Re: Brass radiator what sort solder and flux? With the advent of aluminum and plastic radiators I fear this is yet another dying art/talent. When Section "B" is included,, Aspect "A" isn't disturbed, as the temp from the soldering the next aspect is reduce than that of the main. As https://daltonxirxc.smblogsites.com/27273668/new-step-by-step-map-for-types-of-solder-to-use-on-aluminum-radiator