Flux

[ralliart]

i just bought some solder today and it came with something called flux i want to know what it is, and when do you use it, why do you use it.

thanks

[KMac]

You put flux on the item you wish to add solder to. It helps the solder flow onto what you are soldering.

[SteveK]

I brush it on something, such as a motor tab or the end of a cell, and then I will tin it with solder. It helps the solder stick to the part, and helps with heat transfer.

You don't need a lot, just a very light coating.

[Boxxer]

Flux etches the surface to make it rough.

[thunderbt3]

eh, those might be some good reasons but when i took electrionics classes in highschool, we learned that flux helps cleans the surface so theres no oil or grease on what ur soldering.