elbow is on the supply side of that faucet). The more I think about
it, it sure seems like it could be air, because the solder often looks
like lava rock, instead of a nice smooth finish. I probably should
have mentioned that earlier, but it doesn't always look that way, just
on some of my attempts, but now I'm thinking even on the attempts
where I got the visible part smooth, there could still be rough parts
that I can't see (i.e.-lines/bubbles where the air is trying to pass).

My own experience is that I got a rough "lava rock" type look to the
solder when I had insufficient heat. My first soldering attempts were
made with a 6" long butane torch and it took about 5 minutes to heat
the joint sufficiently. Then after I dropped a pipe wrench on my
torch I couldn't get a decent looking joint at all. The solder would
tend to kind of glob on.

I got a new mapp gas torch and it made a huge difference, only about
30 seconds to heat the joint sufficiently and the solder would wick
right in. I noticed that you said in an earlier message that you
remove the heat when you start applying the solder. This could allow
the temperature of the copper pipes to fall and lead to the rough
finish you're observing. (Copper is an excellent conductor of heat so
if you remove the torch I'd expect the temperature to fall fairly
quickly as the heat spreads out down the pipe.) I continue to apply
heat towards the inside of the joint until the solder wicks.