By the way, the tank did not explode. I filled it with water, leaving
3/4 inch or so of air above the water. I stuck a torch into it, and
nothing happened, as I predicted.
formatting link
Anyway, the tank, while not exploding, just does not, flat out, accept
solder. The solder just balls on top of the steel, does NOT wet it at
all, and rolls away when exposed to the gases from the propane torch.
I tried a couple of fluxes and nothing helps.
I wonder if I should, instead, try to use brass brazing material (I
have brass brazing sticks with flux on them).
If I do so, trying to braze a brass fitting with brass braze, would
the brass fitting melt? IOW, is the melting point of the brass brazing
material lower than that of solid brass?
i