If you order from All-Spec just make sure you get only RA or No-Clean solder unless you intend to wash your assemblies in hot water and dry completely before use. RA is easier for the novice than no-clean, but either will work. Water soluble solder has an acid core that will over time corrode your finished work. This is not the same as acid core plumbing solder. In commercial electronics manufacturing many assemblies are manufactured using aqueous based flux and washed in a DI (DeIonized) water. All of my boards all get built using water soluble flux and washed, but one must be careful with certain components and water. It is best left alone. I have been in the electronics manufacturing industry for over 20 years and still see people using water soluble in incorrect applications. It is never to be used for wires, the flux will make it between the insulation and the wire and will eventually lead to failure. This very thing made me a bunch of money years ago doing re-work on a whole bunch of video switching equipment that had all of the internal low loss coax connections done in water soluble or aqueous flux solder. Hours and hours of re-work at time plus materials. It was like printing my own money.
