Copper is most commonly used in water pipe and electrical wire. When newly produced, it has a bright gold color. Over time it fades to more of a golden-brown.
Copper that has been exposed to moisture for a long time will develop a green layer of corrosion. Some buildings over the years have used copper roofing and subsequently show a distinctive green color on top. Sometime gutters and downspouts are copper as well.
If you replace water lines in your home or business, they will usually be copper. Extremely old buildings sometimes have pipe that was manufactured from steel, which is grey or rust colored (unless painted over) and will stick to a magnet. In recent years, the use of plastic pipe or flexible tubing has become more widespread, replacing copper in that application.
When recycling copper plumbing, pay attention to whether there are fittings or valves on the end. These will normally be made from some other metal alloy, like brass or steel. The color will be different from the rest of the pipe, so it’s easy to notice. Removing these in advance will save you from weight or price deductions at the recycling center.
When it comes to grading, used water pipe is #2 Copper. New pieces that do not have solder on them will go for #1 Copper, which is worth more money.
The walls of your house or business have copper wiring going from room to room, connecting the electrical outlets to the fuse box. Another copper cable connects your fuse box to the local utility’s pole or line buried in the ground.
By simply removing the wires from any outlets or boxes they are attached to, you have upgraded them to where you will receive the best price, unless you want to go to all the trouble to hand-strip the plastic insulation off the copper wire.
Important note: It is illegal to burn the coating off of copper wire. The Missouri Department of Natural Resources imposes severe fines on people caught burning illegally.
Hand-stripped copper that is 16 gauge in thickness or heavier, and still looks bright, is graded as Bare Bright Copper. If it has been exposed to air long enough to acquire a dull finish, it is #1 Copper. If the wire is less than 16 gauge in thickness, it is graded as #2 Copper, regardless of whether it is bright or dull.
If you run into those rare pieces of copper gutter, downspout, or roofing you will have what we call Sheet Copper. As long as there are no attachments made from some other metal, or a heavy layer of tar, it is ready to sell as is.