Pickling, Rust Removal and Zinc Phosphate

Pickling | Rust Removal | Zinc Phosphating

Pickling
 
We frequently pickle new and old steel pipes, vessels and components for our engineering clientele.
 
The process involved in pickling is threefold:

  • First of all, the items are given a hot caustic soak and water-blast to remove all traces of grease, oil and other contaminants. 
     
  • Next, they are immersion pickled to remove mill scale and corrosion, leaving a clean white-steel substrate. 
     
  • And finally, a hot phosphate treatment undertaken to condition the surface and prevent corrosion.


We are able to accommodate pipes and componentry up to 6 metres in length, which is within the range of most customer’s requirements. 
 

Examples of items received for pickling:
Steel pipes Steel pipework
Steel tanks received for stripping and pickling Steel vessels

 

Rust Removal
 
Powerstrip Industries’ method of rust removal involves immersion of steelwork in our acid bath. The process can be quick or slower depending on the type and strength of acid and the amount of corrosion present on the article. Powerstrip prefers to use a 100% inhibited phosphoric acid base to pickle away all corrosion whilst leaving the clean steel untouched. This method can take slightly longer than others but has payback from a safety point of view in that all un-corroded metal remains unaffected by the pickling process. Acid dipping treatment is followed by a hot water-blast to remove all traces of the acid medium. 
  
Rust presenting on a steel panel Flaking corrosion on a steel body
A badly rust-pitted machine part A rusting bolt
Corrosion on a steel muffler  White zinc corrosion on an aluminium security door
Before and after:
Corrosion on a steel panel A like panel post-treatment - with rust removed and inhibited
A badly corroded steel wheel rim The same wheel rim after acid treatment

 

Zinc Phosphating 

Phosphating deposits a chemically bonded surface on steelwork to prevent flash rusting and to provide an appropriate pre-treatment for primer application, without any further preparation (such as sanding or blasting). This should not be taken as a substitute for a proper protective coating system but as a preparation for such.
 
Powerstrip’s phosphate bath is heated to aid the phosphating process and this also assists with the quick drying of steel items when they are removed from the bath.

Steel cabinet after zinc phosphating Steel panel after zinc phosphating
Steel fencing after zinc phosphating Steel car bonnet after zinc phosphating