Wipe: From cleaning cloth to solder joint

In everyday speech, to wipe is to rub something with a cloth, sponge or hand to clean or dry it. You wipe a table, wipe your hands, wipe rain from glass. The motion is the point: a single or repeated stroke that removes dirt, water or dust.

In plumbing, a wipe is a soldered joint made between two pieces of lead pipe. The plumber heats the junction until the lead and solder reach a plastic state, then uses a cloth rag, often swaddled in cotton or linen, to shape the molten metal into a smooth, tapered mass that bridges the gap and bonds the pipes together. The cloth protects the worker's hand and controls the solder as it cools and sets. The result is called a wiped joint.

Lead pipe joints soldered this way were standard in older plumbing systems and remain in use for specialist work, particularly in restoration and in some heritage installations. The technique demands skill: the solder must reach the right temperature, the cloth must be wet enough to prevent sticking but not so wet that it cools the joint too quickly, and the shaping motion must be steady and even to avoid weak spots or gaps.

The term draws directly from the tool and the action. Unlike modern push-fit or threaded joints, which rely on components or mechanisms to hold pipes together, a wiped joint depends on the plumber's physical motion, the rag that guides it, and timing. The same word that describes cleaning a surface describes sculpting metal: both are acts of controlled friction and hand motion applied to material.