Was: Soldering troubles
The most basic is a simple paste of borax; but not the washing powder, that's not pure borax. There are plenty of prepared hard soldering fluxes for sale by your favorite tool supplier.
BTW, anybody still grind their own borax?
I see this one pop up periodically. Standard '20 Mule Team Borax" is
Hydrated sodium borate, Na2B4O7 -10H2O at the 99.5% range. The rest
is inert minerals.
What people confuse it with is Boroxo (which is borax and soap) and
Borateem (which was a borax/non-chlorine bleach mixture whose
current formula has no borax at all)
Ron Charlotte – Gainesville, FL