Aluminum can be very, very tricky to weld because unlike steel that glows from dull red to bright red to white hot, aluminum just soaks up heat to a certain point and then becomes a puddle on the table or ground below. It takes lots of practice to get it right and when you get it wrong, it can go horribly wrong.

So, I don't know how important these items are to you but sometimes, paying a PRO to take on highly skilled tasks, turns out to be the cheapest solution.

They were hawking these aluminum brazing rods at a local
county fair type event, a few years ago. The demonstrator
was very adept at welding aluminum pop cans together and
the product appeared to work well. So I got sucked in and
bought them. Oh, and he said it is very important to clean
what you intend to weld with a 'stainless steel' brush,
which they conveniently also were selling. I have tried
them several times since and could not get anything close to a puddle with the rods. I suppose if I want to weld some pop cans together they might work.

Aluminum melts at 1100 degress brazing rods melt at 725 degress so keep temperature just able 725 degress stick rod to heated metal so tell if temp high enuf melt brazing rod. You melt rod from heat metal not torch flame yes clean with stainless steel brush.

That aluminum brazing rod worked about like trying to apply plumbers lead to an automobile repair, instead of the auto body lead. You could heat and heat the stick of plumbers lead, and suddenly it would melt and run off the work piece! As for auto body lead, it had a different formula, as it would soften with correctly applied heat, and it could be worked with a wooden paddle, into a semblance of the final form you wanted to achieve, then carefully carved with a body file, then sanded to the final shape.
If you have watched the show on TV, where a shop built Hot-rods, and did custom work, The old guy sitting there leading the cowl of an old Roadster, was how it was done!
Several years after i had left one place of employment, my former employer asked me to come back and lead in a fender on an Alpha-Romeo, because nobody who worked there knew how to apply body lead! Plastic made huge in-roads on using lead for auto body repairs, and now it is hardly used, except for Custom work!