wrote in message
ps.com...
On Oct 23, 10:23 am, Heathcliff
wrote:
Gee it sounds like what you are doing is right, and the responses have
been good. One more dumb question: while you are soldering, one end
of the pipe is open to the air, right? (So pressure doesn't build up
inside) -- H- Hide quoted text -

Uhh, no! And maybe that is why I'm having so much trouble with this
"last one", since all of the others wouldn't have this issue since the
pipe was still open. However, I did do 2 temporary end caps prior to
this part of the job, and those went on fine without anything "open".

Unless the fact that I have all of the nearby faucets open counts?
This is for a shower faucet, and I have the sink faucet open (both hot
and cold), and also sink and tub in the bathroom that shares a wall
with this one, plus I have the hose open at the water shut-off valve
coming in to the house... I just open all of those up because I want
to make sure water is out of the lines, so I just leave them open,
plus the water shut-off at the house has a tiny leak, and leaving
these other faucets open keeps the pipes I'm working with free of
water.

I guess I'll open the shower faucet I'm installing, since it can't
hurt (unless I forget to close before I turn the water back on, then
my wife gets wet since she stand in front of it with a 2-way radio to
let me know if I need to turn the water back off in a hurry).


You've gotten lots of good advise but I'll add one trick taught me by Master
plumbers. If you have ANY risk of water seeping toward your joint, you need
to stop it far enough back and long enough to complete the solder joint.

The trick? Get a slice of white bread -- the doughier the better. Wad it up
so that you can shove a bunch of it far down the pipe; a pencil makes a good
ramrod. Make sure it fills the entire diameter of the pipe. Pack it in both
directions if necessary. While you're soldering, the bread will absorb the
water. When you turn the water on, the water will dissolve the bread and
flush the pipe clean.

I had been soldering copper for decades and running into all sort of
problems getting the last traces of water out of the pipe until I learned
this trick. Believe me -- it works!

Best of Luck!