In regards to Cwlondon question,I don't see anything wrong with it.In fact he is always been a gentleman and a polite one in all his posts.Trying to learn something is one of the reasons we all come in here.
I wouldn't mind learning to solder electonics myself.
I've done copper pipes though and I am very good at it.In fact even though I am not a plumber I took fair size plumbing jobs on the side to make an "extra buck"
One thing I found with copper is to MAKE sure to polish all fittings that make contact and wipe clean and flux good all surfaces to be soldered.That alone is 90% of the battle .Indeed is correct to apply heat on the fitting and once hot it will suck the solder in.
Best to all
George