How to Fix a Pinhole Leak in the Plumbing

Plumbers use a torch to install and repair copper supply lines.

Pinhole leaks often go undetected until their damage is already done, so consider yourself lucky if you're facing a fresh one. In general, there are three methods to fix a pinhole leak in plumbing: The difficult, yet most permanent, solution is to solder a repair coupling over the leak area. An easier way is to seal the pinhole leak with a specialized epoxy. The easiest way is to install a repair clamp over the leak. Learn how to perform all three pinhole leak repair methods and choose the one that suits your budget and skill level.

Things You'll Need

• Pipe cutter
• Bucket
• Rag
• Emery cloth
• Repair coupling
• Flux
• Flux brush
• Plumbing torch
• Solder
• Plumbing epoxy
• Putty knife
• Repair Clamp
• Nut drivers

Instructions

Soldering a Repair Coupling

1. Turn off the water supply to the pipe you are working on. Position the mouth of the pipe cutter over the pinhole leak. Tighten the pipe cutter over the pipe and twist the cutter to slice through the pipe's wall. Occasionally tighten the pipe cutter to cut deeper into the pipe's wall. Twist the pipe cutter until you sever the pipe.

2. Place a bucket beneath the cut and allow water to drain into the bucket. Once the water slows to a drip, dry the surface of the pipe with a rag.

3. Rub emery cloth on both cut ends of the pipe and both interior ends of the repair coupling to remove corrosion, grit and oils. Use a flux brush to apply a generous coating of flux onto the ends of the pipe and the interior of both sides of the fitting.

4. Gently pull one cut end of the pipe toward you. Slip the repair coupling fully onto the pipe. Push the pipe back to its original position and slide the repair coupling toward the adjacent pipe. Slide the repair coupling so that it is evenly positioned between the two pipes.

5. Light the plumbing torch. Hold the torch against the rear of one side of the coupling. Occasionally press the loose end of a roll of solder against the side of the pipe that you are heating. When the solder melts upon contact with the pipe, remove the torch and press the solder into the joint between the coupling and the pipe. Allow solder to flow into the joint until it squeezes out from the joint's rim. Wipe the fresh solder with a wet rag to remove excess.

6. Move the torch to the opposite side of the coupling. Heat the joint, apply solder and wipe the joint with a wet rag.

Epoxy

1. Shut off the water supply to the pipe that you are working on. Allow the pinhole leak to subside and piping system to fully drain. Dry the area surrounding the leak with a rag.

2. Mix the separate parts of your epoxy, if applicable.

3. Spread the epoxy over the pinhole leak with a putty knife. Immediately clean the putty knife. Allow the epoxy to cure according to the manufacturer's instructions.

Repair Clamp

1. Turn off the water to the pipe that you are working on and allow pipe to fully drain.

2. Place the repair clamp's rubber gasket over the pinhole leak. Open the repair clamp by spreading its hinge and position the clamp over the gasket. Compress the clamp's jaws over the gasket until the clamp's bolt holes join.

3. Thread the repair clamp's bolts through the bolt holes. Tighten the bolts with a nut driver. Turn on the water and check the clamp for leaks.

Tips & Warnings

• Instead of a putty knife, you can use a smooth, splinter-free scrap of wood to spread epoxy.

• Never use a plumbing torch near combustible materials. If you must, cover the combustible material with a fireproof cloth.

References

• Michigan State University Extension: Plumbing Repair Tools
• Copper Development Association: Copper Tube Handbook
• Utah State University: Basic Plumbing Skills