JOINING
COPPER PIPE/TUBING:
Copper pipe and tubing can be joined in three different ways: with
solder (sweating); with compression nuts; by flaring. The steps
for each system are detailed below:
Solder (Sweat) Joined. Measure and mark the length of pipe
needed. Measure twice, cut once.
- With
a tube cutter, cut the pipe to length. You can also use a hacksaw
and miter box to cut the material, but a tube cutter is recommended
because it cuts the pipe perfectly square so it fits tightly against
a tiny "shoulder" inside the pipe fittings. A hacksaw in a miter
box also produces true cuts, but the metal residue on the pipe
after the cut has been made must be removed with a cone or triangular
reamer. The tube cutter has a built-in reamer for this job, although
the tube cutter usually leaves a clean cut.
- If
necessary, remove the burrs left by the cutting operation.
- "Dry
fit" the fitting onto the pipe. Does the end of the pipe fit squarely
against the shoulder in the fitting? If not, recut the pipe.
- Make
all necessary cuts in the complete pipe run and assemble the run
dry. Make any adjustments at this time.
- With
steel wool, shine the end of each pipe where it will go into the
fitting so the copper is as bright as a new penny coin. Do not
touch the shined metal with your fingers. You fingers leave grease
on the pipe and any grease tends to prevent the solder from sticking
properly.
- Coat
the shiny ends of the pipe with paste soldering flux. Use a flux
brush for this and make sure that the pipe as the end where it
goes into the fitting is completely covered with a thin layer
of paste flux.
NOTE:
Rigid copper pipe is assembled with sweat-soldered fittings using
"soft" solder. Solder used to be a combination of tin and lead.
However,
codes have been recently changed to eliminate lead from the solder
formula. Under "grandfather" code "extensions" tin and lead solder
may still be sold in stores where you buy materials. Be sure to
check the store concerning any code restrictions on tin/lead solder
in your area.
Also:
Solder generally is used in wire form, but paste-type solders
also are available. They consist of finely ground solder in a
suspension of paste flux. If you use this product, (do no use
acid-core solder with copper pipe) there are four rules to follow:
1)
Wire solder should be applied in addition to the paste. The wire
helps fill voids and aids in displacing the flux, and if it is
not used you may have nicely tinned surfaces with a poor joint
resulting from a lack of continuous solder bond.
2) The
paste solder must be thoroughly mixed if it has been standing
in the container for more than a short time. The heavy solder
has a tendency to settle to the bottom of the can, and taking
material from the upper portion of the container will result in
a mixture that is mostly flux and little solder.
3) Do
not depend on the flux to clean the end of the pipe. Use steel
wool.
4) Remove
any excess flux. Only enough flux should be used to lightly coat
the areas to be joined with solder. Use a flux brush or the end
of a piece of wire solder to apply flux to the copper pipe.
- Slip
the fittings onto the pipe and make sure that the pipe is tightly
set against the shoulder in the fittings. If the fittings do not
have shoulders, the pipe should go into the fitting about 1/2
inch.
- With
a propane torch, heat the fitting-not the pipe. Touch the solder
to the joint between the fitting and pipe from time-to-time while
heating the fitting. When the fitting is hot enough the solder,
touched to the joint, will by capillary action be pulled back
into the joint.
If you look closely you can see this action. When the joint is
full of solder, the solder will automatically form a tiny bead
around the joint. At this point the joint is soldered or sweated.
You do not have to run the wire solder around the joint. Just
hold the solder at one point and let the capillary action do the
work.
- Let
the joint cool by itself; don't dip it in water, since sudden
cold sometimes causes the joint to crack. It takes only a few
minutes for the metal to become cool enough to move, if it has
to be moved.
- Complete
each joint as detailed
SPECIAL
NOTES: Copper pipe can not be properly sweated with water in
the pipe. The water from any installed pipe should be drained. If
there is still moisture in the pipe when you start to sweat the
joint, use this trick: Stuff a wad of fresh bread into the pipe.
The bread will absorb the water. Then sweat the joint. The heat
will turn the bread into "burnt toast," which will flush out of
the pipe when the water is turned back on.
If,
when the water is turned on you have leaky joints, turn off the
water and drain the pipe as best as you can. Then heat the leaking
joint at the fitting and pull it apart after the solder has melted.
Use
pliers for this and wear heavy gloves. The pipe will be very hot.
Now, heat the pipe and wipe away any solder with a cloth. Again
wear gloves and be careful. The pipe should be hot but not cherry
red; just enough heat to melt the solder. After wiping, the pipe
should have a thin coating of solder on it. Do the same with the
inside of the fitting. Be careful. The fitting also should have
a thin coating of solder on it. This is called "tinning."
Apply
new flux to the pipe and fitting, and slip the pipe and fitting
together. Heat the fitting with the torch and touch the joint with
solder until you see the tiny bead appear at the joint. The pipe
should be perfectly joined.
If
you are soldering valves (faucets) to copper pipe, disassemble the
valves.
The
heat can damage washers in the valves. A regular propane torch will
handle pipe and tubing up to about 1 to 1-1/4-inches in diameter.
Over this size, use a Mapp gas touch or an oxyacetylene torch that
you can either buy or rent. These tools supply the necessary heat
for the larger sizes of pipes.
