Problem SOLDERING copper pipe for water softner unit. Please advise.?

Question

I am sweating in a splice to a 3/4 copper watter line. One side of the splice sweated well, the other side will not take solder at all, it just beads up and rolls off the pipe. The two ends of the pipe and the splice had been cleaned and fluxed.

Answer 1

you also may have heated the pipe too much while soldering the other end of the fitting. try again holding the flame back a little.

Answer 2

Probably water is getting in the joint.  Stuff a piece of bread up the pipe causing the problem and then solder.  The bread will go away once the water flows.

Answer 3

try sanding both surface first, sometimes cleaning  is not enough , then flux it, join together and solder. if this still not work then one of the pipe may not be make of solderable  material.

Answer 4

probably water present. go outside and close the bigger valve.