I had trouble as a novice with the RS 2% silver. I've used a lot of Kester 44 the past year. It melts at a lower temp and flows very freely. Only drawback is that it cools down to a not-so-shiny grey and might cause you to think it's a cold joint. Or worse, make you go back and apply more heat and fry a component. I've done both! Cardas Quad Eutectic melts and flows beautifully. It leaves a shiny joint that even acetone on a Q-tip rarely shows flux deposits. Buy it from M Percy much cheaper than elsewhere.