For Aluminum brazing you can use Harris #10 powder flux or alsolder 500 liquid flux. Looks like Honey.( Alsolder 500 will solder aluminum to steel or brass and stainless. 500 degrees) Or if you want to do it the easy way. You can easily braze aluminum with an Aluminum stick rod. 3/32 for thin stuff and 1/8" for thicker. Treat it just like a regular brazing rod. You need to be careful like any aluminum welding but it is fairly easy. If you are not using 60 series aluminum, the best product would be AlCore Aluminum Solder. It's only about 3 degrees below braze temp so it's very strong and flows like mercury. I have about 50 tubs of it if any one wants one. Otherwise they are 10 bucks at the store. Only works on 1/2 the aluminums but the ones it works on, Nothing works better, Then there is CorAl Aluminum flux cored rods. And Welco 52 that you see at fairs, It's mostly zinc and it's best suited for fixing bullet holes in irrigation pipe. Don't ask me how I know.
