GARTHWILSON wrote:
Flux is the goop that is activated by the soldering heat to remove or prevent oxidation on the metals you're soldering, so the solder will stick. Just get rosin-core solder, and that will be adequate for most soldering. I also have flux in a tube and some in a bottle, with applicator, but I seldom use those. The solder wire is hollow, and the hollow space is filled with rosin flux, so the flux feeds out at the right rate with the solder, and when the solder melts, the flux is right there immediately. (It smokes too. That's normal, so don't let it scare you. Nothing's wrong.) Get 60/40 rosin-core solder. The 60/40 refers to 60% tin, 40% lead. That combination is used because it's approximately the mix that melts at the lowest temperature, a temperature lower than either tin or lead by themselves melt at. That is, it's the eutectic temperature. The EU does not allow lead anymore, and that causes various problems. If you're in the US or any of a lot of other countries, you can use lead. Do not use water-soluble fluxes. (I don't think I've ever seen water-soluble flux in the core of solder wire though.)
I'm in the US. I was able to order 63/37 tin & lead, with rosin core. From what I've seen online, you have to wash the parts off with IPA after soldering to remove the flux?
Jon