These brushes are used for pickling welds or aluminium welding processes. With the available fluids, you can also use for passivation and marking
For longer stands you should use in tube (PTFE) and keep the working end as short as possible
Carbon fiber brush/acid scrubbing brush to welds. You can use these brushes to erase tempered colors from the welding process of stainless steel V2A/V4A/AISI 206/AISI 304/AISI 316 or have been quenched and tempered
These brushes are produced for electrolytic pickling and use with mordants