Quoted from the WIKI
"You need solder so buy some. I recommend .032 size (0.8mm or 0.7mm) as the larger sizes tend to cause you to put too much solder on. How much? Go ahead and get a 1 lb spool as it’s cheaper in large volume and you will go through it faster than you think. Make sure you are getting rosin core for electronics they make some solder for plumbing that has acid as the core this is a bad mistake to make. "