how do you make homemade flux???

I saw the instructable about making flux out of pine cones but i have a problem: WTH do i get pine cones in a tropical country??? I did some research and found out hydrochloric acid is a component in some fluxes out there. I wonder if i can use lemons, an abundant supply in the form of calamondins here in the Philippines.
EDIT: it's for soldering

onrust6 years ago
I have did use a citrus base flux for domestic water applications years ago in California. I didn't care for it because you had to use low heat or it would dirty the fitting and leak.
rickharris6 years ago
For soldering or brazing or what?? I don't know for sure but I would worry about the sugar in citrus fruits.

For brazing, borax is the standard flux and is a common washing addative.

... And are you sure you need flux for whatever you're doing? For soldering, I'd suggest a flux-core solder.

(For most electronic work you emphatically do NOT want an acidic flux; it will etch and eventually may destroy your circuitry.)
lemonie6 years ago

I used boiler-treatment in the past,it had a lot of phosphoric acid in it.
You could try a lemon-juice reduction and see what it does.