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[Tool Time] Polishing Part 3


#1

Dear Tool Timers,

Well here goes. Polishing supplies. Yes, there are dozens of choices.
And you can polish a total piece with one or two buffs. Right at
your bench! This piece will be really shiney and your face will be
really full of compound. Now blow your nose and recycle! All the
valuable material may go right into the trash. This is like the
jewelry I see walking down the midway at our state fair (by the way
the Minnesot State Fair is the second largest in the USA). Mostly like
REAL shiney Harley Davidson jewelry, skulls with stones in the eyes,
those little pointed horns and happy face pendants. Black antique and
shiney metal WOW! No offense intended to these sources. Well, yea
really, but I confess, I have made Harley Davidson earrings. It was
long ago when I was a young child. Some people can be hypnotized in a
room full of bright lights too. Can you tell I like properly polished
jewelry?

I will describe a specific and basic start up kit. These supplies
should last and be added to with time and various other polishing
projects. The process I describe should work in any size shop.

Talking about this without the ability to show anything will be a bit
of a challenge. First I want to describe the item I will polish so
everyone can visualize what I’m talking about. I also have some terms
I use in describing the different parts of a ring. I want to challenge
everyone’s power of imagination here. I hope you all can place your
own jewelry in here some where. Keep in mind you are using time and
materials in this process. You have to spend some money to make money
in this case.

This item will be a cast ring. It is a man’s flat top signet ring.
The top is approximately 15 mm X 12 mm oval shaped. Everyone know
where the top of the ring is. This is a flat surface. This flat
surface has a sharp edge where it stops. Opposite the top is the spru
location, at the bottom, which is the palm side of the ring. Looking
at the ring from a side view, down and next to the top is the shoulder
of the ring. A triangle shaped keltic knot will be recessed in the
center of this shoulder towards the top on each side. This is a finely
detailed rope knot pattern with a small recessed frame around it.
Below the shoulder is the middle shoulder that touches the other
fingers. If you place the ring on a table it is lying on it’s side.
The sides have sharp edges separating it from the shoulder surfaces
that touch the other fingers. Can everyone visualize? By sharp I don’t
mean sharp enoug to cut your hand, just sharp enough to be cleanly
separate one part of the ring from another. A very clean distinct
corner or edge.

The ring has been emery finished to a 3M 320 grit. Either at the
bench in a small shop or with the GMX/sanding wheels in the polishing
room of the large shop (polishing part 2). The two starting items used
are brushes and felt wheels. The knot detail has not bee touched from
the cast. This may be one area that could be justification for
tumbling or stripping.

Here is the list of specific supplies I have selected. I use these
compounds and this process with both gold and silver. There is no
difference for me. I will describe the use and talk through the
sequence right after their descriptions.

3/4" medium unmounted bristle brush, buy a bunch (tripoli group)
Plastic spindle for these brushes (goes on tapered spindle of
polishing motor) 2 1/2" wood hub double row brush with 5/8" bristle
(tripoli group) 3" or 4" felt inside ring buff (tripoli group) 4" X
1/2" hard felt lap (tripoli group) 1 1/2" hard knife-edge felt
(tripoli group) 4" or 5" stitched yellow muslin buff with leather or
shellac center (tripoli group) Grey Star tripoli polishing compound
(water soluable stuff is working well) 3/4" soft unmounted bristle
brush (rouge group) 3" or 4" felt inside ring buff same as tripoli one
(rouge group) 4" or 5" stitched flannel buff with leather or shellac
center (rouge group) Small truing or Dressing stone (medium grit for
shaping felt wheels 6" or 7" wood drill stick (like a small wood
mandrel for holding rings) Leather 3/4" X 3" (made to fit around ring)
1 1/2" square of leather rubber finger tips (various sizes are
available from an office supply)

To start I do the inside of the ring first. This is done with rubber
finger tips on my hands and a cut strip of leather around the ring.
This gives me a good grip and protects my hands from the heat and mess
of polishing. The inside felt is screwed on the tapered spindle of the
polishing machine. If doing this for the first time and you have a
steamer, steam the hole of the inside felt. This will allow it to
screw on and stay in place. If it comes off while you polish do it
again. If you don’t have a steamer, make the wood of the inside felt
wet with hot water. The wood has to soften up to thread itself onto
the spindle. Charge the felt with tripoli and move the ring back and
forth with a firm pressure. Add compound polish it off. do that a
bunch of times. Do this until you remove all the emery scratches. If
compound is left on the ring inside you are not bearing down hard
enough. When done this looks loke a rouged surface. Look for no
scratches. If you see large scratch marks make sure they are not file
marks. You may not have emery sanded the inside enough. A bad casting
can show up right here.

The next step trades off between brushing and felt lapping with
tripoli compound. I usually start with the brushes. Work from the
small areas to the larger areas. Start with the 3/4" brush. Do the
smallest area being careful not to brush off the details. On the
signet ring I described, brush the knot on the shoulder carefully.
Move the brush around any way to reach the areas you need. Try to keep
away from the flat surface next to the design. Sometimes I go between
Grey Star and Bobbing Compound here (same brush). You charge the wheel
as needed. This is a hard thing to teach because every one has
different hand strength. You have to watch the metal get polished. The
compound flies off as it is used taking material with it. You keep
charging the brush every third or fourth surface contact. Again if
there is compound left on the surface you are not polishing hard
enough. When you are satisfied move on to the smallest knife edge felt
lap.

The felt lap will polish a bright and even recessed trench around the
knot. It is screwed onto the tapered spindle of the polishing motor.
Some may screw it onto the plastic spindle also. This felt needs to
be trued or dressed with the dressing stone to keep it’s sharp edge.
Add tripoli compound and polish. Be careful of the corners. Don’t
polish too much or you run out of the triangled frame/border of the
triangle knot. On any polishing project these first two steps may be
done in different order. The main point is that the details are done
first. You may switch back and forth here several times. It depends on
the project.

The large felt lap and larger brush come next. Still the tripoli
group. As the ring tapers from the flat top down through the
shoulders, this is a curved surface. Use the larger brush on this
surface. Brush away from the detail. Try to avoid polishing the detail
area again. You will remove detail if you are not careful. As a
general rule brush curved surfaces and lap flat surfaces.

You may also take the larger hard felt lap and polish right next to
the knot. The flat surface of the lap will allow this positioning. The
lap has the ability to polish the area and stay off the knot detail.
With the dressing stone a sharp edge on the lap can be made. Again be
careful not to hit the detail of the design. Moving to the hard felt
lap you use the bottom of the spinning lap and the side of the lap.
Polish the palm side of the ring with the bottom of the lap. The ring
can be on the wood ring stick for this. Move carefully up the shoulder
of the ring. The top of the ring will be polished with the side of the
lap. The ring sides are polished last again with the side of the lap.
All with tripoli. By lapping the sides and top last you maintain the
sharp corners and don’t round them up.

You can take the smaller piece of leather (an old belt works great)
and in the center cut a small “U” shape. Pop this little piece up. You
now have a leather holder for holding the ring while polishing the
side. Press the ring into this popped up piece of leather. This
leather will make side lapping easier because you now can get a better
grip on it.

The final part of the tripoli polishing is to take the yellow
stitched treated buff and lightly go over the whole surface. This
blends in all the brushed and lapped surfaces. GO LIGHTLY! This should
only blend areas together. If you have scratches anywhere go back to
brush or lap the surfaces. I also do the inside once more just to
remove any additional compound that has been left there.

The tripoli polishing is approximately 85% to 90% of all polishing on
any manufactured piece. The brushing and lapping are done to remove
scratches and leave the proper surfaces to maintain the finest
detail. If you are just using buffs to do all the tripoli polishing
you are taking longer to polish and rounding more of the surfaces than
fine jewelry requires. The variuos size brushes and laps are for
various size projects. I would follow this same sequence for polishing
most anything.

After cleaning the rouge is a snap. You use the other inside felt,
small soft brush and stitched flannel buff to lightly go over the
entire surface of you piece. These are not mixed with any other group
of compounds. If rough compound is left on the object any where you
need to apply more pressure. I usually don’t use do lapping with the
rouge. Rouge polishing is just making what you have into a mirror
surface. If there is a scratch left on the piece rouge will malke it a
shiney scratch. If there is a scratch you haven’t tripoli polished
enough. Rouge polishing is about 10% to 15% of all polishing.

For folks who do a lot of one of a kind and commission pieces, the
main difference is that you have various pieces pre polished before
assembly. I would use the same polishing process for these type
projects also.

I didn’t talk much about hallmarks and trademarks. This is done
several different ways and at different times. Some pieces are stamped
in the model before casting. Some are stamped before emery work. Some
are stamped after tripoli polishing. It all depends on how much of a
mark your stamping process leaves on the contact side of your piece.
You don’t want to go back and polish a second time. For example If you
stamp after rouge polishing you may have to go back and tripoli polish
out the mark left where the piece was supported while stamping the
mark. You decide when and where. On rings however the stamp is
traditionally done on the inside shoulder. If you look at the ring as
the face of a clock, the stamp is usually at the 3:00 or 9:00
position. This is because sizing is done at the bottom and the ring
may have a design at the top which prevents an under side support when
the mark is applied.

Now here can come either the best the worst part. The piece can be
either beautiful and customer ready or, porosity / firescale may be
noticed. Bummer. Sometimes tripoli polishing may polish off
firescale. Porosity is another thing. How do you get bubbles out af an
ice cube? Same thing with bubbles (porosity) in gold. That’s another
story. I won’t comment on that at this point.

The next and last polishing tool time will cover equipment next week.
Sorry if there are spelling errors this program has no spell check.

All the Best,

TR the Teacher,
Tod Hawkinson


#2

Todd: Great post. And some great tips, too. Here’s one for you: Line
the bottom of your polishing hood with some sheet styrofoam. If, by
some accident, a ring should escape your grasp and get pulled into
the hood by the force of the buff, it will harmlessly bounce off (or
stick into) the foam, instead of ricocheting around the room.

Doug Zaruba