Help with Soldering Caps on the Oil Return Pipe

[Bill in SoCal]

I had a small oil leak coming from around each end of the oil return pipe. The bottom of the pipe was leaking from the bolt area, and I could not tell where the oil was leaking from at the top of the pipe. I decided to remove the pipe and replace the seals and copper washers. I cleaned the pipe down to the metal to repaint. I found that the solder at the upper end of the pipe was cracked and the head was loose (picture). I separated and cleaned the pieces (picture 2).

Before I flux and solder the cap, I remembered helping with this type of repair years ago, and there was some problem with orientation of the cap once the solder was hot. I don't remember how that was fixed. Any Ideas? Bill

 

[1931 flamingo]

I would assemble it either on the engine or mount it on a board and then solder. yes?
Paul in CT

 

[Mike V. Florida]

Put it on the engine and solder it there. A flat board won't work and I don't think it is worth the time to make up a jig just for one oil return.

It after soldering it you have a small leak just clean it real well and use jb weld on the inside to seal it.