After several horrific problems with soldering copper joints over my head, getting responses from this forum and searching the internet in general and You Tube specifically I modified my technic and those changes seem to have resolved my problem.
All the 7 joints were over my head and in fairly tight places under the floor reached from my crawl space.
I did most of these before but was not as scrupulous.
1) Clean the inside of the fitting and the outside of the pipe until it is shiny with no specks.
2) Make sure there is no water in the pipe in the area of the fitting. Heat the pipe with the torch if need be.
3) Support the pipe so the fitting and pipes are eye sight straight.
4) Wipe the inside of the fitting and outside of the pipe ends with a clean dry cloth and do not touch them with the hands again.
5) Flux the inside of the fitting and the ends of the pipe with a clean brush and assemble fitting.
6) Get comfortable so it is possible to move around the fitting as it is heated and soldered before lighting the torch by moving other tools back.
7) Heat the fitting only blowing heat back to the pipe and moving it side to side and angling as best possible to have flame blow over the top and sides of the fitting. I notice the flame will actually bend some.
8) Bend the end of the solder 1" and then bow it to reach around the fitting seam and keep your hand out of the flame.
9) Watch for the Flux to fizz and then repeatedly test the end of the solder to the fitting seam to see if it melts.
10) Feed solder into the top and sweep it along each side. The reason I bend the solder end 1" is that I find on 3/4" pipe it takes about 3/4" of solder to fill the joint and an 1" allows some to fill the joint and drip out the bottom. I guess 3/4" would work for 1/2" pipe.
11) Wipe the joint clean of Flux and wait 30 minutes for the pipe to cool before pressurizing the pipe.
Thank you for everyones input.
#5 should be done after step #1, and skip step #4. Don't "measure" the solder, just use whatever you have to in order to make a good joint. "30 minutes" is about 27 more than you need to cool the joint.
Licensed residential and commercial plumber