Its a minor leak I just noticed and probably only occurs only after water flows through the joint. Thought it was condensation. Under std. pressure and no flow, little if any water on tissue paper. I am just assuming its gonna drip some (more) after I run it some, given the evidence. Drying/wicking now. Some time ago, I may have aggravated a little with a tug too hard.
If there is in fact a hole/crack/passage caused by stretching open a crack at the joint and if the solder should be enough to COVER that area can the joint be reheated with a (std. old legacy technology type) propane torch. Can solder be added when its at temp? Its an older thing, thats known. There isn't any reason I couldn't drain the line, but is it possible to take this to extremes, or not be too concerned (more later).
Secondly, what about those tapes that are supposed to wrap around and seal. The drip is likely almost something to turn away from, change the dressing every once and a while. Can these tape products, or I've even seen a spray can, work for a little problem like this. Its really a bit of an pain, the location to just fix it with another elbow spliced in. I have one tape called "Magic Wrap" by Glasgow mfrng, London Canada. Black rubber/plastic electrical tape sized roll 1" x 16'. Pkg says "forms a solid rubber wrap", shows a brass garden faucet outdoors being wrapped, "stretches to 3x its length", "water tight and air tight to 100psi", "strong, long, all temp, conforms". I have no clue of the pressure involved. It does not look like a fiber tape, but can't ell cause its got backing on it. Don't know if I need could another type either.
ah, here's the one I have: