The FinitEasy fillet weld grinder was developed by Cibo Abrasives precisely to solve this problem.
Stage 1: SA/5/T31 will belnd a fine fillet weld
Stage 2: Use the felt disc with a touch of the pink (PV/102) polishing soap on the edge
Stage 3: Remove any excess polish with a lint free cloth and the vienna chalk (PV/103)