Opt for a flux. Much like the solder, the flux ought to be specialized for aluminum or for the combination of metals you propose to join. The easiest alternative is to buy the flux from your very same resource as your solder, as they are possible meant to work collectively. https://autobody51603.sharebyblog.com/27191249/helping-the-others-realize-the-advantages-of-types-of-solder-to-use-on-aluminum-radiator