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Hydrofluoric Cleaning Alternative

I am searching for a safer alternative to the hydrofluoric/nitric acid bath that we currently use in our chemclean line to clean and etch 304 stainless steel. Does anyone know of any alternative chemicals that can effectively remove heavy stains and heat-treat oxides? If not, is there any way to generate the HF in the tank, so as to eliminate the hazards of transporting and pouring the HF liquid?

Ross Hays
- West Burlington, Iowa, USA
2000

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1 of 2 simultaneous responses 2000

Ross:

I know of very successful vibratory finishing processes to remove heat treat residues and other heavy stains from Austenitic Stainless Steels, such as 304, 316 & 316L. These are active chemical processes that use Oxalic and citric acid ⇦this on eBay or Amazon [affil links] s mixtures or Sulfamic Acid with Fluoride that react the residues and stains to allow them to be easily abraded away. The processes are capable of producing surface finishes from matt surface to near mirror reflective fully refine surface. If applicable for your operation, I am available to further these discussions. Good luck.

Bill Boatright
Houghton International - Raleigh, North Carolina

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2 of 2 simultaneous responses There certainly is a safer method to get fluoride. Use ammonium bifluoride. It is a crystal. Once it is dissolved, the extreme danger is over as the fluoride level is down to an area that is not particularly any more hazardous than the nitric acid is.. Sorry, I do not have the conversion factor with me at this time.

James Watts
- Navarre, Florida
2000

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Ross:

We have a non-nitric, non-hydrofluoric method for cleaning and passivating chrome alloys. It is NOT citric acid based. I would be happy to do some parts for you to demonstrate its capabilities. Dan Weaver

Dan Weaver
- Toccoa, Georgia
2000