Acid Finishing Stainless Steel???

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Acid finished, post welding, stainless steel sheet metal was mentioned in another post. Can anyone give more information about this? What is the process....What type of acid is used......best place to purchse acid..ThanksMiller TrailBlazer 251Miller HF-250-1Miller MaxStar 150 STLHyperTherm PowerMax 380 plasmaLincoln PowerMig 180Millermatic 252Miller Diversion 180
Reply:think your talking about stuff like this :  http://www.derustit.com/I've used there wonder gel, you brush it on & then rinse it off after 25-30 minutes & it removes all coloring & oxidation.miller 330a bp TIGmiller dynasty 200DX TIGmillermatic 185 MIGthermal dynamics cutmaster 101 plasma cuttersnap-on YA5550 plasma cutterhypertherm powermax 30 plasma cutterbaileigh CS225 cold sawetc....
Reply:Passivation is the process. I do not have the brand name. It was used at a tank manufacyurer / erection company. I believe it was based on a diluted nitric acid compound.
Reply:As said before, passivation is the name of the process, it is fairly dangerous stuff, i don't know the chemical composition i just use it. You need rubber gloves and eye protection, if it touches skin rinse with water quickly. You need a brush to put the stuff on, the brush must not have any metal  parts on it, only plastic or wood. The room temperature must be above 15-20 celsius, the stuff turns green when it's done, wash with a lot of water (again eye protection) and some scotchbrite.The ss might look stained after this process but it goes to it's regular look after a couple of days.You also may not want to inhale the vapours.--------------------------------------------------------------www.becmotors.nlyup, I quit welding.. joined welder anonymous
Reply:The passivation pastes are often hydroflouric acid based.  If you expect the material to withstand corrosion it is most important that the area be passivated.  Most larger welding supply houses stock the material.  To give you an idea of the strength of the acids used , it comes in a plastic container.  It will etch through glass.  There are citric acid based materials that are more friendly but not quite as effective.Last edited by lotechman; 12-13-2010 at 09:21 AM.
Reply:As mentioned, acid treating stainless steel is USUALLY a passivation process.  A pretty strong acid is used to dissolve off some of the surface iron and iron oxides (heat tint) as well as the earlier process steps to remove grease and oil as well as other surface contaminants (swarf, grit, etc).  The desired result is a clean and chromium-rich surface layer that then is more 'stainless'.http://en.wikipedia.org/wiki/PassivationPretty strong nitric acid is the acid I think of most for stainless steel passivation.  As with ALL strong acids, safety must be thought of and proper process steps and PPE and environmental controls used.  Cause the acid and acid fumes/vapors don't care if they are dissolving steel oxides or your skin or your lungs or your eyes.http://www.alleghenysurface.com/inde...FeFw5QodWhWl0ghttp://ptiindustries.com/index.cfm/p...FaVx5QodTzoM1Ahttp://www.alexandriametalfinishers....Fc9w5QodIiBVCghttp://www.kepcoinc.com/?page=servicespassivationre: hydrofluoric acid  Yes, hydrofluoric acid can dissolve glass.  That is one of its industrial (and craft) uses, to etch or 'frost' glass.  Could be one of the 'nastier' strong acids, as it also not only dissolves glass, but also skin, muscle, and bone.  But AFAIK, hydrofluoric acid is NOT a typical stainless steel pickling and/or passivation acid.http://en.wikipedia.org/wiki/Hydrofluoric_acidLast edited by MoonRise; 12-13-2010 at 10:00 AM.  The best laid schemes ... Gang oft agley ...