Got it a spray of the gunk on my rear caliper brake yesterday. Stuffs gunky as hell. Anyone have a quick tip for getting it off? (It's too soft and gooey to even scrape away.)

Thanks.

WD-40 (or Goo Gone) and a toothbrush.

You should start with mineral spirits (paint thinner). Road tar is a hydrocarbon as is mineral spirits. Use gloves and put some mineral spirits on a rag and work on small areas at a time. Do it outside as well. For gloves go to a hardware store and get nitrile gloves (should be green or blue). Depending on how much tar you got on the bike, it will be messy so don't wear your "Sunday Go to Meetin'" clothes.

If mineral spirits doesn't work, try kerosene or diesel fuel but be extra careful with both. You might look at an automotive store for tar remover but be careful with it since I don't know what it might do to bicycle paint and parts. Don't use gasoline because the flammability is just too high for it to be safe. Alcohol, acetone, methyl ethyl ketone, lemon juice or a whole host of water based remedies won't work because tar is tough stuff that is not soluble in water based solvents.

Really? that's all? wow, alright, thanks.

I have used Kerosene successfully to remove road tar.

While everything you say is correct--in that it will work--for the implied "spray," I would still start off with the more common, more benign household things like WD or Goo Gone, saving the big guns (that require keeping a Haz-mat team on alert) for if/when they're really needed.

YMMV....

Careful using WD-40. First, it's a spray and will get all over everything. If you must spray it on a rag and work with that. Second, WD-40 has lubricants in it that will stick to the frame and attract dirt and grit. If you use it make sure you chase it with something like mineral spirits to get the residual off. Third, if you have to use mineral spirits to remove the residual, you might as well start with mineral spirits and see if it works.

Go simple first, then use more agressive measures if necessary.

I use Simple Green and it seems to get most crud off, including grease. Sometimes it has to "sit for a while" though. Easy to clean up, too. Just hose it off.

Do you use a degreasing hand cleanser? In the UK most workshops and garages use Swarfega. It dissolves the oily stuff then forms an emulsion with water. It works well against grease, tar or any other oily substance on any surface.
I've used it to remove black oily stains that my shoes have transferred to the carpet.

Just to clarify, this is tar that was used to patch a hole in the street and hadn't dried. I avoided it with the front wheel, but the rear got some gunk on it and sprayed a couple of thick strands onto the caliper brake. Doesn't look like any got on the frame or even in any moving parts; pure luck there. First thing I think I'll try is Simple Green, since that's all I have here, but I'll move up from there.

From a chemistry standpoint, WD-40 and Goo Gone are far more complex and hazardous mixtures than mineral spirits. WD-40 contains several aromatic hydrocarbons and longer chain aliphatic hydrocarbons as well as lubricants that are more persistent in the environment than mineral spirits. Mineral spirits are low molecular weight hydrocarbons like hexane, heptane and octane which are relatively begign and more volatile. Volatility increases their flammability but they also don't leave residue on the frame.

As for the Haz-mat remark, the tar is far more hazardous than anything else. Asphalt is actually a very hazardous material that leaches hydrocarbons, and nasty ones at that, into the environment all the time. We really shouldn't be spreading this junk around all over the planet but...

Okay, tree hugging mode off.

Be particularly careful around braking surfaces with whatever you use. Don't get anything on the tires or the wheels. It would be best if you would remove the wheels before you start. Any solvent will play hell on your tires and anything like WD-40 will play hell with your braking system. At the least stuff like WD-40 on your brake pads will make them squeal like a stuck pig. At the worst you won't be able to stop! I'd even be careful around the brakes with mineral spirits or Simple Green.

Most of the hand cleaners I've seen have abrasives in them. That wouldn't be a good thing to use on polished parts or on painted parts. If you could find some that didn't have abrasives, it would probably work quite well.

Yes, mineral spirits aren't too dangerous and should do the job, just use with adequate ventillation. And I would avoid getting it on rubber or plastics too. Doesn't every cyclist have some mineral spirits around for the occasional chain soak?

Stay away from WD-40 and other lubricants. You don't want that stuff on brake pads and braking surfaces.

You can get tar remover at any auto parts store. It's designed to be used on painted surfaces.

methyl ethyl ketone (MEK) is one of those nasty organic solvents. It's a good thing it really doesn't have any use for tar removal. For example:

Methyl Ethyl Ketone can affect you when breathed in and by passing through your skin.
* Methyl Ethyl Ketone should be handled as a teratogen--with extreme caution. [Note: _teratogen_ is a medical "code word" meaning it causes birth defects]
* Exposure can cause dizziness, headache, blurred vision, and cause you to pass out. Repeated exposures, along with other solvents, can damage the nervous system.
* The liquid can severely burn the eyes and may irritate the skin. Repeated exposure can cause drying and cracking of the skin. The vapor can irritate the eyes, nose, mouth, and throat.
* Methyl Ethyl Ketone is a FLAMMABLE LIQUID

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?

Oh, please, hug away!

.

How about brake cleaner? You can get it at auto stores. It's a spray, dissolves stuff, and evaporates leaving no residue...

MEK = methyl ethyl ketone

It will be labeled that way. Mineral Spirits is a different solvent and will be labelled "Mineral Spirits." Kerosene will be labelled "Kerosene."

MEK (a.k.a. methyl ethyl ketone) has no use as a bike solvent.

As far as tar on your bike, I've use small amounts of charcoal lighter fluid (OUTSIDE). You can buy products formulated to remove the sticky goo left behind by some merchandise price labels. They probably contain solvents you want to use in limited quantities, like xylene.

Wear nitrile gloves like all the people in those Park Tool "how-to" pictures do.

You don't want MEK (= methyl ethyl ketone) or brillo pads (will ruin your finish). Buy a small container of mineral spirits or similar (kerosene, perhaps lighter fluid). There is a rule of thumb in chemistry, "like dissolves like", and since tar contains a mixture of non-polar hydrocarbon molecules you will need a similarly non-polar solvent, none of which have very nice safety warning labels. As far as these things go, mineral spirits aren't too bad, and they aren't 'corrosive'; just keep the top securely closed and you can keep it next to your worms....

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.

Brake cleaner might work but it is far more hazardous than other solvents. Brake cleaner contains chlorinated hydrocarbons like those use in dry cleaning. They may be linked to cancers and are difficult to dispose of. Start with simple stuff and work up to more complex mixtures if necessary.

I said the very same thing but in lots more words I have to learn this brevity thing.