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Using tumblers to workharden plated items


#1

Can anyone advise me on using tumblers to workharden plated items?
Specifically with pure gold on pure silver? The gold would, I think,
rub off but I’m sure that if anyone can manage it, they will be on
Orchid!

best wishes
Stevie Gamble


#2

Stevie - You can work harden almost anything in a rotary tumbler
with stainless steel shot. The steel should be the stuff sold for
jewelry applications so it doesn’t have sharp edges. Add your work
pieces to a rotary tumbler filled about half full with the shot, and
a good burnishing liquid to make everything move freely. Run for an
hour or two. Voila, hardened pieces. Since there is nothing
abrasive in the process, your plated items should be just fine.

Q. If you are having these plated, why not harden them first?

Judy Hoch, G.G.
@Judy_Hoch
www.marstal.com


#3

Hi Stevie,

 You can work harden almost anything in a rotary tumbler with
stainless steel shot.

The same holds true for a vibratory tumbler. Vibratories are faster
than rotaries. Use the same assorted shapes of stainless steel shot.

Dave


#4
     You can work harden almost anything in a rotary tumbler with
stainless steel shot. 
   The same holds true for a vibratory tumbler. Vibratories are
faster than rotaries. Use the same assorted shapes of stainless
steel shot. 
	Rotaries are much less expensive, easier to fix.I have been using

the same rotary for polishing for 8 or 9 years, same barrels. I
tumble for 1 to 2 hours with stainless steel shot and get a bright
shiny finish. I do wholesale manufacturing, 500-1000 pieces a week
for a earring, pendant and bracelet line. I use vibratory for media,
rotary for tumble polishing. I was fortunate to find an old
photograpic print dryer with rubber coated rods that are 1 inch dia.
by 22 inches in length that I put pillow blocks on each end and a
pulley with a 1/4 hp motors that just keeps turnin’ it
around and around. I can run 4 lortone 8" barrels at one time.


#5

A vibratory tumbler and a rotary tumbler loaded with steel shot will
produce the same results in the same amount of time. There is no
time advantage to the use of a vibratory tumbler for steel.

Further the vibratory tumbler will be much more expensive to move
the same amount of steel. The steel needs to move in a random
motion to burnish items. Just because the steel jiggles in a too
small tumbler doesn’t produce burnishing.

Vibratory tumblers excell in moving abrasive and light weight media.
Rotary tumblers are work horses that are best used for moving heavy
stuff - like steel or rocks.

Judy Hoch, G.G.
@Judy_Hoch
www.marstal.com


#6

At this years Santa Fe Symposium Steven Alveti presented a paper
titled “The Effects of Burnishing on the Surface of Cast Gold and
Silver” He measured the hardening effect of burnishing as one of the
tests he ran. He tested disc, vibratory, roll and pin (magnetic)
burnishers. Unfortunately he did not test barrel (rotary) type
tumblers the roll burnisher he tested is a new type of machine. He
did comment about the barrel tumbler saying it was not as good as
the other machines for burnishing due to increased impingement of
parts on each other, not finishing recessed areas as well, slower
time cycle, and the inability to have flow through of the burnishing
solution. I would have liked to see the barrel tumbler tested as
well to show the differences but he did not do it . I assume this
was due to the fact that his business focuses on high production
rate equipment.

Anyway one interesting thing was that the vibratory, roll and pin
burnishers all provided the same level of average surface hardness
increase, 22% for silver and 8% for gold the disc was lower at 13%
for silver and 2% for gold. There were differences in appearance and
how well the hills and valleys of the surface were smoothed out
between each type of machine.

If you get a chance his paper is a good one it is published in the
Proceedings of the Sixteenth Santa Fe Symposium (2002) which is
available from Rio Grande. Also Steven Alveti’s company has a
website with a good paper titled "THE PRACTICAL GUIDE TO MASS
FINISHING OF PRECIOUS AND COSTUME JEWELRY: METHODS AND MYTHS"
http://www.belairfinishing.com/practical_guide_to_mass_finishing.htm

I found it interesting to read.

Jim
James Binnion Metal Arts
Phone (360) 756-6550
Toll Free (877) 408 7287
Fax (360) 756-2160


@James_Binnion
Member of the Better Business Bureau