REMOVAL OF WELD SEAMS
The correct choice of abrasive tool (flap disc, velcro disc, sisal and/or cotton discs for polishing) is fundamental to achieve the desired degree of finish. The choice of cycle obviously also depends on the material being worked on (carbon steel, stainless steel, aluminium) and any subsequent treatments the parts will undergo (chrome plating, galvanising, passivation or other).
Assuming you have an angle grinder for roughing and a roto-orbital sander for finishing, a rough cycle could be as follows: First pass Weld removal with a flap disc. For large welds a coarse grit (grit 40) may be required: in this case a second pass with a finer grit flap disc may be appropriate, to reduce the finishing time of subsequent passes. In order to reduce grinding times as much as possible, especially on stainless steel, the use of ceramic flap discs Council DL C POWERFLAP EXTREME is highly recommended.
The ceramic abrasive combined with the presence of cooling and lubricating additives ensure unrivalled grinding performance. Second pass Finishing the surface with velcro discs mounted on a roto-orbital sander. The most suitable choice are the DV G VSM KK772K agglomerated abrasive cloth velcro discs: the agglomerated construction ensures a consistent finish and a much longer lifetime than conventional abrasives. These discs are available in grits from P80 to P1200: how far to go with the finish and the number of passes depends on the degree of finish required. If the next step is a chrome treatment, a final pass with a P320/P400 grit is sufficient. If, on the other hand, the next step is polishing with abrasive pastes, a final pass with very fine grit velcro discs (P800 or even P1200) is appropriate to make polishing easier and faster Third step Polishing
The choice of tool varies depending on the size of the workpiece and the power tools available. If you have a bench grinder/polisher at your disposal, the choice will fall on the DT C or DT M quilted cotton or sisal/cotton discs.
If you only have an angle grinder at your disposal, then DL W felt flap discs or DC F conical felt discs are the most appropriate choice.
If the random orbital sander is also to be used for the final polishing step, then DF V felt flap discs can be used. All this should be accompanied by the appropriate PA L abrasive paste: white paste is ideal for an initial roughing pass, while for final mirror polishing the correct choice is blue paste.