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How to Solder
Copper Pipe Joints
By the DIY experts of The Family Handyman Magazine
Learn to solder copper pipe like a pro.
With a little
practice, anyone can solder copper water pipe.
Learn how to cut,
clean and flux pipe and fittings, how much solder to use, and how to check for
a leak.
We'll show you how
to solder like a pro so you can tackle your next DIY plumbing job.
By the DIY experts
of The Family Handyman Magazine
TIME
: One day
COMPLEXITY
: Simple
COST
: $20 – $100
Buy a self-lighting torch
Good torches work faster
A self-lighting
torch eliminates the hassles of a striker or match.
After years of
using a regular, inexpensive torch, I finally splurged on a fancy model with a
built-in lighter. They cost more, but boy, what a difference.
Just pull the
trigger to light the flame. No more fumbling with a striker or match. And it's
safer, too.
I used to leave the
torch burning just to avoid relighting it. Now I turn it off when I set it down
to avoid accidentally igniting my blue jeans.
In addition to the
self-lighting feature, look for one that burns MAPP gas.
MAPP gas produces a
hotter flame, which is better for soldering larger diameter pipes (1-in. and
larger) and brass valves.
Once you're
comfortable with how much heat to apply for a good solder joint, you can switch
to MAPP gas to speed up all of your soldering jobs.
Use a good-quality tubing cutter
Make clean, burr-free cuts
A tube cutter gives
you a cleaner cut than a hacksaw.
Use a good-quality
tubing cutter rather than a hacksaw. You'll be assured clean cuts with square
ends that fit neatly into the fittings.
The cutting process
leaves a small burr inside the pipe. To avoid creating undesirable turbulence
inside the pipe, remove the burr with the flip-out burr remover on the back of
the cutter.
Use a steel brush for complete cleaning of pipes and fittings
Brush joints thoroughly before fluxing
A 4-in-1 cleaning
tool cleans pipes and fittings quickly and cleanly.
Oils, oxidation and
other impurities on the outside of pipes and inside of fittings prevent solder
from sticking.
To clean them, you
can use just about anything that's abrasive, including sandpaper and emery
cloth.
But for the
quickest, cleanest results, buy a 4-in-1 cleaning tool like the one shown. Use
it to clean the outside of pipes and the inside of fittings for 1/2-in. and
3/4-in. copper.
Apply tinning flux rather than regular flux
Wipe both sides of the joint with flux
Tinning flux
contains a powdered metal alloy that's similar to solder.
After a thorough
cleaning, coat the pipe and fitting with flux before heating the joint. This
helps solder flow into the joint.
You may find two or
three kinds of flux on the shelf. We recommend tinning flux. It contains a bit of
powdered metal alloy that is similar to solder.
The alloy melts and
coats the inside of the joint and helps ensure a solder joint that's completely
filled and leakproof.
Assemble the pipes, then solder the joints all at once
Break the job into sections
Sand and flux one
section of pipe at a time.
We don't recommend
trying to assemble the entire plumbing run before starting to solder, but
cutting, sanding and fluxing a grouping of pipes is a good practice.
It allows you to
accurately cut and fit the pipes before soldering. With this done, it's an easy
matter to solder the joints one after the other.
Since the pipes are
held firmly in position, you don't have to worry about accidentally disturbing
a joint before it's cooled.
Heat the joint just enough to melt the solder
Don't overheat the flux
Use the right
amount of heat to solder the joint.
If you don't heat
the joint enough, the solder won't flow into it. If you heat the joint too
long, you'll burn the flux (it'll smoke and turn black) and make it difficult
to get the solder to flow into the joint.
Applying just the
right amount of heat comes with practice, but it's not hard to learn. Here's
how. Light the torch and, if possible, adjust the torch until the blue part of
the flame is about 1 to 2 in. long (this depends somewhat on the type of torch
and tip you use).
Then position the
tip of the blue part of the flame on the fitting and heat the joint about five
seconds or until the flux starts to bubble and sizzle.
Test the joint by
touching the solder to the seam on the side opposite the flame. When the copper
is hot enough, the solder will melt like butter.
Move the flame away
from the joint and feed about 1/2 in. to 3/4 in. of solder into the joint. The
solder will flow into all areas of a properly cleaned and fluxed joint.
Then to make sure
the joint is completely filled, run the tip of the solder quickly around the
seam. It's easier to reach around the backside of the joint if you bend a hook
on the end of the solder before you start.
If the solder beads
up and rolls off rather than flowing into the joint, you've probably burned the
flux or the copper isn't clean enough.
You'll have to take
the joint apart to clean and reflux it before trying again.
Make sure the joint is filled
Cutaway of soldered joint
Complete cleaning
and proper fluxing and soldering result in a joint like this that's completely
filled with solder.
With practice,
you'll know by feel when you've successfully soldered a joint. The solder will
flow easily and completely around and into the fitting. But when you're just
starting out, it's a good idea to inspect the joints for voids.
A good solder joint
should have an even band of solder showing all the way around.
If you see an area
that looks as if it needs more solder, brush a little flux onto the joint. If
the joint is still warm, the flux will melt and flow into the void. Then reheat
the joint and resolder.
Don't Burn Down the House!
I'm always a little
nervous when working so close to wood with a flaming torch, especially when the
water is turned off.
That's why I make a
point of filling a bucket with water first. I also keep a fire extinguisher
handy and protect flammable materials with a flame protector.
Required Tools for this Project
Have the necessary
tools for this DIY project lined up before you start—you’ll save time and
frustration.
·
Soldering torch
·
Tube cutter
4-in-1 pipe
cleaning tool, Flux brush, Flame protector cloth
Required Materials for this Project
Avoid last-minute
shopping trips by having all your materials ready ahead of time. Here’s a list.
·
Lead-free solder
·
Tinning flux
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