Cleaning oil spill

[dstude]

This may be a little off the beaten path, but years ago I cleaned some oil spots off a concrete driveway using cat litter and it worked beautifully. It actually made the spot where it was spread cleaner than the surrounding area that hadn't been oily. The clean spot looked much like newly poured concrete.

I've recently tried it again, but this time on asphalt and it hasn't done much of anything. I've even tried three different cat litters, since many of them now have additives that weren't used decades ago, like being scented or non-clumping and not just the plain old clay litter of the past.

Is the problem that I haven't found the right cat litter or is it that I'm trying to use it on asphalt instead of concrete? Obviously, the asphalt is already oil-based and likely much more porous than concrete, so maybe it's never going to work. Does anyone have any good tips for cleaning oil or gas stains on asphalt?

Thanks.

[Skip Lackie]

You explained it when you said that both oil and asphalt are petroleum-based. Gasoline has molecules with the fewest carbon atoms (around 8 or so); oils are made up of molecules with more, while asphalt molecules are very long with hundreds of carbons. Because of that, oil or gasoline spilled on asphalt just softens it -- the various hydrocarbons are perfectly happy mixing it up and staying there together. Eventually, the lightest ones will evaporate or wash away, and the remainder will slowly harden up. But it won't happen quickly.

[Mrs K Corbin]

Dirt or sawdust.... However it's not going to rid you of the stain.

[swvalcon]

Cat litter is about the same make up as the floor dry they sell in a bag to suck up oil spills. When I was in the service in Germany we would clean the floors in the motor pool every Friday with diesel fuel and then wash it with laundry soap and water and squeegee it out the front door to the street drains. Made the cement look like it was brand new and all white. But try that today and you will end up in jail.

[altair]

There are asphalt finishes that you can cover the stains with, check with any reputable driveway repair company.

[Topper2011]

I understand concrete will also work to soak up oil spills.

[BRUCESTUDE]

I use commercial floor dry/ sweeping compound, and grind it in the asphalt with my boot. After it sets for a few days I sweep and the stain is gone!

[Jeffry Cassel]

I'll try the sweeping compound. I use diatomaceous earth that I get at the local mechanic's shop. Works great. $10 a bag that lasts a year.