Burnishing an electrical contact - GIF

[desbromilow]

I don't know if burnishing is the right term to use there since the tool being used is a fibreglass pen - basically a tight bundle of fibreglass strands all being used "end-on" as an abrasive to clean contamination off the contact. I consider it more along the lines of cleaning, whereas I always thought burnishing was smoothing by imprinting the metal surface with a hardened smooth surface (eg agate, hardened polished tool steel)

those pens are fairly cheap, and offer the replaceable fibreglass insert tip, or a brass brush tip - as the tip gets worn away you advance more to stick out and get used (like those kids twistup pens) In Australia we buy them from RS when we need to restock.