How do I solder a pipe joint upside-down?
Niles 2041 asked:
I have to solder a tee onto an existing plumbing pipe. I am having trouble getting the solder to flow “up” into the joint-the molten solder always seems to want to drip back down the pipe. I am using flux, and applying the heat to the tee, not the pipe. I have had sucess with other sweat joints that were not “upside down”.
I have to solder a tee onto an existing plumbing pipe. I am having trouble getting the solder to flow “up” into the joint-the molten solder always seems to want to drip back down the pipe. I am using flux, and applying the heat to the tee, not the pipe. I have had sucess with other sweat joints that were not “upside down”.
the solder should follow the heat. heat from the joint up, but dont get it too hot.
Heat the joint to the point where the solder will melt when you touch the joint without having heat on it. Touch the solder to the joint and it will wick up into the space between the pipes. Make sure you have the joint hot enough to melt all the solder to seal it at one time. If you have to reheat the joint you’ll lose and solder already in place. It doesn’t take much to seal the joint so don’t over do it.
If you have cleaned the ends of the pipes, the inside of the tee and applied flux to all surfaces your solder joints should be fine. You may just have applied too much solder to the joints. There only needs to be a very small amount to seal each joint. Any excess will drip or run as you described.
Limit the amount of heat to the fitting. Think of the joint and the way the heat will flow by watching the color of the copper as it spreads across the area. If you have overheated the joint you may have to remove it and clean it again. A properly heated joint will wick and draw the solder around the joint and not leak or drip at all. Good luck!!!
its flowing down because it is filled.
No problem. Clean fitting and pipe till shiny. Use a wire brush for the fitting, emery cloth for the pipe. There are combination brushes that will also clean pipe. Flux with a good paste, like Oakley #5, assemble the joint, and apply heat from one side, and apply the solder from the opposite side. When the joint is hot enough, the solder will be wicked into the joint, and you can take the heat off. Rule of thumb is 3/4″ pipe takes 3/4″ of solder, 1/2″ will take 1/2″. Any excess will drip out.
If it is heating pipe, you can use lead solder, otherwise use lead-free solder. Sometimes it’s called 95/5, and is made from tin and antimony.
doesnt matter the direction. just cover the joint in LOTS of flux so the solder soaks up into that joint. and dont stand under it or youll get 500 degree metal in your eye