I am wondering how "safe and effective" is to use compression method
instead of soldering for joint of copper pipe and fittings? I am not
comfortable with soldering, but not sure using compression is
"water-tight enough" for joint or not, thx.
I'm not a big fan of compression fittings for domestic water
but............many homes have them & they work just fine.
I'm old school, when working in copper I solder.
The compression fittings are faster but potentially troublesome &
harder to work with down stream IF repairs are needed,
If done correctly the compression fittings are just as good as the soldered
connections. I work in a very large plant and we have thousands to millions
of copper and stainless steel connections using the compression fittings.
Anywhere from a few pounds of air to several hundred psi of various
Did you also notice that that plant has an entire crew of
maintenance workers to constantly check and repair anything
that breaks or fails? And hundreds of instruments in the
control rooms to let you know when something is leaking or
If you have those in your home, and all of the compression
fittings are exposed, then I would recommend going with the
Due to the propensity of compression fittings to fail, I only
use compression fittings where they will be visible. Solder
for everything that will be concealed.
Compression fittings can last for years and mostly they do
last, but they are much more likely to fail over time than
I've had problematic compression fittings over the years... Often I
get fed up enough with them and change them to flared fittings... It
seems that with compression fittings, there is a certain amount of
force that you can use to tighten the fitting -- too little and it
will leak, too much and it will deform the fitting and also leak...
With flared fittings, it seems that you can really torque it down and
it won't deform and start leaking... YMMV, of course...
For the most part (in typical residential plumbing) hard copper pipe is
soldered except for a few things like supply valves at sinks, After that
they are useful for repair but I wouldn't use them in a new setup if only
for the vastly higher price per connection. Soft copper tubing usually uses
Besides do they even have compression fittings for elbows, tees, 45s, caps.
One great advantage for repair is that they can actually be connected
without shutting off the water (yeah, its messy and you probably need to
open a faucet to keep the pressure low) or completely draining the pipe.
On 6/8/06 10:09 AM, in article
firstname.lastname@example.org, " email@example.com"
This reply probably does not apply but...
Cold welding is possible and definitely will not leak. Oxygen-Free High
Conductivity (OFHC) copper is used in vacuum tubes. The vacuum seal is
formed by pinching of the copper exhaust tube with a tool that looks like a
bolt cutter but has rounded jaws. The copper flows and becomes vacuum tight.
Probably, this is not what you mean by a compression fitting.
-- Ferme le Bush
I have a strong preference for solder. I've used an industrial type of
compression fitting in my lab with great success....but the
hardware-store type of compression fitting seems to be rather
hit-or-miss. Sometimes they work, sometimes they leak.
Suggestion: You might consider buying a few feet of 1/2" copper pipe,
a dozen solder fittings, solder, torch, tubing cutter, flux, cleaning
brush, etc.. Cut the pipe into 2"-3" lengths. Find a good book in the
library on soldering, follow the directions. Practice soldering a few
dozen joints. You will gain experience and confidence.
Cleaning is the important step.
Best -- Terry
I am inclined to solder, but in a house I had for 35 years, I was
reluctant to solder some pipes near the water meter. I was putting in a
"wet" darkroom for photographic work. I made it a point to CLEAN the
tubing well, and to lubricate it well (threads, pipe) before using the
compression fittings. For the 4 additional years I owned the house, I
had no problems at all with the compression fittings. Clean was the
trick, I believe.
I am able install successfuly a water hammer arrester for the dish
washer using two soft copper pipes. It seems to me that only soft
copper is suitable for compression fittings at least as the Balck &
Decker home repair book suggests. But the book also mentions that
copper with type M is also suitable for compression fittings. The house
I own is over 25 years old, not sure what type of copper was used
Actually, I did practice a couple of times like you mentioned, but I
cannot tell whether the thing I solder is leaking or not. I never try
on real thing since I fail, I may end up calling emergency repair(the
thing I want to replace the valves under the sink which can not be shut
off without shutting off main valve), it may be costly than just call a
plumber to do it for me.
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