Finishing Stainless Steel

[jyl]

Does anyone have experience finishing stainless steel? To get a satin surface, a food grade surface, a high polish surface, etc?

A bit of reading suggests it is simply a matter of putting the appropriate belt or pad or disc on one's sander or grinder, and going at it, being careful not to overheat and discolor the steel.

Is it that easy?

[Drbraunsr]

For 'graining' the SS a flapbrush is what the industrial folks use or a coarser grade convolute wheel. These products are also a bit more forgiving in the hands of a novice. A coated abrasive belt could work but wouldn't be my first choice. A Scotchbrite belt would work if a belt sander is your go-to tool, just run it on the slack.
3M and Standard Abrasives offer the best products.

[serene911]

Use a buffing wheel with various rouges to get a higher polish or mirror finish.

[nota]

the idea is buff away the steel surface leaving only the chrome
SS is not stainless unless the surface is buffed
scratches will rust

[jyl]

Thanks!

[red-beard]

Do not use a wire wheel. That will leave in bits of regular steel, which will rust. Scotch bright (nylon) pads are the way to go.

[Zeke]

^^^^ Convolute wheel AKA de-burring wheel. A bit pricey compared to a lot of wheel products.

[bkreigsr]

McMaster sells a hard rubber sponge-type, drill bit 4 inch disc for polishing ss.
I haven't used it yet on my muffler.
Bill K

[Bill Douglas]

As long as the area is not huge; I use a worn (not too scratchy) scotchbrite and soapy water. As mentioned don't hit it with anything that contains carbon steel.

[1990C4S]

Google the DeLorean problem...

DeLorean Restoration: Re-texturing the Stainless Steel

etc...

[bleucamaro]

I use Scotchbrite (red) with a D/A sander a bunch, but our tooling rarely requires a high polish.

If going for a higher polish, start with sand paper with a grit course enough to remove the blemish you need gone, then work finer until you get to the level of polish needed. IE, 120, 240, 400, 800, 1600, 2000. . .

Then go to polishing compound and highspeed buffer.

For small parts, I have a wire wheel and a polishing wheel in a pedestal grinder.

Question: What is the use of the material you're finishing? Is Polishing the answer, or should you be looking into passification?

[jyl]

Just furniture and workspace uses. The stuff either has an unattractive stainless finish or a battered stainless finish. Wanting to make it look nicer.

[Porchdog]

We do a ton a day or more of stainless in all finishes.

If you have someone nearby who does glass bead that could be your best option. Fast, easy, consistent and it looks good.

As the other guys said - if you need brushed, satin or polished it's a matter of quality abrasives in progressively finer finishes. Electropolish at the end will get you that "Mirror-bright" finish, but not cheap.

As for Scotch bright - if you are using much find the grey stuff that's made for stainless. It provides a nicer finish faster.

For passivation most people will want to send parts out. The point of passivation is to strip off the oxidation layer so that a cohesive oxidiation layer can form to protect the finish. The real challenge is cleaning before passivation - I usually insist on acid pickling first. If the is any free iron at the surface you will get rouging no matter what else you do.

You can do the passivation yourself with the commercial gell. The major trick is making sure the surface is clean first. Rinse with distilled water.

The company my son works for had enough problems with commercial passivation vendors that they had him set up their own passivation lines in two of their plants. They do a lot more stainless than we do.

We do most of our in-house passivation with a Cougartron now. As near as we can tell it is as effective as outside pickle and passivate, but we can do it in-house. Not cheap.