I use Harris Stay-Brite 300 to 400 degree, will solder bronze brass copper stainless to carbon or stainless blades, but all things must be clean, last cleaning with detergent and hot water, heat must be right or will burn the flux and it is allover, try a practice piece first to see how it is going to work, I allso use heat stopper on the blade to contain the heat, don't solder my blade any more, it can be a pain. Deane