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Tumble Polishing/Burnishing

I just bought a small, 1.5 lb Lortone Tumbler and a couple of pounds of
steel shot which I plan to use to burnish my sterling silver. Someone
suggested that I use Murphies Oil Soap as a burnishing compound, and that
I store my shot in the soap to keep it from rusting. I have a few
questions: - Has anyone tried Murphie’s soap as a burnishing compound. Did
it work and did it keep the shot from rusting while in storage? - What
other suggestions do people have for burnishing compound and and anti rust
storage? - How much of my two pounds of steel shot should I put in the
1.5# drum ? How much soap? - How long does it typically take to burnish a
piece of sterling ie ring or pendant. I have been told about 5 days. -
Any other tips?


Dear Milt

I tumble finish some pieces in steelshot and find that if the pieces are
cleanly cast with some prefinishing, it never takes more than an hour or
two to finish them. If you have larger flat surfaces you may have to
repolish them with a flat felt buff, since the steel shot tends to dimple
them. Hard plastic tumbeling drums are more suitable than the neoprene
drum I think you have. Over time the neoprene can coat your shot and
jewelry slightly leading to a less attractive finish. Rio Grande has shot
restoring compounds that can help re-shine your shot if this happens. I
used neoprene drums for a long time with pretty good success. I always use
a borax soap, could be that Murphys works just fine, I don’t know.

Good tumbling -Tom T.
Artisan Workshop

I’ve had my good ole Model 3A Lortone tumbler for at least ten years.
I’ve been using Rio Grande"s burnishing compound (powder) You need to use
very little…about 1/2 teaspoon at a time. Fill the tumbler about
1/3-3/8 full of shot and add enough water to go about 1/2 inch above
the shot. add the burnishing compound, throw in your sterling, press the
inner lid tightly against the flange,cover with the outer lid, stick on
the washer, screw on the knurled knob (but not so tight that you can’t get
it off…) set it up, turn it on, and voila! In less than half an hour you
should have a gleaming piece of jewelry. 5 days? You’d probably wear all
the detail smooth .You can always take it out and look at it to see if you
have the desired finish. I usually store my shot right in the tumbler. If
the solution gets dirty I empty the tumbler, wash the shot and start all
over…but it never gets rusty. Other people have other recipes for
Lortone or other tumblers, but this has always worked for me.

Hi Milt,

Most any low or no sudsing soap will work as a burnishing compound. I use
diswasher detergent (1/2 tspn) & add about 2 oz (a shot glass) of
household ammonia to the mix as the only liquid. This all goes into a
vibratory tumbler with about 7# of mixed shapes of shot. You may want to
adjust the quantities for your size tumbler. If Murphy’s Oil Soap is a
low/no sudsing soap it should work, but why buy it if you’ve got dishwash
er detergent?

The ammonia-detergent mix does a good job of keeping the carbon steel shot
from rusting if the cover is kept on the tumbler tightly when not in

When the shot begins to feel gummy or looks grungy or like it may be
starting to rust it’s time to clean it. Actually, depending on how often
you use it, it’s really better to set up a cleraning schedule. Clean shot
does a better burnishing job than dirty shot. Any dirt mixed with the shot can
cause metal being burnished to be pitted, or roughened. The amount
of pitting/roughening depends on the size, quantity & hardness of the dirt.

To clean it cover the shot with water & pour in some Draino or lye. Let i
t run a while & rinse off the shot in hot/watrm water. Dry in a bath
towel & return to the tumbler. If it’ll be used right away add the
soap & ammonia, otherwise let it dry & replace the cover thightly.

A good stainless steel shot will solve the rusting problem, but it’ll still
need to be cleaned from time to time. In the US stainless shot sells
for about $13.00 a pound. Thunderbird Supply in Gallup New Mexico has the
bes t prices I’ve been able to find.

The polishing media in a rotary tumbler should fill the container just a
little over 1/2. When in operation the media assumes the shape of a small
hill with the bottom of the hill being carried to the top by the rotating
tumbler. When it reaches the top, because of gravity, some of it slides t
o the bottom faster than the barrel rotates. The polishing/burnishing
takes place in this sliding layer.

I’ve never used a barrel tumber to burnish silver, so I can’t estimate the time
required. A small vibratory tumbler does the job in about 1/2 hour
o r less. The new magnetic tumblers also take about 1/2 or less. The 5
day (120hrs) figure seems about right for polishing rock depending on the
grit & material.


I assume you have stainless steel shot. If not, I don’t know how to
help you. But I agree with the other readers, Borax or the special
"soap" from either Rio or Gesswein (I use Gesswein) is great. I have had
my tumbler for about 10 years now and bought one for my school’s studio.
Great alternative to buffers with no ventilation. Safer too.

Clean everything out really well. You should only have to tumble for a few
hours and not overnight. when you stated that you ran it for several days
adding new jewlery, did you clean it out between each session? I’m
wondering if the rubber reacted with the soap somehow.

Trying hard to send rain from the East Coast to my friends in Florida. –
Karen Christians M E T A L W E R X 416 Main St. Woburn, MA 01801


Current Artwork:

I am not an expert on this. But I have heard this from more than one
source. Any 2 metals and water make a Di-electric (battery). You are
actually making a small electrical current in the tumbler. Short tumble
times makes no difference, but longer tumble times you actually
electroplate the steel shot onto the silver/gold in the tumbler. Only
way I have found to get rid of this is to either burn the dark coating
off again, or re-tumble this in the ceramic media, and then re-burnish.

Sorry but I have found a solution to that. You are saying that no chemical
helps. But I have found a dealer here who sent me some chemical powder
that when I put into these blackened steel balls cleaned them out
completely in one go. It was truly amazing because these steel balls were
very difficult to clean even with just tumbling and this chemical did it
just like that.


PS. I am at present visiting USA so I get to axcess my e-mail
intermitently since I am travelling to 11 cities.


Manjo…why dont you tell what that chemical is so we all can benefit
from it thanks

Manoj —Please! Who is the dealer and what is the name of the
chemical?You’ll make a whole lot of people very happy if they could
find a foolproof method of cleaning their steel shot. Enjoy your stay
in the USA.