[simplechamp]

I thought I read somewhere that 63/37 solder is slightly better than 60/40, something to do with the melting point and it being more uniform in the 63/37. But I have never really looked into that to see if it has any merit, I still always use 60/40 with good results.

The only time I use additional flux is a tiny dab when tinning heavier gauge (8-10AWG) wire. Seems like it helps the solder to wick into all the strands easier and more evenly. Not sure if it's just me, but without the flux sometimes the wire seems to be a bit stubborn in absorbing the solder, the flux mainly helps to get it started.