The supports were originally attached with good old-fashioned plumber's solder, and the rest of the radiator is held together with the same stuff, which melts at about 400 degrees F. If you heat any part of the radiator to 1200 degrees to melt the silver "solder" the entire radiator will likely return to its component pieces. I might use that stuff if I were brazing a bicycle frame but certainly nothing near a radiator.
