Opt for a flux. Much like the solder, the flux must be specialised for aluminum or for The mixture of metals you propose to hitch. The best choice is to get the flux with the similar resource as your solder, as They're very likely intended to operate alongside one another. https://automotiveengineering87919.blog-kids.com/27439326/5-essential-elements-for-types-of-solder-to-use-on-aluminum-radiator