rec.crafts.metalworking
zinc solder on aluminum

After some time trying to get the much heralded zinc solder rods (No Flux
Needed!) to work on aluminum, a short paragraph from a maker's instruction
showed the way: heat the aluminum while rubbing with the tip of the rod. When
the aluminum gets to adequeat temperature, the zinc will melt & the rubbing
clears the aluminum oxide. In other words, heat the aluminum not the zinc.
The zinc makes an excellent thermal controller too. The aluminum/zinc area
didn't show the slightest hint of excess temperature.
Now, a flux is needed for situations where aluminum to be soldered can't be
reached with the zinc rods. Any suggestions?

Hul

Hul Tytus wrote:
rec.crafts.metalworking
zinc solder on aluminum

After some time trying to get the much heralded zinc solder rods (No Flux
Needed!) to work on aluminum, a short paragraph from a maker's instruction
showed the way: heat the aluminum while rubbing with the tip of the rod. When
the aluminum gets to adequeat temperature, the zinc will melt & the rubbing
clears the aluminum oxide. In other words, heat the aluminum not the zinc.
The zinc makes an excellent thermal controller too. The aluminum/zinc area
didn't show the slightest hint of excess temperature.
Now, a flux is needed for situations where aluminum to be soldered can't be
reached with the zinc rods. Any suggestions?

Hul

You need the zinc, or zinc bearing solder, not flux for soldering aluminum.
Heating the base material and not the solder is standard for any process
except maybe wave soldering. Source: visiting factories that solder aluminum
for making electrical connections.