Tips for Cutting and Connecting Pipes
Pro plumbers share their favorite tips and tricks for cutting and connecting pipe.
Should You Use Caulk or Putty?
Despite the name, lots of plumbers never use plumber’s putty. It damages some types of plastic and stains surfaces such as natural stone. Plus, it tends to dry out, crack and allow leaks. Silicone caulk is a safer, longer-lasting sealant in most areas where you might use plumber’s putty.
Thread sealant (aka “pipe dope”) is formulated to seal threads. But it’s great for almost any connection, even if the threads don’t form the seal. Use it on compression fittings, ground fittings and rubber seals. Because it’s slippery, it allows connections to slide together correctly for a good seal. And, if you use a type that doesn’t harden, disassembly and repair will be easier years later. Some types of dope harm plastic parts, so be sure to check the label.
How to Cut Pipe with a String
It’s almost as fast as a saw and fits into tight spots where saws won’t. To give the string a starting point, cut a shallow notch with a file or hacksaw blade. Then simply pull the string back and forth to slice through PVC or ABS pipe.
Milwaukee’s 2470-21 M12 Cordless PVC Shear is so cool that you may want one even if you don’t cut pipe for a living. It will make clean, burr-free cuts through plastic pipes all day long. Watching this tool in action is almost mesmerizing, and to be honest, a little frightening. We highly suggest knowing where your fingers are at all times when using it.
The tool can handle up to a 2-in. Schedule 40 plastic pipe. Milwaukee recommends it for PVC and PEX pipes, but we also used it so slice through a bunch of ABS, water lines and irrigation pipes. We even hacked through a tree branch. Older and more brittle pipes tend to crack instead of slice, so eye protection is always a good idea.
A Quick Cutter
Plumbers spend a lot of time cutting copper pipe, so it’s not surprising that one of our pro’s favorite tools is a tubing cutter, but not just any tubing cutter. The one he likes doesn’t require any adjusting—you just slip it over the copper tube and spin it to cut.
You can buy the Kopex tubing cutter shown here on Amazon. You’ll find similar tubing cutters at some home centers and hardware stores. Keep in mind that you’ll have to buy a separate cutter for each size tubing.