Stainless  Restora​tion Ltd

Metal Finishing and Surface Engineering Technologies

SRL Technical Library

PICKLING AND PASSIVATION TROUBLESHOOTING  During, following or indeed before the cleaning operation all sorts of strange things can occur as a result of the chemicals used. Our technical library gives a variety of examples that SRL has encountered along its way. This list is by no means complete - these pages will be continually updated as we/you experience other strange phenomena.

Ink & Paint Marks

Identification

Pickling Ink and Paint Marks

Obvious ink or paint marks on the surface often put their for identification purposes or instruction during fabrication. These serve little if no purpose once the job is built.

Possible Detriment

Apart from the fact that the surface will look unsightly and indeed, if a food/pharmaceutical bearing surface it will look unhygienic. There is documented evidence from research done in Sweden that corrosion can set-in between the ink/paint and the stainless steel surface, crevice corrosion. It is important also that if you insist on using marker pens and paints that you use those that are "chloride free".

Other problems can occur also. If the ink/paint is not removed before pickling then it is likely that the marked area will pickle (etch) at a slower rate than the rest of the surface adjacent, resulting in a "shadow" remaining often in the shape of the mark. This is rather like wearing your wrist watch in the sun and taking it off after a few hours you will have a "shadow" outline of where your wrist watch has been...this is then difficult to remove since you can't play catch-up since pickling is a controlled corrosion which is even across the surface.

Solution

Solution: Remove the ink or paint with solvents such as Thinners, Toluene, MEK, Acetone or if stubborn use paint stripper gel. care must be taken if paint stripper is used since it does often contain chlorides in high portions. See product list below.

Method: Wipe the solvents across the offending area using a clean dry cloth.

Warning: when using a paint stripper(s) area must be washed down with HP water to ensure the complete removal of the product. SRL's paint stripper gels contain methylene dichloride that will pit the surface if allowed to remain.

Products  Available

Pickling Products

Cleaning Products

Technical Notes

It is important to follow the instruction given for each individual product used and the advice given in the "product application data sheets" available on line in the product section of SRL Chemical and Analytical Services Ltd.

Information given in this page may be subject to alteration without notice.

Care has been taken to ensure that the contents of this publication are accurate but SRL Site Services Ltd do not accept responsibility for errors or for information that is found to be misleading.

Suggestions for, or descriptions of, the end use or application of products or methods of working are for information only and the company accept no liability in respect thereof.

Before using products supplied or manufactured by the company the customer should be satisfied of their suitability.

If further assistance is required, we have access to extensive research facilities, we will often be willing to help.

Stainless Restoration Ltd, Adamsons Industrial Estate, Hyde SK14 1EE

Stainless Restoration Ltd offer an Electropolishing service to the stainless steel fabrication/manufacturing industry at its newly refurbished fully automated Electropolishing plant at Hyde Manchester.