Trust me, that takes skill. What often happens is you get it molten but bad adhesion or you melt the parent metal or other BS. Its especially marketed for casting, at least from muggyweld.
IMO Actually putting aluminum down with a torch is often EASIER then brazing the stuff.
I figured out how to mig weld steel, stick weld steel, gas weld stainless and steel, gas weld aluminum structures that are like balanced (this is tricky, it has to do with thermal mass, but its still welds I don't like with too many random hard to prevent holes) but aluminum brazing has a special place in
hell. Personally I just.. lean towards using stainless steel now rather then aluminum when I need to weld up a structure.. for me the money spent on the steel is less then the time spent trying to fix fucked up brazes. I had modest success making frames for window screen material with Al-braze and aluminum strip (you braze up a frame and glue a window strip over it, so you have a framed removable vent cover you can screw on). It is very weak (the joint is tiny).. but I don't care since its holding up a plastic dust screen, and usually bolted right to a metal perforated plate. Stronger then epoxy in an application where epoxy is just too weak.
Now i only ever tried 2 rod types, used about 20 rods, and I had more success with a benzomatic hardware store rod then the big box of rods I bought from the welding store. But I found this interesting information
There is 2 main industry types of aluminum braze
1) patching holes in leaked aluminum hydraulics (radiator)
2) more joining type
I think my dislike may be for the type 1 aluminum braze, and using it in a incorrect application, I believe the primary application for this stuff is to fill a divet made in an aluminum radiator tube (literary a crater filler). I also got the real flux from harris for brazing aluminum (not using welding aluminum flux).
That joint almost makes me want to buy muggyweld and try it for the nth time. At this point I feel like I would rather remake that entire handle with a file then try more fucking Al brazing.
Anyway if you try it, its cheap.. if it comes to you, I am impressed, but if you can't do it, don't kill yourself over it.. its a bad process compared to like everything else metal.
Now the low temperature aluminum solders sold with liquid flux are actually.. some what decent. Its the products marketed as BRAZES that I have such trouble with.
Every once in a while I watch a new youtube video and decide to give it another try and it ends bad.
I am serious when I say the mindset I have now when it comes to approaching an aluminum braze job is similar to putting my hand into a fire.
I also noticed that every successful youtube video on this stuff uses a different type of blow torch, I am thinking that the normal benzomatic north american torch is not what you want for this application. It seems the successful people use one with a very wide broad flame.
The flow characteristic is chunky peanut butter. Silver is beautiful, this crap is like smearing tar.
To be honest if I did it I would be paranoid it will break my toe when I am carrying it. Haha as cheap as I am I would have to mail it out to get welded with a tig by someone that had the patience to figure it out and could pay for my medical bill !