Hometime: Weekend Home Projects/Hometime: Weekend Home Projects.iso/media/t0808.txt

Text File | 1994-09-13 | 6KB | 98 lines

0808    PLUMBING TIPS

Working with plastic pipe
Plastic plumbing components may be the greatest thing that's happened to amateur
plumbers since the invention of running water. This material cuts with an ordinary
handsaw, and when it's time to assemble a run, you can forget about a torch, solder or
wrenches - everything simply glues together, like the parts of a model airplane.

Not all codes permit plastic, though, and those that do specify which types you can use for
drainage and for cold and hot water lines. For drainage lines your code may specify ABS
only, PVC only, or either. It'll certainly require CPVC for hot water lines.

Bear in mind, too that you can't mix these materials. Each expands at a different rate, and
there's even a specially formulated cement for each. You can cut plastic pipe with just about
any fine-tooth saw, but use a miter box to keep the cuts square. After you've made the cut,
use a knife or file to remove any burrs from the inside or outside of the cut end. Wipe both
the pipe and fitting with a clean rag.

To glue an ABS joint, apply ABS glue to the inside of the fitting, then to the pipe end. Push
the hub over the pipe and twist it to spread the glue. You need to work fast, because the
glue will set up in about a minute.

Gluing PVC pipe is very similar. But before you apply the glue, you put on a cleaning
chemical that prepares the plastic. Then you apply a cement made for PVC. The glue used
for PVC pipes actually melts the plastic a little, so the joint is solid and watertight.


Working with copper pipe
Soldering or sweating together rigid copper plumbing lines isn't nearly as hot and
exhausting as it may sound. It's the pipes and fittings that do the sweating, not the installer.

The term refers to a process called capillary action, which occurs when you heat up a joint
and touch solder to it. Just as a blotter soaks up ink, a solder joint absorbs molten metal,
making a joint that's as strong or stronger than the pipe itself.

To sweat a joint, first clean the inside of the pipe with a metal brush to eliminate impurities.
Use emery cloth on the outside of the pipe.  Next, apply flux to both pieces.

With the pieces together, heat the joint evenly with the flame from a propane torch.
Careful! The pipe gets very hot. Test for temperature by touching the joint - but not the
flame - with solder. If it melts, apply more. Capillary action will pull solder around the pipe
and into the joint.

When molten metal drips from the bottom, remove the flame and inspect your work. A
well-soldered joint has an even bead around its entire circumference. Any gaps will
probably leak. Finally, wipe away the excess solder with a damp rag.


Working with flexible copper tubing
Flexible copper tubing - sometimes called soft copper - is pliable enough to negotiate the
sharpest bend. And that's good news, because it means you don't have to install a fitting
every time a run makes a change of direction, as you must with rigid copper pipe.

And though flexible accepts the same soldered fittings used with rigid copper, you can also
make connections with compression fittings.  Realize, though, that these devices cost quite
a bit more than standard sweated fittings, and they aren't quite as strong, either.

For economy and durability, use solder connections that will never need to be broken; save
compression fittings for semi-permanent hookups and for tight-quarter situations where a
torch might start a fire.


Working with flexible plastic tubing
Think of this one as a hybrid between soft copper tubing and rigid plastic pipe. Like its
copper cousin, flexible plastic comes in long coils that you can snake through tight spots
without using fittings. As with rigid plastic, you have to choose the proper type for the
application you have in mind, and codes in your community may disallow the material
entirely.

Flexible plastic is very easy to work with. You cut it with a knife and join sections with
special plastic fittings. You also can interconnect flexible plastic with other piping
materials via transition fittings that compensate for differing rates of expansion and
contraction.

Though slightly more crush-resistant than soft copper, you shouldn't use flexible plastic for
long, out-in-the-open runs, and it should be supported every 32 inches. Be sure to clamp it
loosely so the material has sufficient room to move.


Working with threaded pipe
After your first experience with threaded pipe, you'll begin to appreciate why this heavy,
cantankerous stuff is all but extinct in modern-day plumbing systems. Cutting, threading
and assembling it are muscle jobs - and taking apart a run that seems to have welded itself
together calls for even more brute strength.

If your home was built before World War II, probably most of its pipes are threaded. This
doesn't mean, though, that you have to stick with the same material for improvement jobs.
Special fittings let you break into a line of threaded and continue on from there with plastic
or copper.

Study the way pipes and fittings thread together and you'll see that you can't simply begin
unthreading them just anywhere. Somewhere in every pipe run you'll find a union. This
serves as a keystone that lets you dismantle the piping around it.

To crack open a union, examine it closely and determine which of the union's smaller nuts
a larger ring nut is threaded onto. With one wrench on each, turn the ring nut
counterclockwise. Once it's unthreaded, you have the break you need.