Sintered Bronze

Sintered bronze is a porous material that you can't weld like solid material. The pores soak up the weld metal and cause leaks and cracks. If you have to weld the part, then only with low heat input and preferably with a process that introduces little energy. Beforehand, you should mechanically clean and compact the surface, for example by repressing or burnishing. Often brazing is easier, because the base material doesn't melt and the pore structure is preserved.