Copper tubing is often used to carry water to and away from a hot water heater. As a result of age or damage, a copper tube may develop a pinhole. Pinholes are small holes that form in a pipe and allow water to either drip or spray. You can repair a pinhole in copper and prevent damage from leaking water with epoxy putty and pipe wrap.
Locate the pinhole leak by observing water dripping or spraying from the copper tubing. Turn off the water supply before beginning work.
Prepare the area around the pinhole by roughing the copper with a metal file. Lightly rough the area around the pinhole so that the epoxy and tape adhere more easily.
Put on gloves, pinch off a dime-size piece of putty and roll it between the palms of both hands. Knead and warm the epoxy until it is pliable, and place it on the pinhole. Push the epoxy into place on the copper tube so it overlaps the pinhole.
Place a roll of pipe wrap in a container with cold water. Soak the wrap for 30 seconds, remove it, squeeze out the water and soak it again. Squeeze excess water from the tape a second time.
Wrap the tape around the pipe beginning below the pinhole. Wrap the tape over the leak and then beyond to provide a secure seal.
Massage the tape by rubbing it with both hands in the direction that it was applied. Continue massaging until the tape begins to harden and set. As a rule of thumb, this takes two to three minutes.