Q: Is paste solder as good as wire or sheet? It certainly seems like it would be easier to deal with.
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.
by Peter W. Rowe M.F.A., G.G.