Stainless Steel - Polished (post production)

At a request I have polished two of my rings after the manufacturing polishing process. It just goes to show that the Stainless Steel material is very nice for jewelry with a bit of extra effort (about 1 hour per ring).

Ring - With Balls


Polished during the manufacturing


PPP Post Production Polishing


Ring - Crown


Polished during the manufacturing


PPP

Obviously, a bigger and easier to reach surface on the object will give you a better result.

Very nice! But an hour a ring, wow.

That extra polishing made it look extra good! There's got to be an easier way, tho.

An hour per ring is not that bad. When I make silver or gold rings it also takes me between 1 and 2 hours to do the final polishing.

As this steel is much harder and rougher I was pretty happy with 1 hour.

I did this the classical way:
1. rough sanding (machine)
2. fine sanding (by hand)
3. pre-polishing (again machine)
4. final high gloss polishing (machine)

Although with step 4 you don't get the real high gloss like you get with silver or gold. Maybe I don't have the right polishing material/fat for this kind of steel. I will look into that.

I think the only thing that would make this process better/easier would be a higher resolution print. And that will come, I have no doubt.

The second one especially looks beautiful - great work! I tried grinding the pieces I had a little, and was pleasantly surprised how easily it ground. Mine were a bit fiddly though, and I don't have any special cutting stuff, so my results were uninspiring. I just used a grinding wheel in a dremel. Do you use files for the hand part, or paper/cloth?

Thanks for sharing!

Thanks for this post -- very valuable. Would you mind sharing the technical details -- like, what exact grade/brand of sandpaper, which machine?

OK first of all I have the use of a proper goldsmith workplace. That is were I make my silver and gold jewelry.

For the rough sanding I used a professional version of a Dremel. Basically this is a hanging motor with a flexible neck in which you attach the bits. Another added advantage is that you have a foot pedal to smoothly change the speed with which the bit is rotating. This gives extra control. I have used several bits from diamond coated to ceramic to sandpaper bits. This kind of depends which part of the ring you want to attack.

For the second part I always use a file around which I wrap the sanding paper. Usually of a fine grade (between grit 200 and 300). Also never throw out old pieces (up to a point). I find that used sandpaper gives you a better result without scratching the surface as much as new paper. So for these rings I have no idea what I used. It was a piece that just felt right.

For the pre-polishing I use a polishing machine with a brush head.

Something like the picture above.
I use a pre-polish paste that still has some sanding qualities. Dialux Vornex.

For the final polishing I used the same machine but now with a large felt disk and Dialux Gris as paste.

Just to clarify.

The photo's are taken at different times. But the before and after picture is taken from the same ring.

Nice work! gives me more confidence about ordering in SS myself

Thank you so much for sharing and explaining how you did it!

Joris

Thanks for sharing these details. It's ok to say, "Hey, I'm an artisan, a lot of what I do is not something you can buy at a store." The bits about the used sandpaper are particularly helpful. All the help is appreciated!

Mahalo for the great info and pics.

Is there a shrinkage factor going from the 3D model to stainless steel and then post processing?

Yes there is. If you want to get rid off all the little dents it will probably cost you about 0.1 - 0.3mm. This is also the reason why I don't do the inside of the rings (or just very roughly). You want to keep the right size.

3M manufacturing makes a special wet/dry finishing paper called MicroGrit. Other manufacturers probably produce something similar. It is available down to VERY fine grits like 2000g! The backing is plastic, it is very durable and works very well on all metals. Also, there are many diamond based abrasives that work extremely fast on hard materials like stainless steel. These cost more but the time savings often justifies the cost. If you have a rotary tool like a Dremel or a flex shaft you can use small felt wheels with various metal finishing compounds. These come in stick form. World wide you can look for products known as "Emery" "Tripoli" or "Diamond White" these are coarser compounds with a noticeable cutting action. Final polish on stainless is usually done with "White Rouge". Or spend a few bucks and use diamond paste compounds.

Also there are silicone rubber based polishing wheels. These small wheels are impregnated with various abrasives. Available from coarse to extremely fine. The coarser wheels have a distinct cutting action. The finest grits can produce mirror finish.

Just keep in mind no matter what system you use, you will need to do fine finishing in several steps. If you jump from 200g to a "polishing" wheel it will leave scratch marks that just won't go away. The rule of thumb for polishing metal is not coarser than a 600 grit finish before final polishing starts. At a minimum I 'd go from 200g - 400g - 600g or even to 800g before using polishing compounds.

No way around it polishing is laborious but if you take care in developing a system you can optimize your time. OHH, WEAR A DECENT DUST MASK!

-G

Super-useful! Exactly the kind of detail that I need. Cheers.

OK probably I am just cheap that I am using used paper

GlenG thanks, I wil give MicroGrit a try.

Actually! The 3M abrasive is called "MicroFine". There is another similar product called "MicroGrit" by another manufacturer. Hobby/Modeling suppliers are a good source for these type materials.
-G

How about sand blasting?

Bryson79,
I would be very interesed to find out what sand blasting would do to SS. Has anyone tried this?

Sand blasting eh?
Lots of variables here in terms of equipment and blasting media.
None will actually polish metal. As the name implies, blasting is an impact process with a distinct peening effect. All blast media produce some level of a matting effect. Glass beads or Zircon beads produce a smooth satin surface. Which feels nice to the touch and can look very nice too. Sometimes you can mask off some polished areas then bead blast other areas for contrast. Coarser medias, like silicon carbide or aluminum oxide have a distinct cutting action and will leave surfaces rough to the touch and dead flat in color. This is great for preparing surfaces when you intend to paint or glue parts together but it ain't real attractive otherwise. There are other much finer and softer medias like corn cob, walnut shells, even cornstarch. These media can be used for a burnishing effect on previously polished surfaces.

The pre-polished surfaces provided on some shapeways parts are put through a barrel finishing process. This is similar to a "rock tumbler" where batches of parts are sealed up in a rubber lined barrel along with various abrasive medias. The barrel is rotated for a length of time and the rough places become smooth. This is repeated in several steps, each barrel containing finer abrasive media. Presto, polished parts! The only problem is that these media can not reach into deeply fissured surfaces and tight corners. really the only way to do this is by hand. A rotary tool really helps but still, it is time consuming filthy work. It's one of the reasons i gave up being a goldsmith!