..like crevices, conventional plumbing flux and when I have experienced luck with most solders, four% silver bearing solder is stronger Ultimately...kinda pricey tho... I'd Harris solder on hand at some time so no large offer for me but highly-priced if you don't have to have the strength for off highway/ https://emilianoirafi.luwebs.com/27839762/types-of-solder-to-use-on-aluminum-radiator-for-dummies