Flexible wire saw blades can be used to cut pipe in difficult to access locations. For example when the pipe is next to a wall or there is inadequate access to use a hacksaw or Sawzall. However there are some special characteristics of the wire blade you must take into account.
Wire saw blades tend to jam in the middle of the pipe where the blade bridges across the hollow center if the blade is looped around the pipe. This is because at this point the blade is being forced to make a sharp 90-degree bend where it enters the pipe. To avoid this you must cut more side to side with your hands
separated as much as possible. This will keep the blade straighter and prevent it from jamming in the cut. You will also find that using your whole body (especially legs) to move from side to side rather than just pulling back and forth with your arms is less fatiguing.
Getting the cut started in pipes with a smooth surface such as PVC and ABS also requires some technique. The blade will tend to slide up and down the pipe without cutting into it. Placing a piece of masking or duct tape on the backside of the pipe easily solves this. It will resist the sliding long enough for the blade to cut into the pipe. Once started there is no problem. If you are unable to place a piece of tape (or any other method of stopping the blade from sliding such as a hose clamp) you can get it to start by holding the blade at an angle opposite the slide direction and getting in one good stroke with a strong pull. This requires
some practice to achieve however. A single stroke with out sliding is sufficient to start the blade in most materials.