A propane torch can come in mighty handy for working on your car. I'm talking about the inexpensive hand-held variety, not the big oxy-acetylene units the pros use.
A 14-ounce cylinder of propane (enough for several hours of use) and a pencil burner head may run in the neighborhood of $10. A more versatile outfit, with a couple more burner heads and a soldering tip, may run about $17.
What can you do with one of these small propane torches?
Solder electrical wires (when a soldering iron or gun isn't handy), solder leaking radiators (when your soldering iron or gun isn't big enough), loosen rusted fasteners, free muffler and tailpipe connections and much more.
Using a torch is easy, and instructions usually come with it.
Basically the torch has three parts: the propane bottle, the burner and the burner head.
To use the torch, make sure the valve on the burner is fully closed, then screw the burner into the propane cylinder. The burner head is then screwed onto the burner, and you're ready to light the torch.
Turn the burner valve open a full turn, then hold the igniter (generally provided with the torch, but also available at hardware and auto-parts stores) half an inch in front of the burner head and squeeze it to make a spark.
If the torch doesn't light when you make the first spark, don't panic - it won't explode. Just keep making sparks until it lights.
When lighting the torch be sure that the burner head isn't close a wall or any other object you don't want burned. The flame shoots out several inches.
After the torch lights, adjust the flame. With a pencil burner head, you'll have two cones of flame.
The inner cone will be a darker blue than the outer one. Adjust the flame until the inner cone is 1' to 1 1/2' long - this is your most effective flame.
To shut the torch off, turn the valve clockwise until it stops. Twist it tightly shut.
When using the torch to loosen an object - say a rusted nut that's forzen tight - hold the torch so most of the flame causes the nut to expand, allowing you to turn it with a wrench. (Remove the flame from the nut, of course, before you place the wrench on the nut.)
Because heat causes metal to expand, these same techniques can be applied to various items on a car that must be separated - mufflers and tailpipes, for example.
When using the torch to separate stuck pipes, heat the outer pipe. If you heat the inner pipe you would be working against yourself - the inner pipe would expand against the outer one. Heating the outer pipe makes it expand, loosening its grip on the inner one.
Another use for the torch is soldering cracked radiator tanks. Clean the crack and the surrounding area with steel wool until the tank is shiny. Then apply paste flux (available in auto-parts stores and hardware stores) liberally to the crack and surrounding area. Then heat the metal around the crack until it becomes hot enough to melt the acid core solder which you hold against the crack.
Run the solder along the crack until it's filled, then withdraw the torch and solder. Let the soldered joint cool slightly, then wipe off any remaining flux with a wet sponge or rag.
To heat the crack you can use either a soldering tip or the flame from the pencil burner head.
When using the soldering head to solder, don't turn the flame up all the way. Adjust it so that the solid blue flames is just a little more than barely touching the back of the soldering tip.
Never use it near gasoline, or any other flammable liquids or objects.
Be careful where you point the flame. Even the area around the flame is hot enough to burn flesh.
Turn the valve tightly shut when not in use. As a further safety precaution, I unscrew the burner from the cylinder if I don't plan to use the torch again for a while.
Wait a few minutes before touching the burner and burner head after the torch has been turned off.