, more vigorous. Then scrubbing hard. Now the wife was worried, so a quick trip to the auto shop to grab a clay cleaning kit. This promises to clean all manner of evil off cars – spray the lubricant on, scrub with clay, be the hero of the day. Even a friendly passing neighbor swears by it, telling me he used to work cleaning cars fresh off the train using clay. The result? Nothing.
Then I remember a useful bit of chemistry – calcium doesn’t dissolve in water very well, which means the scrubbing would get nowhere. However, calcium will dissolve quite easily in an acid, if I had one in hand. Like vinegar! Rushing into the house, grabbing the bottle of distilled vinegar, I triumphantly douse the spots in vinegar, and wait for it to work. And wait. And wait. Huh. Scrubbing doesn’t help much – some of the smaller spots come clean, but the big spots have no change. One last crazy thought enters my head.
Clay from the super-cleaning kit, a little bit of handiwork, and behold! This clay cavity holds a pool of vinegar on the spot. If you look closely, you can even see the bubbles from the calcium dissolving. A few minutes of waiting for the calcium to dissolve, a quick rinse with water (the vinegar might damage the car if left on the car,) and the calcium is gone. And I feel smart for the next few hours. And most importantly, the wife is happy.
