How to repair a leaking pipe
Instapatch can be wrapped around a pipe to seal cracks, pinholes and leaking joints on waste, drain, overflow and rainwater pipes. It works on copper, steel and plastic pipes, and hardens in 15 to 45 minutes under UV light.
- Never on gas pipes. In the UK, work on gas pipework must be done by a Gas Safe registered engineer.
- Not on mains or drinking water pipes. The datasheet doesn't give a pressure rating or approval for contact with drinking water, so use a plumber for those.
- Ask us first about pipes that carry hot water or get hot in use.
What you'll need
- Instapatch Standard patches. For pipes, you'll usually cut them into strips.
- UV Curing Primer and a brush. We recommend primer for pipe repairs.
- Scissors or a sharp knife
- Gloves and protective clothing
- Surface cleaner and clean cloths
- A UV lamp or torch for pipes indoors or in shade
Before you start
- Stop the flow and drain the pipe. The pipe must be dry before you start.
- Let a warm pipe cool down fully.
- The patch cures in air temperatures from -15°C to 70°C.
- Work somewhere well ventilated. Indoors, open windows and doors.
- The surface must be free from dust, grease, waxes and loose material.
- Only open the patch when you're ready to use it. It can start to cure within minutes in daylight.
Steps
Clean the pipe around the leak, remove any loose paint or rust, and let it dry.
Brush UV Curing Primer over the area and let it dry fully.
Cut the patch into a strip long enough to wrap around the pipe with an overlap. For a long crack or a joint, cut several strips to wrap in a spiral.
Peel the release film from one side and wrap the strip tightly around the pipe straight away. For a spiral, overlap each turn. Mould it to the pipe and apply firm pressure all over.
If you want to paint the repair, peel off the top film now for a matt finish. Leave it on for a gloss finish that can't be painted.
Cure it with daylight or a UV lamp or torch. Keep pressing the edges down until it hardens, so they don't lift.
Wait until the patch has hardened fully before you let anything run through the pipe again.
Cure timing for this surface
Outdoors, daylight cures the patch in 15 to 45 minutes, depending on how bright it is. Indoors, use a UV lamp or torch held close to the repair.
After the repair
Once it has hardened, the patch is waterproof and resistant to most acids and solvents. You can sand it or paint it.
Common questions
Yes. Instapatch Standard works on metal and plastic surfaces.
The datasheet doesn't give a pressure rating, so we don't recommend it for pipes carrying mains-pressure water.
Turn the heating off and let the pipe cool fully before you patch it. Ask us first about pipes that run hot in use.
Common mistakes to avoid
- Patching a pipe that's wet or still has water flowing
- Wrapping too loosely, or without overlapping the turns
- Running water through before the patch has fully hardened
- Using it on gas or mains water pipes
Safety
Wear gloves and protective clothing, and only use Instapatch in a well-ventilated area. It contains polyester compound and styrene, which can irritate the eyes, skin and lungs. If it gets in your eyes, rinse them straight away with plenty of water and get medical advice. If it gets on your skin, wash it off with soap and water.
Storing spare patches
Keep unused patches on end in their original wrapping, somewhere cool, dry, dark and frost free. If a patch is very cold, warm it before use.