..like crevices, normal plumbing flux and while I've experienced luck with most solders, four% silver bearing solder is more robust Eventually...kinda high-priced tho... I'd Harris solder readily available at enough time so no big deal for me but highly-priced if you do not will need the strength for off highway/ https://jasperubfhi.blogunok.com/27519172/types-of-solder-to-use-on-aluminum-radiator-can-be-fun-for-anyone