Safety is as safety does...
In Part I we discussed the various things you need to have fun working on a car, well, other than Pam Anderson (or, if you prefer, Jonny Depp) in a coverall. These were a) a safe place to work, preferably a garage, and b) quality tools to get the job done. Now, we'll talk a little about working on a car safely.
An automobile is nearly always at least a full ton of steel, mounted on wheels, filled with enough gasoline to blow up a house and an electrical supply that can weld metal. Screw around with your girlfriend (or boyfriend) and they'll leave you. Screw around with your car and it'll kill you faster than a Palestinian "fashion belt."
So, there are a certain set of tools and procedures you must follow if you want to work on your car safely. These are basically non-negotiable if you don't want to be buried with it. If someone tries to get you to work on a car without this stuff, know you are doing so at your own, mortal, risk.
The first thing you need is actually part of your safe place to work: a hard, flat, level surface. An automobile is one of the first, best examples of mass versus weight. When your car is sitting on a level surface, all you're dealing with is its mass1, which neatly obeys Newton's laws of motion. In other words, if it's sitting still it'll tend to stay still, moving only when something acts on it. You'll be the only thing acting on it, so you'll be able to control it.
When you put a car on an incline, you're working with its mass and its weight. Weight is the force of gravity on an object2, and a car on an incline is basically a whole bunch of mass fighting to break free. This means that, instead of tinkering with a neutral lump, you're working around something that wants to move. Which means you have to sit there and figure out which ways it wants to move, and brace against them. Not impossible, but the consequences of screwing up can be, well, unpleasant.
The next things you'll need are a floor jack and a pair of jackstands. You may wonder, since cars come with jacks already, why you'd need a special one just to work on the car. Well, spare tire jacks are emergency-use devices, meant to help you impress chicks (or rescue helpless guys) and scrape knuckles. They're not designed to push cars into the air time and again, and don't lift the car very high into the air. As a car is lifted on a jack, it shifts around a bit. Spare tire jacks aren't designed to compensate for this, and so they'll lean over alarmingly as the car goes higher in the air. Floor jacks have none of these limitations. If you get one nice enough, it'll also lift the car a lot faster than any spare tire jack could.
Jackstands are simple (and therefore cheap), but one of the most critical "first-buys" you'll make. All they do is hold a car in the air. They are designed to never move, lean, crack, crumble, bend, or splinter. Rocks, cinder blocks, bricks, boards, and blocks have been used to hold a car in the air, sometimes even successfully, but only by stupid or very desperate people. At a typical cost of $50 for a pair of really nice ones (and half that for cheap ones), there's no reason not to have them.
These two items, jacks and stands, go together because they perform related, but distinct, jobs. The jack lifts the car into the air, and the stands hold it there. As you will find often in your adventures in automotive maintenance, these tools are very good at what they're designed to do, and they suck ass at anything else. If you use a screwdriver as a prybar and it snaps in two, you've usually just ruined a tool. If a car falls off a jack because you were too cheap to buy stands or too lazy to use them, at best you'll simply damage your vehicle. At worst you'll be dinner table conversation at the next coroner's convention.
This is important enough to deserve repeating: Never, ever, ever work under a car that isn't properly supported. A jack of any sort is not proper support. One of the saddest things I ever saw was an episode of "California Coroner"3 I caught on Discovery a few years back. Someone had called the police complaining of a stench coming from their neighbor's back yard. The police arrived to discover a very (as in 4-day) dead person half-squashed underneath a car. The moron had only used a bumper jack, and apparently he got a little careless and bumped it. The horrifying thing was it took a little while before he died. They could tell because he'd broken his fingernails off, desperately trying to lift a two ton Chrysler Imperial off his chest with his bare hands.
The third thing you should buy, or first if the stuff you need to do doesn't involve putting the car in the air, is a large fire extinguisher. The larger the better. Cars are filled with all sorts of nifty petroleum products, ironically the largest quantity of which is also the most flammable. None can be put out with a garden hose or a bucket of water. Once ignited, a car will quite merrily burn with a heat that can melt cast iron and definitely destroy an entire house. A fire extinguisher will ensure a random flame is a fun excuse to coat your garage with white powder, not a reason to call 911.
Stay alert when working on a car that's running. There are a lot of spinning parts in there, any one of which can lop off a careless finger or crush a misplaced hand. Assume that unless you're watching it, the hand you're moving is being placed straight into the path of the fan blades. This will ensure it always stays attached to your wrist. Put away the damned jewelry, which will get caught and torn up, probably cutting you up in the process. Make damned sure all long hair is kept under control, because getting that caught in a fan belt will tear your head off, which makes for a very messy cleanup.
The rest of it is just common sense. Stay calm, take your time, think about what you're doing. The really dangerous stuff usually has warning labels attached to it ("do not open when hot", "can explode if not properly ventilated", "keep hands and feet in ride at all times", etc.) Follow them religiously. Read the manual to learn the proper places to put a jack and stands, because you'll damage the car if you don't. If you don't have the manual ask someone, don't just take a guess.
Your car, your body, your friends and your family will thank you.
To be continued...