Electropolish Or Not To Electropolish?

All depends on how good a finish you need, blasting is quick but will leave a dull finish. Rubbing will take longer but will give a better finish, maybe use Scotch-brite pads instead of abrasive sheets. Autosol is a bright-work polish, it will make surfaces shiny but will not remove heavy discolouration or score marks.

Soak them in citric acid, or rub them with lemons.Keep rubbing them for a half an hour.

As in "I saw you using lemons" from Atlantic City?

sorry i missed 1 thing.

my goal is to remove iron particles from ss316L..do you think using pure c.acid or pure lemon juice do the job?

u did'nt say anything about using vinegar. vinegar has c acid and acetic acid

No, vinegar has acetic acid but not citric acid. The Latin word for vinegar is "acetum". That's where acetic acid gets its name.

If the particles are loose, ultrasonic cleaning will remove them. A dilute HCl dip should remove iron without affecting 316L. Citric acid will take a longish time to act.

No, citric acid, not acetic. I've used lemons to remove the mineral scale from metal, but just buy some and Google for a process you like. It won't over etch, so time isn't critical.

Never seen Atlantic City.

Forget electropolishing.

Today i got some one who does the hard chrome job. He used to remove some metals from other metals, through electro-polishing, in the past but has never worked on S.S.

He is ready to help me if I could bring him the formula for Citric acid. Now, should I go and buy C.acid and use it undiluted? or mix it with water? or else?

Alternatively, I'm thinking to use your method but with a vengeance; collect as much lemon juice as to soak all the stuff and let it be soaked for one full day, nothing added,no water or else, Then rub it and rinse. OR, OR..add some vinegar with high level % of C.acid in the lemon juice.

I've used vinegar with success to clean hard to clean stains in kitchen and wash room that also included some rusty stains.

waiting for your advice!!!

I'm not familiar with electropolishing, so I'm shooting in the dark! Your grits, 220, 240, & 300, sound too coarse. How shiny do you want the parts? How big are the parts? If a large area, you should investigate using an auto body polisher that paint shops use.

240 Grit made of silicone Carbide is mentioned at the British S.S association site which can produce a result of Ra <0.5 micron at the S.S surface.

I bead blast SS parts quite often. I rather like the satin type finish that it leaves. It's the most aggressive method of the bunch and would probably be the most time efficient as well. I would suggest blasting, then using the lemons if you want to improve the lustre and pick up any trace remnants of iron that may or may not remain, particularly if there are areas that the blasting couldn't reach properly. But blasting alone should do the trick.

are u saying that blasting alone can remove iron particles?

what should be the material? i can arrange for Silicone Carbide grit powder which is used in polishing belt.

I couldn't answer that with absolute certainty. I can tell you that I use blasting quite frequently on SS, for many aesthetic reasons... to get a uniform attractive finish, to remove various staining or scaling, to deburr or round out very sharp edges, etc. and I've always had satisfactory results.

By my way of thinking, it would stand to reason... given the various methods that have been suggested here, that if you blast it thoroughly, you will accomplish what you're trying to do. But if there is any doubt to that, if it was followed up with a moderate rub-down with citric acid (which is relatively simple and inexpensive to do and was another suggested method), that you could be doubly certain as to a proper job of removing the particles; and get it done rather quickly.

If blasting would be your preferred method, perhaps we could get some other opinions as to the validity of my idea. Perhaps someone will point out a flaw I haven't anticipated. But it's the way I would proceed if I had no one to ask.

I think that using the citric acid method alone would be a very slow process.

Do u blast newly made S.S apparatus, equipments to drive away Iron particles? do you have it scan through electron microscope or similar?

Most of the people believe to electropolish cause buffing or other mechanical means will bury further the iron particles.I guess blasting is another mechanical of the means.

If it's available, you might want to consider glass bead blasting instead of silicon carbide. Silicon carbide is extremely aggressive, and removes quite a bit of material very quickly. If not used properly, it can sometimes be difficult to get a completely uniform look. Glass bead allows more room for error, as it doesn't work as quickly.

The British S.S association has suggested Silicone Carbide to get the 0.5 micron Ra value. I have noticed one thing in this forum that people are suggesting there own idea rather than the idea having connection to the bonafide authorities in the field. Perhaps they are sharing there own experience. This is called the difference obetween books and practical life.

Lots of suggestions but we still don't know if these parts are large or small & if the cleaning is for the inside or outside surfaces so it's difficult to know if the suggestions are useful.

I'm with Nigh. Are these rollers for the sugar mill?

We have been dancing around without enough information.

Looks like you need mechanical smoothing/polishing followed by Passivation.

I'd suggest Citric Acid Passivation. The prepared solutions can be bought by the gallon, or take the suggestions offered above. Citric Acid is easy to dispose of compared to Nitric. Covered here often.

yes for cane...miniature...4x2 with 1 inch dia. shaft

the plates are 4x9 inch aprox.

rollers have not yet been touched except for the shaft making at the corners, but it will be better to treat the main surface which will be doing the job of pressing.

O.K...this one is about the roller surface treatment.

Should the surface be treated BEFORE serration or after?

I'm thinking to polish it with 220 grit, serrate, rinse with lemon juice to drive out all the possible contaminants present there before and after serration

Do knurling patterns on the surface of the rollers need to be passivate?

I want to use Carbide knurling tools but could not find any..so..will have to use steel tool which will leave iron particles on the surface

Passivation should be the LAST process.