As with any lead-free solder, appropriate heating is required. The idea is to set the iron to a temperature high enough to melt the solder quickly, but not too hot. Anyone with soldering experience will get great results if it doesn't just take a little practice. The idea is to hit points for quick soldering and then dissipate the heat to avoid damaging parts. I mention this because lead-free solder can handle more heat and also transfer more heat to your parts, but these are simple issues that