A: Paste solder has always seemed to me to be a waste of time for bench work. It doesn’t seem to work as easily or as well as separately applied paillons of solder and proper flux. I suspect that this is due to the fact that it’s actually formulated more for use in soldering furnaces, which use a controlled, reducing, oxygen-free atmosphere, instead of with torch flames. In that use, paste solders work well. But for torch soldering, I’ve never liked the stuff at all.