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Polishing or finishing stainless


#1

I am making some jewelry pieces by forging/bending small stainless
industrial objects. Heating them in the forge damages the polished
finish, and I am trying to find the best way to bring back a polished
finish. Not necessarily a mirror finish, but shiny. My thoughts were
to use a vibratory tumbler to make the process faster, but I am
having a hard time finding out enough to make a good choice. I don’t
want to spend a fortune on an industrial tumbler since this project
is still experimental. Some of the smaller, more affordable tumblers
state that steel shot can’t be used. I assumed (again I don’t know
for sure) that steel shot or pins would be necessary to polish
something as tough as stainless. Some of the tumblers I’ve seen in
the price range I’m considering ($200-$350) have very poor reviews
mentioning things like they vibrate themselves apart. Does anyone
have suggestions as to reliable tumblers and exactly what media and
media sequence are necessary to polish stainless? Or is this
unrealistic and I need to polish each piece separately with my
Dremel, buffs and polishing medium? Would a rock tumbler (much
cheaper) be a better choice? If so, how long would it take and what
media would I need? My son suggested getting a paint shaker and
putting the pieces and media in paint cans. The shakers are a lot
cheaper, but would this work? I would be doing rings, bracelets and
neck pieces.

Thanks
Linda Holmes-Rubin


#2

This is an interesting question, because what happens in the forge is
that you are changing the metal surface to a thick layer of chromium,
nickel and iron oxides.

So what you want to do in fact is remove this surface layer.

Steel shot or pins wont do this as they do not grind away the metal
surface, they burnish it.

so your going to need to go down the stone barrelling route, using
an abrasive grit in with ceramic pins in the liquid medium.

This will dictate the type of barrel, most probably rubber lined to
prevent it wearing away as fast as the objects your tumbling.

Some rock tumbling can take days. The only quick way is to have a
grit blasting cabinet with glove ports a 90 psi @ 10 cfm
compressor,120 ali oxide grit etc.

Your paint shaker would do but it would wear through faster than
removing the oxide layer…

Check out your local rock club as they do this sort of thing.
Someone might just offer to run a trial for you.

As for size, at least 9in in diaby 5 in wide. the bigger the better.

Once youve the oxide layer off, then use the steel pins to burnish
ifou want a shiny, shiny, finish…

However!!

one of the product range ive made “the dark ages” uses just this
coloration. I use stainless steel assembled and joined with TIG
using argon, I also use this TIG tech to fuse the sheared edges into
a smooth round finish. No need to file up at all!!.

Then polished, then coloured in a neutral propane flame from a 2in
dia burner.

beautiful browns and purples and amber coloured oxide film. Never
wears off.

sells very well.


#3

why not go to a home store and by some cheap compound for stainless
steel? Its available in a tube use a felt or leather dremel bob, or
wheels and keep those seperated from any compounds, charged wheels,
bits, etc.

you use for any other metal. A Dremel will do it as will a Harbour
freight motor with a 3" grinder and polishing wheel charged with
various compounds for steel and ferrous metals (the home store
packages tell you on the labels what they are for). And if you need
to grind the steel to add a texture, or “erase” something you didn’t
want and re-polish the single motor with 2 arbours will do the trick
faster if they are larger pieces where the dremel is great for small
work. (always keep those felt, chamois, or leather 3" wheels
separated from those you use with silver or gold). Tumblers are a
good investment but i would never use the same one for ferrous and
non-ferrous metals and not knowing the size of your work. I can’t
recommend one over another. A dual small tumbler may be an answer
here too as one could be for precious and the other non-precious
metals running different media in them if they are small parts/work.
Vibratory tumblers sold in harbour freight or hardware stores with
their impregnated plastic or ceramic or even walnut husk abrasive
media (that you can add a bit of compound to charge it for a good
pre-polish or at least brightening, if not a mirror finish with
graduated abrasive grits used in cleaned out barrels of the same
tumbler) are great with abrasive media for removing rust from steel
and in jewelllery for deburring more than polishing.

I don’t understand the paint can shaker idea your son has is too
fast and not appropriate even if you put it on a controllable
rheostat to turn down the vibration. It sounds like a harbor freight
tumbler is the way to go on a budget to see if you get the results
you want. Why spend the money using stainless mixed shot with
burnishing compoiunds to charge it if you are using stainless and
don’t want a high polish. Try with the cheaper variety first. the
types that run liquids (they have hoses for draining) and will do the
job, outdoors- the one problem is they are noisy as they are intended
for removing rust and oxidation from heavier items like tooling, than
metal work- again, I don’t know the size of your work. But the
average dual drum tumbler takes a very short time with stainless shot
or ceramic mixed shot and a liquid compound in an hour on soft metals
and perhaps up to 2 for steel and other ferrous metals (I like a
product called sunsheen, but there are many on the market. Even a bit
of water soluble stick type rouges will work -except limit that to
those forr ferrous metals in your case. If you get a small dual drum
tumbler dedicate one drum for stainless steel use only or buy a
single small tumbler that only is used for ferrous metals. I
wouldn’t spend a lot until you try both hand working it with a dremel
and some inexpensive compound (try and buy a water soluble type for
easier clean-up) and then if it isn’t working for you graduate to a
tumbler, then a vibratory with a liquid accepting barrel so it’s not
just a noisy rust remover!.If I knew the size of your work it would
help…

You can also build your own tumblers but at 30 bucks the harbour
freight ones work great for a first time experiment. Like my
favourite salesman tells me when you buy anything from them run it at
full load for at least 24 hours to make sure there aren’t any
problems, give it a rest and rerun it. You have a limited time to
make returns there (as with many vendors now) so you need to test it
thoroughly- the first sign of problems exchange it! Another point, if
you aren’t making large production runs of parts, then a small
tumbler will probably suffice. rer


#4

Todd Hawkinson is the man to ask about this :slight_smile:


#5

Hello Ted

I have used stainless steel and like you say after the forge you
have a hard oxide layer to deal with. The same happens to Titanium
which I have forged in the blacksmiths forge, it moves beautifully
when red hot but is rigid when cold. However you are left with this
hard oxide layer. I have never barrel polished SS and find your
suggestions very interesting. After the usual grades of emery paper I
polish with a proprietary SS polishers compound, firstly Carbrax
Compo for the rough work, then finishing with white Hi Fin on a
stitched mop which is a bit harder. I now use Hi Fin, which I think
is a tin oxide compo, for polishing all my Gold and Platinum work so
much cleaner and faster than rouge.

Cheers
Hamish


#6

I have a small bar of polish for stainless if you like to try.

Andy The Tool Guy


#7

I work with stainless steel. I always use water as cooling. I use
sandpaper for pre polishing on rubber wheel and also with water for
cooling. Polishing gloss paste I use green and then to final gloss
rouge brush jeans. Carlos


#8

Hi Linda -

Yes you can finish stainless with mass finishing. It’s how all the
commercial stainless is finished.

The process is straight-forward. First remove the scale formed from
heating with an aggressive abrasive media, then refine the surface
with a medium abrasive media. Follow those steps with burnishing with
steel.

What you have been seeing about machines disintegrating while
running steel is accurate. If you would use a vibratory tumbler for
steel, it needs to be rated for steel and to be effective needs to
have sufficient steel in the bowl to roll and thus to burnish your
work. There are vibratory machines that work with steel, the AV25SS
is one but to use it requires a lot of expensive steel - 50 pounds of
steel at about $700+. And the machine is $550.

If you want to buy something, I’d recommend the AV25SS but only for
abrasive media. The machine is well engineered, mine has run for the
better part of 20 years. It’s a real workhorse. There are lots of
suppliers of machines and media, I’ve used Rio Grande for years -
they are close and shipping is quick and cheap - and that is the
stuff I know. What ever supplier is close to you will have good stuff
too.

For scale removal and general clean-up on steel, use ceramic
aluminum oxide media for your first step - rio number 339416. The use
the clean cut media - a synthetic quartz number 339408. How far you
go with clean-up will depend on how good you want the final finish.
You can go one step farther with the fine clean-cut abrasive. To get
a shine, economically, I’d use a rotary tumbler and mixed stainless
steel shot. The rotaries require far less steel and, in my 20 years
experience, are really durable.

All that being said - this isn’t a cheap process. Two things that
might help you get on the right path, first get “Tumble Finishing for
Handmade Jewelry” - a book I wrote that will help you understand the
process, then you might want to try and convince one of the tumbler
suppliers to run samples for you. The book will help you with
terminology and techniques so you can talk knowledgeably with the
tech support folks. Book available from Rio Grande, Otto Frei, and
Gesswein.

Mass finishing is a somewhat technical subject and rife with
misIt is extremely useful, especially in a small shop.
It’s like having another employee, but you only have to pay them
once. It can do pre-finishing, texturing, cleaning of all kinds of
stuff - even beach shells. It removes very little material, far less
than hand finishing, thus saving real costs of precious metal. It
preserves detail. And it is absolutely repeatable. I first got
interested in the process to avoid the dust and dangers of hand
finishing. I’ve never looked back.

If I can help further, please contact me directly. I’ll gladly help
if I can.

Judy Hoch


#9

Its a joy to hear that there is someone else that forges metal!!.

I can tell your in the UK as you use Cannings polishing compounds. I
use these as well, and can endorse the use of hyfin.

Tho for polishing titanium, a pre cutting with a flexible silicon
carbide wheel is essential.

From interest, my titanium bowls ae all cold forged. Polished then
fire oxidised.


#10

Thanks so much for the I wonder how much the abrasive
grit will remove to get the oxide layer off. There are various ID
marks that I want to preserve on the pieces. But as a first step, a
sand blast cabinet might be a good idea. Most of my work is not
jewelry, its decorative blacksmithing and metal work. So I have been
considering getting a sand blast set up anyway. Then maybe a rock
tumbler and steel pins to put some polish on it.

I knew the Orchid group would have some answers for me–thanks all
of you!

Linda