If you’ve ever used wax to seal an envelope, you understand the basic premise of soldering. Take a material (in this case, solder; pronounced sod-der) and heat it so that it melts onto items, such as two wires you have twisted together to make a physical connection. When the solder cools, you have a seal or joint that makes an electrical connection between the items. Soldering requires that you get your hands on a few basic items:

Soldering iron: See an example of one in Figure 3-1.

Tips: Large tips can be chisel-shaped and about 1⁄8" wide; small tips can have a cone shape with a radius at the tip of only 1⁄64". Most soldering irons don’t specify the tip sizes that are supplied with the iron. For most electronics work, we suggest you just find one described as a fine tip at a electronics supplier. If you’re ordering a replacement tip, a 3⁄64" cone shape is a good size for general use. If you’re soldering circuit boards, you might try a 1⁄64" cone-shaped tip. Figure 3-1 shows a soldering iron with a collection of different tip sizes and shapes.

Stand: You need a device to hold the soldering iron. To ensure that it doesn’t tip over with a hot soldering iron in it, make sure that the stand’s base is heavy enough or that you can clamp it to your worktable.

Damp sponge: You will use this constantly to clean the soldering tip between soldering jobs.

Solder wick: This piece of flat, woven copper wire — also called a solder braid — soaks up solder when you need to rework a connection and need to remove a dab or two from a joint. Some folks use a desoldering pump to suck up solder, but we find that a wick is easier to use.

Solder: Solder is a material that when heated and then cooled, holds wires and other metallic connectors together. The standard type used for electronics is referred to as 60/40 rosin core solder, which is 60 percent tin and 40 percent lead with flux at its core. This flux in the solder helps to clean the items you’re putting together as you solder. We suggest you use a 0.032" diameter solder, which is small enough to help you keep the solder where you want it to go.

Tip cleaner paste: This paste is an option for keeping your soldering iron tip neat. Although using a damp sponge (see its earlier bullet) will keep the tip clean for a while, a good cleaning with tip cleaner paste now and then is a good idea.

You will use drills for all kinds of tasks, from attaching wheels to the body of an electronically controlled kart to drilling holes in boxes to fit switches, lights, and much more. Drills commonly come in 3⁄8" or 1⁄2" chuck sizes. (The chuck is the opening in the drill where you insert the drill bit.) This measurement tells you how large of a drill bit (its diameter) will fit in the chuck. For the projects in this book, a  3⁄8" drill is just fine. Drills come in cordless versions as well as the type you plug into a wall outlet. We prefer cordless drills such as the one you can see in Figure 3-2, along with an assortment of drill bits.