Pickling and passivation

Nitty-Gritty’s Clinox line, born for weld cleaning on stainless steel, is the most complete, most advanced range of pickling machines available today in the world. By drawing on their inverter technology, all Clinox machines can control the fl ow of current. This ensures optimal working conditions, on any type of surface, and avoids irreparable damage to the stainless steel.

All Clinox machines ensure the best result without wasting time because they can both pickle and passivate. Pickling means removing ferric oxide – the typical blue or bronze-brown colour – thus protecting the steel’s shiny look and avoiding corrosion. Passivation is the restoration of the chromium oxide layer that protects the stainless steel from corrosion.


The process of weld polishing needs particular care when treating steel with special fi nishing. There are mainly two reasons that make the polishing process so relevant: the need to uniform the surface of the stainless steel after the pickling, and the need to favour and improve the process of steel passivation.


Neutralization stops the action of the pickling agent, neutralizing its effects and avoiding rings. To do this, the Inox Fit liquid is sprayed after pickling and polishing. This liquid has higher surface tension than water and guarantees a perfect finishing on every kind of steel and on the whole surface.

No pitting corrosion

If we carry out the weld pickling operations by using a carbon fibre brush, built on a trasformer-integrated machine – technologically unable to manage the short-circuits occurring during the process – we expose the stainless steel that we are treating to the phenomenon of micropitting: micro-holes, micro-wounds that avoid the complete and proper passivation of the treated surface. This, in fact, undermines the resistance of the steel, which can be exposed to that particular type of corrosion named as pitting corrosion.

Thanks to the inverter technology of the Nitty-Gritty Clinox range of products, the machine is run by a microprocessor which intercepts and cuts the short-circuit, thus avoiding any possible phenomenon of micropitting. As such, we ensure the proper stainless steel passivation, and avoid any corrosion or micropitting, even for those manufacts working under hard environmental conditions (marine, food, pharmaceutical, medical sectors).

There is always a difference between Nitty Gritty Clinox machines and the other machines: even when this difference is invisible to the eye.

Welding example (before and after)