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High Finish


#1

Greetings, I need to put a mirror like finish on a piece of 24g
sterling 2x6 inches. I sanded with 600 paper until no scratches were
visible and then buffed with red rouge. The metal shines but under
close examination a bunch of pits are visible. How do you get a flat
mirror finish?

My instructor said he once returned a batch of silver to a supplier
as there were tiny but visible imperfections on the surface of the
silver that were almost impossible to remove.

Is this a supplier rolling mill produced problem?

Thanks,
Bill in Vista


#2

Hi Bill- What kind of buffing wheel are you using-I’ve gotten a
really high mirror finish - after polishing with rouge on a cotton
wheel and then with a leather wheel and “Fabuluster”- a white polish
in tube form as the final polish. I’ve used this on brass, nickel
and sterling.

Margaret from the Vista club.


#3

24 gage is pretty thin but you still left out a step or two in the
finishing department. There are now finer grades of sandpaper and
that might help. You also jumped to the rouge finish without using
some sort of tripoli. tripoli removes some metal as well as leaving a
low polish and it might be enough to get rid of your pits. You could
then use the rouge or Zam. Marilyn Smith


#4

Bill, What you describe seems to be a 2-step process – sanding with
600g then polishing with red rouge. To get a true mirror-like high
shine requires several more steps than that. Here’s what I do (in
order), for example:

Sanding (each grit gets sanded fully in one direction, then turned
and sanded fully at a 90-degree angle to the first sanding)

220 grit
330 grit
400 grit
500 grit
600 or crocus

At this point, your metal should be very smooth and free of any
pitting, unevenness, or scratches. If the metal was in really good
shape to start with, I might skip the 330 and 500 and go straight
from 220 --> 400 --> crocus. But if I had any pitting or rolling
mill imperfections, I would do the whole thing.

Buffing (each pass should be very thorough and as multi-directional
as you can make it)

Tripoli with a medium-hard buff
White diamond with a softer buff
Red Rouge with a very soft unstitched muslin buff or chamios

By skipping all of the coarse steps, you’re never reducing the
imperfections in the metal that the more coarse abrasives or polishes
would remove. A 600g paper, for example, doesn’t have the cutting
power necessary to remove pitting or deeper scratches. Likewise,
skipping straight to rouge (while I know that some people do that)
doesn’t take advantage of the excellent cutting and polishing power
of tripoli and white diamond. To get a really good finish, don’t
skimp on the steps.

It seems like a lot of work – and it is – but your finish will be
exactly as you want it, and your work will look truly professional.
It doesn’t take as long as you might think, either, because you’ve
done most of the work using the coarser grits. By the time you get
to the crocus or the red rouge steps, it goes quite quickly.

Have fun! Karen Goeller @Karen_Goeller

P.S. - By the way, even if I’m going for a satin/matte finish, I
follow the same steps, but usually only go to white diamond in the
polishing stage. On occasion, I’ve gone to red rouge and then done a
satin finish, when I wanted the piece to be ultra-smooth.


#5

Bill, There is an excellent article in this months edition of Bench
magazine that is just about the best I’ve read on the subject of
polishing. To anyone never formally trained on the art of polishing
I have this advice; get it, read it and apply it.

However, that said, I must also add this. All commercially
available sheet today is made with continuous cast technology. The
melted metal is forced through a die and then immediately rolled out
to the thickness needed. It comes out mirror finished and
beautiful. note I have never seen these machines but have had the
technicians from Hoover and Stuller both describe them to me when I
was facing a similar problem polishing their sheet. If I am
remembering anything erroneously feel free to correct me.

The problems that occur as I see it are two. First, after this
beautiful material comes out of the machine it is stacked piece upon
piece and it gets all scratched up. Back many years ago I remember
that companies used to put easily removable plastic coatings on the
sheet to keep it from getting marred, but that practice, sadly has
ended. So it is left up to us jewelers to polish out their
scratches. It really steams me when I think about it so let’s move
on.

The second problem is that just under that layer of mirror finish
you have a very large crystal structure due to the fact that it is
rolled only once through the mill. This does allow for small grain
irregularities to become large problems, especially if the sheet is
used in a raw form that is not manipulated, i.e. deformed, bent,
forged or rolled. note this is why many jewelers rarely notice
the problem, most of us deform the metal at least a little bit
before polishing it. Any deformation will cause the crystal
structure/grain boundaries to tighten up. This is what causes work
hardening and also makes for a better polishing surface. If you
just try to polish the sheet straight from the supplier you will
have to deal with this large grain structure and almost no amount of
presanding will do any good.

The only solution I have come up with is to spend a good deal of
time at the polishing wheel. If there are any real large scratches
that won’t come off with tripoli or whatever cutting compound you
use then definitely do some sanding to equalize the surface. Then
go over the piece with your cutting compound always making sure you
don’t continue in one direction too long. Turn the sheet in a
circular manner to avoid going in one direction. This is especially
important when rouge polishing as the pits (and very often
irregularities in the grain structure) will cause a build up of
compound that will cause drag marks. These are really time
consuming to remove and the only way to remove them is to go at the
sheet in that circular motion. I use cotton gloves (one pair for
tripoli and a different pair for every different type of rouge) as I
hold the sheet so I don’t mar it with my fingers or the excess
polishing compound that sticks to the grease on my fingers.

One other possible alternative is to buy sheet a little thicker than
you need and roll it down to reduce the grain size. I haven’t had
to do this type of polishing since I got my new Durston roller so I
don’t know by experience that this works; I’m just going by the
theory of the thing.

Hope this helps,
Larry Seiger
www.lshancock.com


#6

Hello Bill; You’ve received some very good advice on finishing
already,so I’ll try not to duplicate anything.I wanted to mention
something that I use quite often in my finishing steps. After emery
paper(s),I will often go to at least one to two grades of steel
wool,#0-#00-#000-#0000. #0000 is almost as soft as a cotton ball,very
very fine.I then always go to brown tripoli which still cuts as well
as polishes.I finalize with either Zam,Fabuluster,or one of the
rouges.Always after one of the polishing compounds,I clean the piece
so as not to have any of it’s residue left to contaminate the next
compound.HTH, John Barton


#7

Thanks all for the responses.

I have sanded with 600 again

Then 1200
Then 2000
Then 4/0

Next is tripoli, zam and rouge with washing in hot water, detergent
and a touch of ammonia between each polish.

The finish so far looks good and has taken on a light shine. By eye
it seems the dimples are gone along with the superficial scratches.

This is a commissioned pair of earrings. Originally the silver had a
hammered texture throughout then it was changed to ‘just’ plain
polished silver. Being rather large with only folding as specified by
the customer any mark on the surface will show. Customer also
specified the material thickness. Actually the entire design was
dictated.

Once delivery is made, I wonder how long the finish will last.
Received a pair to fix yesterday and the lady had to dump her
handbag to find the loose earrings in the bottom under her keys,
telephone and loose change.

Bill in Vista