Experiencing issues with Phos-Kleen B rust remover and phosphating solution?

Experiencing issues with Phos-Kleen B rust remover and phosphating solution?

Tuesday 7 June 2022

Rustbuster Phos-Kleen B is a clear liquid containing a high grade of phosphoric acid and industrial soaps. Phosphoric acid is a very important product that has wide-range applications in different areas, such as the agricultural industry, food industry, medicine industry and so on. And in every industry phosphoric acid all plays the significant part.

In the automotive restoration sector, it is used as a light rust remover that doesn’t attack Iron but will dissolve rust whilst inhibiting the surface from flash rusting by leaving a thin layer of Zinc on the surface.

Phos-Kleen B (Phosphoric Acid blend) is a gentle acid to Iron unlike Phos-Kleen A (Hydrochloric Acid). This is worth keeping in mind when selecting the correct product for your project.

Phos-Kleen B works by applying to surface rust sparingly by brush, spray bottle or Scotch-Brite pad and allow time for the product to work and dry.

When the surface has thoroughly dried (ideally overnight) the metal will have a blue grey colour.


rusty surface not cleaned Phos B applied to surface uncleaned surface treated with phos kleen b
Un-prepared steel surface showing signs of loose rust
and surface contamination
Phos-Kleen B brushed on to the surface Pho-Kleen B dried on to the steel surface has disolved rust but showing some white powder


But what if the surface you are seeing has a white powder to it?


white powder showing after using phosphoric acid

Above you'll see the Phos-Kleen B has come into contact with some surface contaminates that has caused the white powder to appear


Phosphoric products only fully work when full wetting of the surface being treated is achieved, ie if you haven’t de-greased, removed salt and wire brushed before removing any dusts is un-likely the Phosphoric Acid is fully wetting the surface, these surface contaminates are stopping the Phosphoric from reaching the surface evenly.

Some metals will produce a white powdery layer when coated with Phosphoric acid if other contaminates are present, this powder can be simply washed away using Rustbuster Chlor-X and a scoth-brite pad.

How to stop this from happening?

Prior to any manual preparation here at Rustbuster HQ all metal is thoroughly washed using  de-greaser and Chlor-X salt remover, typically this is done with a high-pressure steam cleaner, once the chemicals have been given time to work, we wash again with fresh water. This process removes all possible surface contaminates that could stop and further treatment from working correctly.

If you are experiencing any problems with a Rustbuster product help is always available, please contact us.

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Rustbuster Ltd
Welland House
Cradge Bank
South Lincolnshire
PE11 3AN

01775 761 222


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