Question about a difficult to solder type of copper

[danbb]

Last time I worked on a house this age, I ended up just cutting the pipe back until I had a piece that would take solder, one fitting, however, got the 15% treatment because my flux kept washing out. The 15% stuck to it no problem

[gwoner]

Had same problem with a unit heater. Copper cleaned, still wouldnt take. Picked up some Silvabrite 100 solder and wahlah, 95% tin 5% silver, problem solved. Stay away from water based flux.

[sweat hog]

Let me rephrase it to "field annealing" lol. If my terminology is incorrect then please correct me. Annealing is the process of heating a metal until it's properties change. Field annealing would have occured when trying to solder with maybe water in the copper. The solder won't take and the copper becomes a greenish purpleish color. Also hard and brittle. Even after cleaning the copper and adding flux, the solder won't take. I practice my annealing skills normaly repairing condensate drains in freezers when there is residual ice in the line. I've heard an old plumbers trick is to stick bread in the pipe to absorb the water while the joint is being soldered, then just flush it out with a little pressure. Never tried that.

Supply run to subway, charge in there and ask how much for the buns?.