passivation of 300 series stainless steel

[DonHolte]

Does anyone have experience with "WEDAC", "Citrisurf", or other passivation chemicals, for use in field construction?

If so, what are the pros, cons, and watch-outs?

Thanks,
Don

 

[unclesyd]

“Wedac” is H3PO4 based Metal Cleaner that can be used as wash primer for painting. It is a very good product for it's intended use but not a very good passivator for S/S. It can actually leave a PO4 film on S/S under proper conditions that will enhance atmospheric corrosion resistance.

“Citrisurf” is Citric Acid based product that allows you to passivate S/S without the use of Nitric. The pitch is that it replaces QQ-P-35(a passivation procedure using nitric acid) with ASTM A967
which allows either HNO3 or Citric Acid. For very corrosive atmospheres it still takes HNO3 passivation to be effective. Citric acid based cleaners can be quite effective in some cleaning application but I’ve heard of Painting problems that required a switch to a H3PO4 based material .

Can you post a little more information as to what you are trying to accomplish?

 

[DonHolte]

unclesyd,

We are evaluating these products for post-weld heat tint removal, and passive layer restoration; both with and without mechanical removal.

Don

 

[ozandincel]

contact

http://www.russamer.com

 

[unclesyd]

We used the Blue Away on Stainless Steel welds and if needed the Simichrome Polish.

http://www.competitionchemicals.com