Magnetic tumblers

In regards to magnetic tumblers, I think some of you may be
confused as to their function. I purchased mine, a Yasui, two
years ago for $4500. They have come down considerably since then.
I�ve been a manufacturing jeweler for 32 years and have breathed
my share of cyanide. The magnetic tumbler completely eliminates
cyanide bombing on castings and does an incredable job of
polishing hard to reach areas in twenty minutes . I even use it
on repair jobs for cleanup after soldering. It is the most used
piece of equipment in our shop. I don�t know how I got along for
30 years without one. Does anyone out there want to trade wax
models. Bye for now, Richard Olson (Bench Monkey)
OlsonDesign

Richard, I can see that you use your magnetic tumbler, and it
does the job well for you. But how does the tumbler actually
work. What is the magnetism for, and what purpose does it serve.
Richard W UK

Just a word of cation - I found out the hard way that you can
not put any metal into machine that has been pickled. The result
is a plating of steel onto the object you want to shine and it
seems to ruin the metal shot. Has anyone else had this trouble?
With the expense of the stainless shot and no metion in the
instructions it is a very costly lesson. Ron

Just a word of cation - I found out the hard way that you can
not put any metal into machine that has been pickled. The result
is a plating of steel onto the object you want to shine and it
seems to ruin the metal shot. Has anyone else had this trouble?
With the expense of the stainless shot and no metion in the
instructions it is a very costly lesson

Interesting. I have had the same problem, but I didn’t know
what it was: my silver castings seemed very grey and dull after
barrelling. I too would welcome suggetions for curing this
problem.

Dauvit Alexander

Perhaps you mean the parts and shot turned black? That is
common to magnetic tumblers and neither your parts or shot or
ruined. Stainless steel shot is, I’ve found, “tempermental”. It
stays bright for a while then turns black. I’m sure there is a
scientific explanation - I just don’t know what it is.

Meanwhile there are a couple things you can do to rescue the
shot.

First try changing the soap you’re using. If you’re using an
acid based compound, switch to an alkaline base (check with your
supplier) -or- if you’re using alkaline, switch to acid base.
That will clean the shot right up. Keep using the new soap until
the shot turns black again (and it will), then switch back to the
old soap.

Another thing that works is Coke. Yup! Coca-Cola - new or
classic it doesn’t matter. :slight_smile: Use a 50/50 mix coke and water
and tumble that black shot for 15 minutes, then empty the mix and
do it again for 15 minutes. Keep doing it until the shot is
clean. You CAN run your shot this way if you want, but it’s
kinda sticky. Try it - it works even tho it sound way out
there!

Best Regards,
Elaine Corwin
GESSWEIN USA

Ron.

I have put pickled items in without trouble, but they are
rinsed. It really brightens them up nicely. I have found that
what I assume is oxidation can build up on the steel needles and
give you dull results. I just rinse the bowl with the steel shot
until the water runs clear and add the soap and run it. You can
also run it with coke (pepsi will probably work) and that will
clean it I am told. If you put in an item directly from the
pickle without rinsing, I would think that the pickle would be
diluted in the water enough to have no effect. If you put a
couple of teaspoons of pickle in then you may have trouble. What
did you do exactly?

Mark P.

Hi Gang,

Just a word of cation - I found out the hard way that you can
not put any metal into machine that has been pickled. The result
is a plating of steel onto the object you want to shine and it
seems to ruin the metal shot.

I’m not a chemist, but from what I remember from my college
chemistry, you may have a liquid in your polisher that’s acting
as an electrolyte. This causes the different metals (silver,
stainless steel) to act as plates of a very simple battery. One
of the results is plating, just like what occu rs when you put a
piece of ferrous material in your pickle with the silver.

Be sure to rinse your silver off very well after removing from
the pickle If you don’t, you may transfer enough of the pickle
to cause the tumbler liquid to act as an electroyte.

As an experiment you might try washing you barrel out & shot off
with wat er & Draino (or lye, sodium hydroxide), rinse & refill
with just plain water Put in a few test pieces & see what
happens.

If all else fails contact the mfgr, he may have a solution.

Let us know the solution.

Dave

greetings all

A question or two regarding magnetic tumblers.

After annealing our metal, and as a prepolish preparatory step,
we’ve been tumbling our pieces in the magnetic tumbler for two main
reasons - First, to shine up some of the recessed areas that would
otherwise be difficult to reach.Second, to creat a work-hardened
skin on the surface of the pieces.This work-hardened skin reveals
underlying porosity, which makes it easier to attack them all before
we start polishing.The skin also acts as a somewhat work-hardened
surface, ever so slight, and the hope is that it is more
scratch resistant, and it takes a better shine.

So depending on what metal we are tumbling, say 18ky and 18kw, pt
900 and one of the platinum HCA’s, is it possible to achieve
surfaces of varying hardnesses, using different size steel rod,
tumbling speeds, and tumbling time??? And what exactly is the purpose
of adding the detergents to the bath?? Various suppliers recommend
different detergents for different metals.

Jason Sartor