Copper water line sweat fitting puzzle
To All,
I recently finished replacing about 100′ of old galvanized water line with copper line. This project had many unions, T’s, el’s, 45’s, shut-off ball valves, dielectric unions, reducers and so on.
My prep for each solder joint was to scour the outside of of the CU pipe with a wire ‘brush’ similar to those for cleaning auto battery terminals. The inside of the union was again scoured with a brush made for the purpose. Each joint was left bright and shiny. Flux was thinly applied, the joint assembled and soldered. If I were soldering an el or a T, all piping was soldered at once. I had no problem until the very last T.
On this final solder connection, I could not get one section of the T to take solder. My first thought was that I had forgotten to either scour the joint or had forgotten to flux it. The solder readily adhered to the copper pipe outside of the joint, but not the joint itself. After shutting down the propane, I grabbed the joint and it came apart easily. There was absolutely no solder in it. I scoured the pipe and the inside of the T joint, fluxed both and put the flame to it. The solder flowed normally and the joint held. I did wrap the other two sections of the T with a damp rag before soldering so as not to affect either of those solder connections.
So, naturally, I am puzzled as to why this last joint failed to take the solder. I don’t think you could say that it was because I failed to either scour or flux because the pipe outside to the joint took solder without either. The only possibility that may exist is the heating of the T but in my opinion, this is a weak argument to make. I say this because the heat required to make the other 2 good joints would (or should) have been sufficient to make the last section hot enough to take the solder. I don’t do this for a living so have no expertise to fall back on. I’m only trying to dissect the problem and find a solution.
I have no problem now, but would like to know if anyone has ever had this happen and what they think the cause was. I would hate to have this happen one more than 1 joint.
Thanks in advance to all who respond.
Regards,
Phillip
Edited 9/1/2004 10:57 am ET by PhillipB
Replies
Open a valve somewhere. When you heat the pipe pressure builds up inside and blows the solder out.
The only things I know that will cause this are as stated above pressure in the pipe or contamination. Sounds like pressure to me too. DanT
Dan,
Thanks for your message.
I would have never thought of that and it makes good sense because I WAS working with a closed system: One end was the hot water source which was blocked by the ball valve and the other two ends were blocked by hot water faucets. In addition, like I mentioned, it was my LAST joint to solder so the whole system had plenty of time to pressure up from the heat.
And also - I just recalled this bit of info AND I just took another look at this particular joint - I was never so sloppy as to get solder 1/4" away from the pipe-connector point which is exactly where all of this solder ended up! I always held the solder at this junction (like you're supposed to do) not 1/4" down the pipe.
Thank you very much for your time. Next time I'll be sure to leave the faucet valves open. Lesson well learned.
Regards,
Phillip
Edited 9/1/2004 1:06 pm ET by PhillipB
The fact that it was the last fitting was really the only clue I needed.
Been there, done that.
Right on, Dan!
This one ranks right up there with those lessons that a person doesn't ever forget.
A real stumper for me.
Thanks again.
Regards,
Phillip