Stainless finishes

[Tony]

howdy all.
i've been doing more and more work in stainless steel lately.. mostly sheetstock.

was wondering, what kind of finishes can I get for stainless?

how do I get stainless super shiny? i've tried my finest grit flapwheel and even some lapping compound, but I still see scratch marks. shiny for sure, but scratchy.

how about heat-generated colors? can I get a rainbow effect and buff it somehow? seal it? wax it?

anyone out there with cosmetic stainless experience?

oh oh how about *SATIN* ??

-tony

[webowser]

Type 304 & 316 Stainless steel sheet can be bought with a few different finishes. There is what is called 2B which is smooth and shiney, but kind of dull gray. I believe it is what you get if you don't request a polished finish. Then there are various grades of polish, up to #4 I believe, which many people refer to as brushed. Stainless steel kitchen appliances and building elevators are mostly #3 & #4 polish. Then there is mirror polish, which is exactly what its name implies. It is difficult to find mirror polished stainless in less than about 16 ga. because the process cause lighter gauges to ripple so the polished sheets aren't flat. If you plan to make something and then try to mirror polish it, start with 2B material. It doesn't have the scratches in it that the polished sheets do. You can mirror polish stainless with a cotton buffing wheel and polishing rouge, BUT highly polished 300 series stainless surfaces are very fragile. They are very easily scratched.

[CCWKen]

Can't help ya with the other finishes but for a shiny finish, it has to be polished. I restore lots of SS trim for cars. Depending on how bad the scratches, I use 400 and 600 grit on a DA sander. After that drop to 1000. Finish up on a buffer with some white and SS compounds.

David (ibewgypsy) used to have some polished SS sheet. Maybe he will devulge his source or sell some pieces.

[WJHartson]

I don't have any experience with rolling stainless steel but do with aluminum but I am pretty sure that the same things apply. I have polished stainless to a mirror finish as others have said.

With aluminum, the finish is produced during the rolling process including the mirror finish. The sheet will take the finish that is on the rolls. Bright sheet is rolled with super finished rolls. The rolls are like mirrors and the sheet will have the same appearance.

Check with your supplier and I think that they can get anything that you might want including embossed sheet.

Joe

[Tony]

mostly I'd be happy successfully taking out the work marks.. welding discoloration, bringing ground weld beads to the same finish..

my SS welds, after grinding down, are super shiny.. the problem then is getting uniform shiny on the rest of the piece.

not to mention my slip roller, and brake, both leave (sometime long) marks on the work.

and it would be nice to offer the stainless in different finishes.

anyone know what "pickling" is? and how its done?

-tony

[WJHartson]

Pickling is cleaning a sheet of metal in an acid bath to remove all of the surface contaminents. Piping can be pickled to remove and clean the ID. Steel sheet is pickled prior to galvanizing.

If you are trying to work with bright sheet the sheet should be covered with some type of protective sheet. Most of the special finishes comes from the mill with a protective covering on at least one side. The equipment that you use to form the sheet must be clean and some cases the forming pieces should also be polished. You can try puting heave craft paper over the sheet to help protect it from being marked during the forming operations.

Hope this helps.

Joe

[This message has been edited by WJHartson (edited 06-29-2005).]

[Swarf&Sparks]

I do a bit of marine work, pleasure boat mainly, which means it's gotta be SHINY
316 SS hi-pol tube for the most part, TIG welded. I get a nice finish with a sisal mop on a 5" angle grinder and green compound. Any lapse of concentration will be expensive and possibly painful. Take care! For a real mirror finish, go to tripoli (rouge) after the green.

[ibewgypsie]

Really a no-brainer.. the more you rub it the slicker it gets.

go through the rouges, a flannel buff wheel. To start with apply red rouge onto the wheel and let it dry, use the tips of the wheel and it will throw sparks.. really.. Bury the part into the wheel hard and it cleans the rouge off.

The stainless sheet I have left? it was hotel mirrors.. Extreme polish.. plastic on both sides (discovered that while trying to spot weld it)

A scotchbrite pad does miracles at getting you to a satin finish. They make them with velcro to go onto a 4" grinder. Neato..

I used to make my tattoo machines from stainless. Love it, no chrome to peel, shiny...


Yeah.. shiny...

David

[aboard_epsilon]

If the scratches are deep you have to do preliminary work.

This is because to getting deep scratches out with a buffing wheel may cause uneven dents in the surface because you have to stay in one place for two long.
to get the finest and shinieist mirror finish:-

I recommend first you determin how deep the scratches are.
Then you use a grade of abbrasive wet-n-dry by hand or a with delta/detail sander that is just about right to remove these scratches......

It may be that you may have to go as rough as 100 grade.
If you do this then you have to remove the scratches caused by 100 grade .....so go onto 200.......then onto 400.....600.....
only then can you go onto the buffing wheel.

A lot of people just start strait out with the buffing wheel and wonder why it's not got an absulutely perfect blemish free surface.

The above hand sanding method is how to atchieve that mirror finish.......
You need lots of patience and time..if you havent got it ......forget it .

all the best..mark