/// Solder Aluminum? Check the Ham Radio ads for low melt rods. The distributors put up tables at Hamfests and demonstrate the rod on coke cans with a torch. The most recent published data is to use an oil puddle scrape the site with a stainless steel knife blade or brush through the oil then heat until the object being soldered will melt the applied solder.

That last method is messy particulary when you are trying to solder a crack that leaks the oil as fast as you pour it on. The demos use an inverted coke can so that the bottom will hold the solder in the depression at the bottom of the can.

Harbor Freight sold the rods, if they are still in business.