I have just put a new shower unit into a wall cavity, and have been using compression joints for all the hard to reach places. After putting everything into the wall i have discovered that the connection into the shower mixer has a slow leak, i don't really want to pull everything back out again. So what i want to know is, is it possible to solder a compression fitting? On either side of the shower mixer are male threads, that a female ended elbow screws onto. So you have to judge it just right with the PTFE tape to have it facing in the right direction and be tight, which i guess i didn't! Any ideas?