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Dying after tumble polishing?


#1

Greetings, I’ve just begun my first foray into tumbling as a
polishing/burnishing step. I’ve read with interest the debate on
vibratory vs. rotary tumblers – for now, I have a small rotary
tumbler and I’m using mixed steel shot with Vital TM-121 polishing
powder compound and water. This is for sterling, by the way.

My question is this –

  1. How do you know how long to let it tumble? Do you stop it
    periodically and check it? Any general guidelines?

  2. I’ve read about using clean sawdust to dry your pieces when
    they’re done. I don’t have any sawmills around to get an easy
    supply of the stuff. My husband pointed out to me that if the goal
    is complete drying, uncooked rice might work just as well, as it’s
    even more of a dessicant than sawdust. Has anyone tried this? How
    about the wood chips you get (i believe they’re aspen?) for lining
    hamster cages?

  3. Do you dry your shot in the sawdust as well? If so, how do you
    get it all out of the sawdust and clean again without getting
    sawdust into your next round of polishing?

Thanks!
Karen Goeller


#2

Karen: I’ve been using a small tumbler for quite awhile now, and am
very pleased with it. I use the mixed stainless steel shot, with a
burnishing compound from Rio Grande. I generally tumble for about 4
hours and then check to see if they are ready. Then, wash them in
soapy water and dry them with a cloth and let them air dry. The
stainless steel shot has held up remarkably well. I rinse it
thoroughly and let it sit in a strainer to air dry. I’ve had no
problem with it. If you are using the non-stainless steel shot, I
believe there is a risk of rusting- I would think that a good
rinsing and then using a hair dryer to dry then would work fairly
well. Good Luck and have fun with it. Sandra


#3
    2.  I've read about using clean sawdust to dry your pieces
when they're done.  I don't have any sawmills around to get an easy
supply of the stuff. 

G’day. I know the older jewellery books say to use sawdust, but
although I have plenty (I produce it in my workshop by the heap!) I
wouldn’t bother with it. I use soft tissues (paper handkerchiefs)
for drying both jewellery and for drying the shot (steel ball
bearings). Simply pour the liquid from the tumbler or vibrator into
a mesh kitchen sieve or strainer, hold it under the hot tap, shake
off excess water, then pour the shot into one of those foam plastic
trays you get from the supermarket. Rub the shot carefully with some
tissues, and that will dry them sufficiently. I have been using the
same steel shot for 2 years with no sign of rusting. Keep it in a
screw top jar. – Cheers for now,

John Burgess; @John_Burgess2 of Mapua Nelson NZ


#4

Sandra - You don’t specify what sort of strainer; from sad
experience I wanted to caution that it is better to use plastic than
aluminum. The aluminum can actually rub off on the steel shot, and
be carried to your work the next time you use it.

Jim Small
Small Wonders


#5

I’ve been using the same standard steel shot in a rotary tumbler,
variety of sizes and shapes, for over twenty years. I use a weak
solution of Borax (from the supermarket, very cheap) and water. I
have never removed my shot from the tumbler between the times I use
it. I leave it in the tumbler in the Borax solution. This keep
oxygen out and prevents the shot from rusting. I’m lazy! I don’t
like the idea of drying the shot and have never done so and have
NEVER HAD MY SHOT RUST. Yay, hooray, less work for me! Every so
often I wash the shot and make fresh solution (when it looks dark
or murky). Once a year I wash the shot and run the tumbler for a few
hours with water and a little Ivory soap flakes or powder, just to
brighten up the shot again. Then I rinse the shot and the tumbler
and store the shot in the tumbler again in fresh Borax solution.
Voila. . .no need to spend the money on stainless steel shot. . .no
need to dry the shot each time you have used it.

Linda


#6

I’ve never heard of anyone dying after tumble polishing but maybe
that’s because tumblers are usually too little to climb into. C’mon,
I’m just having fun – I know you meant “Drying.” Maybe there’s some
method that uses sawdust or another desiccant for shot-drying but I
don’t think it’s needed. (Some people use sawdust, ground seed hulls,
etc. with various grades of polishing agent to tumble-polish castings
without using shot. I tried it once and didn’t like it – I spent a
whole day picking bits of walnut hull out of crevices in the polished
castings). I’ve never heard of the additive you’re using so follow
the manufacturer’s instructions carefully.

You’ve left out important Are you using carbon steel
shot or stainless? It makes a big difference. Carbon steel will
easily rust and you have to take a quick and active role in drying
it. When I used it long ago I lined a kitchen collander with
cheesecloth to hold the shot while it drained. I rinsed it with the
hottest water I could get out of the tap to pre-heat the shot to
hasten drying. I had big terry towels laid out to vigorously dry it
after rinsing and draining, then spread it out under heat lamps on
fresh terry towels afterwards. I think I also used a hair dryer set
on the “hot” setting. I got rust. I tried heating in an iron skillet
to dry it. I still got rust.

Maintaining the shot was as much hassle as polishing the Sterling
manually. I tried some suggestions about leaving it immersed in
various liquids between uses but ended up with useless rusted and
pitted shot. I tossed it, took a deep breath and invested in
stainless. I’ve never regretted it. I’m still pretty careful,
considering the cost, and have had no problems. I rinse as described
above, then dry in a towel and hit it with a hair dryer until I can
find no sign of moisture, then store it in a covered plastic
container until the next use.

There have been lots of threads on this and you’ll find useful
in the archives. One thing I’d like to emphasize is that
without a flow-through system, you need to change solution in the
tumbler frequently or you’ll end up with both shot and silver covered
with a nasty black substance that’s very difficult to remove. I have
no idea how long this would be in a rotary tumbler but I’d err on the
side of caution.

As for knowing when polishing is finished, simply open the tumbler
and rinse off a few pieces periodically to check. I use a vibratory
tumbler with plain old soap powder and I usually get a very
satisfactory polish within 30 minutes to two hours. A lot depends on
how well your castings were prepared prior to shot-tumbling. I
manually de-bur castings after removing the sprues, using a
combination of Mizzy and silicone wheels on the flex shaft. My first
tumbling operation – a couple of hours on average – is with
fine-grade quartz-impregnated plastic pyramids. Check this process
often to be sure detail in your castings isn’t being worn away.
Clean the castings thoroughly and tumble with shot. That’s what
works for me.

Rick Martin


#7
You don't specify what sort of strainer; from sad experience I
wanted to caution that it is better to use plastic than aluminum. 

Another reason to avoid an aluminum strainer with your tumbler: If
you’re straining polished stones from the tumbler, the aluminum will
leave “scuff” marks on the polished surface of the stones.

Personal experience…

Dave

Dave Sebaste
Sebaste Studio and
Carolina Artisans’ Gallery
Charlotte, NC (USA)
dave@sebaste.com


#8
One thing I'd like to emphasize is that without a flow-through
system, you need to change solution in the tumbler frequently or
you'll end up with both shot and silver covered with a nasty black
substance that's very difficult to remove. 

I don’t know that I’ve ever had occasion to disagree with you, Rick,
but I guess there’s a first for everything! Sorry, buddy! I did like
your joke, though! :slight_smile:

My vibrating tumbler doesn’t have a flow-through system and I’ve
never had the problem you described. Not only that, but as you’ll
read in the next paragraph, compared to the way you take care of your
shot, I’m downright negligent. Big terry cloth towels? Right… my
dog is lucky to get them after a bath! :slight_smile:

I do agree about the stainless steel shot. Like Linda, I’m too busy
(lazy?) to spend my time taking care of shot. I never had the carbon
steel, I invested in the stainless right off. Honestly, I don’t know
that I’ve ever removed the shot from the tumbler since I first set it
up. It remains covered in the burnishing liquid, in the tumbler…
the original batch of liquid I mixed when I first set it up. Granted,
a change of liquid is long overdue. I just cleaned out my ultrasonic
this week… the tumbler is next. I haven’t noticed any degradation
in performance, it’s just hard to see through the murky liquid when
fishing for my pieces.

As a lazy man’s solution, this was ideally suited for me!

Happy Easter to my Christian friends and Happy Passover to my Jewish
friends!

All the best,

Dave

Dave Sebaste
Sebaste Studio and
Carolina Artisans’ Gallery
Charlotte, NC (USA)
dave@sebaste.com


#9

Friends-- Does everybody really remove and dry their shot after
tumbling?

My experience with a tumbler comes from the art center where I
teach. We used the same steel shot (not stainless) for 8 years that
I know of, and it was never dried. As long as the liquid level
covered it, it didn’t rust. When it did get a bit rusty, we’d rinse
it, put in new liquid, and that’s all. Now we have stainless, and it
has never been out of the solution, either. No problems. Why remove
and dry it? Noel


#10
I don't know that I've ever had occasion to disagree with you,
Rick, but I guess there's a first for everything!

Dave, disagreement is fine! That’s a big part of the learning
process for all. I think one reason you may be a little more
laid-back about taking care of your shot is that you didn’t start
with carbon steel! That stuff can fill you with fear and a general
sense of impending doom.

In actual practice I’m a lot less scrupulous than I suggested but I
didn’t want to steer anyone in the wrong direction. I do very little
work in Sterling these days – I tumble mostly gold in a magnetic
tumbler. When I do use stainless shot in the minisonic I remove it
between uses though.

As for black gunk, there are so many variables in equipment,
additives, metals, etc., individual mileage can vary a lot. I think
I had the problem when using carbon steel and let the machine run
overnight. What a mess! I can’t recall any similar difficulties
with stainless but I still change solution if it starts to turn dark.
It only takes a couple of minutes.

Rick Martin


#11

I never dry my stainless shot. I was told when I bought it that if I
kept it covered with water or solution all the time, it wouldn’t
rust. And it’s been true; the only time I’ve had any rust was when
somw of it accidentally got dried.

Janet Kofoed