Originally Posted by peripatetic
Thanks, but maybe you could fill me in on another 'key word': MEK. What is this in layman's terms? Would this be the aforementioned mineral spirits, or kerosene or what? The more info youse give, the more confused I'm becoming. I went into the hardware store today, looked at the mineral spirits, and decided that I really didn't want to bring home a whole bottle of the stuff just for one tar removal job, only to be stuck with a nasty and corrosive chemical under the kitchen sink and right next to my precious worm composting bin. I left with a couple of brillo pads at the suggestion of the store clerk; for the record, he said mineral spirits wouldn't work, and he pointed me to some kind of gunk remover, but that looked nasty, too. So which one am I gonna use, guys?
Education mode.
Scientists have this nasty habit of taking in abbreviations. Normal, nongeeky, cool people pick up on these abbreviations and start using them and things start to get confused.
MEK is one of a class of compounds called ketones. The actual name, based on a international cabal of chemists call IUPAC, says that ketones shouldn't be called ketones at all but should be called by the alkane parent name ending in -one. So, properly named according to this secret cabal, methyl ethyl ketone should be named 2-butanone. This tells every other member of the secret society of chemists
what this stuff really is.
Confused? Don't feel bad, it takes a couple of years of college level study to understand how chemicals are named. There are well over 5 million organic compounds in existence and without some rules on how to name them, we chemists would have called them all Bob followed by a number. But Bob450,252 doesn't tells us much about the molecule so we came up with this naming system.
Now what you really need to know is that ketones, like MEK and acetone, and alcohols, like methanol and ethanol and isopropyl alcohol, are good for dissolving some things especially things that are slightly soluble in water. Mineral spirits, also know as paint thinner, kerosene and diesel oil are good at dissolving things that aren't soluble in water. Tar and grease fall into the latter category.
Things like Goo Gone and tar removers are mixtures of solvents that work on a broad range of materials and will do the job but are more expensive. I'd start with mineral spirits since it is cheap and most households have it around. If you don't get the Goo Gone or a commercial tar remover. I'd stay away from the brillo pads since all they would do is spread the tar around (think Cat in the Hat) and scratch the surfaces of what you are trying to clean.
Finally, corrosive and caustic are terms used for acids and bases, respectively and shouldn't be applied to solvents. Corrosives eat metals (and flesh), which is a chemical reaction, while solvents dissolve substances but don't change their physical characteristics. In other words, if you remove the solvent you still would have the tar. If you try to get metal back from a corrosive, you have a pile of rust.
If you are still with me at this point (and most people won't be) the main point is to try simple stuff first, mineral spirits and elbow grease or simple green (since you have that) and elbow grease. If those don't work, try something more aggressive. Experiment, within safe limits, you never know what you might learn.