It was worth staying up an extra 15 minutes after work, burning the gas and messing up a few feet of aluminum to do this lil exercise
from the end:
a piece of scrap angle iron
a piece of copper water pipe
a tin tab, like for doing roofs
an un plated gr5 bolt
bar stock is 1/4" x 1" aluminum
i used oatly silver bearing solder, oatly h-20 paste flux, and the flux with no lid is burnley paste flux. I also used plain old 60/40 rosin core radio shack solder, and I used an alumallow rod ( copper 2.5%, aluminum 3.4%, ballance is zinc )
outter pieces are silver soldered on, inner 2, copper is done with alumalloy rod, and tin tab with 60/40
used burnley on the 60/40 as it is an agressive flux.. moreso than the oatly anyway.
no tricks, no gimmicks, and no cold solders.. these are bonded.. i showed the backside in one pic of the steel angle iron stuck to the aluminum so that you see there is no screw or anything.
nothing more than cleaning up the metal with a bit of 800 sand paper, and then the flux. blue plumbers torch was the heat source.. items were soldered on in order using the various solder types and fluxes.
You CAN solder aluminum and steel together.
you CAN solder copper to aluminum
soundguy