Repairing or Soldering Copper Pipe
REPAIRING COPPER PIPE
Burst or damaged sections of copper pipe are best cut out and replaced with new (but see Trade Tip below). A frost damaged pipe is likely to have expanded well beyond the actual burst, making it difficult to fit new joints, so don’t be tempted to skimp on materials — cut out at least 300mm (12").
Where the pipe is rigidly fixed between two points it may be difficult to insert a new section with conventional couplings. There are two ways to overcome this problem.
♦ Use special slip couplings. These have no internal stops, allowing them to be slipped on to the old pipe ends and then slid back again over the joint once the new section is in position. Slip couplings are available in both compression and pre-soldered form.
♦ Fit a flexible connector, which can be bent by hand to fit the gap. Flexible connectors are available with compression, soldered or push-fit joints, and come in various lengths. You shouldn’t need to fit new pipe as well, but make sure you have the connector with you before cutting out the damaged section, and don’t forget to allow some overlap.
On balance, flexible connectors are more convenient than slip couplings but may not look as neat.
1. Cut out the damaged section of pipe with a junior.
File off any burrs and clean the pipe ends thoroughly, ready to receive the new couplings.
2. If using slip couplings, slide them over the pipe ends and mark their final positions in pencil. This helps when it comes to placing them over the joints.
3. Mark and cut the new section to fit the gap exactly. Prepare the ends and offer it up, then slide the couplings over it and make the joints.
Bend a flexible connector to fit the gap and make the joints. The corrugated type can’t withstand repeated bending, so take care to get it right first time.
Patching holes in copper pipes
"Providing you can drain the pipe, patch pin-prick holes in copper pipes with a blob of solder.
You can repair larger holes or accidental cuts in a similar way, by soldering on a patch made from a half-section of copper pipe bent to shape.
In both cases, make sure you clean and flux the mating surfaces before applying the solder or it won’t ‘take. Leave the joint to cool before testing."
Fill a small hole (above left) with a blob of solder. Polish the pipe with steel wool first, smear on some flux, then gently melt the solder over the hole.
For a larger hole, (above right) heat the fluxed pipe and melt on solder to cover the damaged area. Then position the fluxed patch, heat again, and feed in more solder.