Home Improvement : Holes, Cracks in Plastic Waterlines Easy to Repair

I get my water from a well, and it must be fairly acidic. Over the years it has corroded and eaten away at the metal pipes and fittings in my plumbing system with an insatiable appetite. Whenever an old section goes bad, I replace it with plastic. And wherever the plastic goes in, corrosion has ceased. Plastic is immune to this problem.

It is not, however, immune to other common causes of leaks, such as errant nails driven during remodeling or cracks due to freezing. Even so, when these leaks do occur in plastic, they’re relatively simple to fix.

NAIL HOLES: If you accidentally drive a nail through a wall and into a run of plastic pipe, the easiest way to patch the damage is with a coupling. This is a tubular connector that fits over the ends of two pipes to fasten them together.

Saw the pipe in half, right through the hole. If there is enough give in the run of the pipe, you can then cement it back together, using an ordinary coupling in the usual way.

Apply solvent cement to the ends of the pipe on both sides of the cut. Slip the coupling onto one piece of pipe until it bottoms out on the stop molded at the midpoint of the coupling. Then quickly pull the other piece of pipe back so you can slip it into the other end of the coupling. Press it into the coupling until it too bottoms out, give the coupling a quarter turn to distribute the cement and let set.

This technique will usually work when you are dealing with the relatively small pipes used in your plumbing’s supply system. When you get a hole in the heavier pipes of your drainage system, however, it’s often difficult to maneuver the two pieces of pipe far enough apart to get the second end into the coupling.

In this case, try a slip coupling. This is just like an ordinary coupling but it has no stop or shoulder molded inside. To use a slip coupling, slip it onto one of the ends of the cut pipe, and slide it back several inches away from the cut so you can apply a liberal coat of cement to the pipe on both sides of the cut (see sketch). Then slide the coupling back up so it is centered evenly over the cut. Give it a twist and let set.

Not all pipe makers offer slip couplings. If you can’t find one, get an ordinary coupling and grind away the stop inside, as shown.

CRACKS: They are usually too long to repair with a single coupling. One solution is to cut away the damaged section, then replace it with a short length of pipe fitted with couplings at both ends. A second solution is to make a patch with a piece of plastic pipe one size larger than the pipe that’s cracked.

If, for example, a 1/2-inch line cracks, you can repair it with a length of 3/4-inch pipe. Just cut a piece of the larger pipe long enough to lap past the damage a few inches in both directions. Then take a saw and split this piece of pipe in half lengthwise.

Next, apply a heavy coat of cement to both the outside of the damaged pipe and to the insides of the repair pieces. Place the two halves of the repair pipe over the damage, orienting the seams in the patch so they do not line up with the crack in the pipe.

Finally, squeeze the patch tightly in place with two or three hose clamps, or by twisting a few lengths of heavy wire around the repair with pliers.