Select a flux. Very similar to the solder, the flux really should be specialized for aluminum or for the combination of metals you plan to join. The easiest selection is to acquire the flux from your identical resource as your solder, as They are really probably meant to function collectively. https://autocollisionrepairestima88617.mybjjblog.com/how-much-you-need-to-expect-you-ll-pay-for-a-good-types-of-solder-to-use-on-aluminum-radiator-40873913