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beecrofter[_2_] beecrofter[_2_] is offline
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Default Having trouble soldering copper pipe

On Oct 23, 12:57 pm, wrote:
On Oct 23, 11:33 am, Jeff Wisnia wrote:





wrote:
I'm redoing my shower, all 1/2" copper pipes. I've done two couplers,
1 elbow, and 3 threaded connectors... and they all went fine. Just
one other elbow had a small leak. I tried at least 10 times last
night and continue to have leaks. Maybe I just need to try again
tonight with a fresh mind, but...


One problem I've got now is that the two ends going in to the elbow
have solder on them. I've sanded them until smooth (they are still
solder color, but smooth, is that okay?) and used a new elbow, and did
that a couple times last night, but still no go. Is it okay to sand
off the old solder and keep trying this way, or do I really need to
start with all new pipe? It is easy to keep using new elbows, I've
got plenty to spare... but I can't really cut back the pipe, not
without adding yet another fitting (another coupler) which just seems
like even more work, and eventually I'll have it cut back to the slab
and not be able to continue.


The elbow fits well, nice and tight, just like all the others I did,
so I have no idea why this one connection is giving me so much
trouble. I did only do one other elbow though, so maybe I just got
lucky on that elbow. Is there anything special you need to do when
doing elbows? I've tried doing one end at a time, and also tried
heating in the middle of the elbow and running the solder around both
ends, one right after the other (while still hot, so they both cool/
harden at the same time).


I've read a lot about soldering... but, how long do you need to wait
before testing? The pipe seems to cool pretty fast, so I've been
testing within 2 to 5 minutes, is that not long enough? I kind of
wish I could find an elbow with about 6" of pipe on each end, so I
wouldn't have to worry about messing up one end while working on the
other.


At the risk of telling things you probably already know and are doing.......


Are you SURE there's no water left in the pipes which is somehow keeping
the pipe from getting up to soldering temperature?


Are you cleaning the INSIDE of the part of the elbows which fit over the
pipe ends, using a wire brush or abrasive cloth until they are bright
and shiny copper?


Are you using a decent paste flux wiped onto the pipe ends and the
inside the elbows?


Heating in the middle is not necessarily the best way to do it, you
should probably move the flame from one side of the elbow to the other
while heating if you're going to solder both ends "at once"


Other than that, I can't think of why you're having problems with one
elbow unless someone's put a curse on your plumbing.


HTH,


Jeff


--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.- Hide quoted text -


- Show quoted text -


I'd cut the pipe back and add a coupling. You say you keep sanding
the used pipe ends and get it to clean solder, but the problem may be
beneath the solder. For example, if the pipe was not initially
properly cleaned and fluxed, the problem may be under the thin solder
coating that is left, where there is some contamination causing
problems again each time it reflows.

The other choice is to sand off all the solder on the end of the pipe
down to bright copper. Make sure you clean the inside of the new
fitting too and then apply flux. Using the wire brushes that are
made specifically for that is the best way. They also make them for
use on the outside of the pipe and work much better than sandpaper.
They look like a doughnut and you just rotate it around the end of the
pipe.- Hide quoted text -

- Show quoted text -


Usually you can just flux and reheat the pipe that has some solder
left on it and use steel wool to scrub and wipe it off while molten.
Pre-tinned the joints go together even easier.
Try warming the pipe with the torch before dry fitting the parts, you
would be amazed how much steam some condensation can make and it will
push molten solder out of it's path.