Since I’ll be buying a tumbler soon, I have a nitty little question,
sparked by Dave Arens’ comment over in the Making handmade chains
thread:
a little burnishing soap (2-3 drops of low sudsing dishwashing
detergent)
Do you mean regular old dishwashing detergent for washing dishes by
hand? The kind that is now almost exclusively concentrated? It must
be the “low-sudsing” that’s got me wondering; none of them actually
say low-sudsing do they? Do you have a favorite brand? Is the purpose
of this stuff to lubricate? And low sudsing laundry detergent will
also probably do just fine?
On a related issue, I was wandering thorugh a pet supplies store a
few days ago and notice that they sell all sorts of stuff for animal
bedding that might be excellent to use for tumbling in; specifically,
corn cob bits and walnut shell bits. I wonder how either might be
used and what could be added to them for various purposes, polishing
or whatever. If it’s something that can likely be found from the
local whatever supply place, that’s double plus good.
Thanks, Christine in Littleton, Massachusetts, who wants you to know
that no one deserves lung cancer.
Although you could probably use any “low-sudsing” dishwashing or
laundry detergent, I have yet to find one as effective as those
specifically made for the purpose of tumbling. There are several
reasons for using the right detergent. One is lubrication. More
importantly it acts as an emulsifier, keeping dirt and oil in
suspension and allowing it to be easily rinsed away. This insures
the parts you are tumbling stay clean and that dirt, oil and
impurities don’t interfere with the tumbling process. This is
particularly important when using cutting medias such as plastic
cones and pyramids which break down during the process. In a pinch,
I’ve used dishwashing detergent but I found I could not add enough to
do the job without creating a lot of suds. The low-sudsing
detergents made specifically for tumbling really do work best.
As far as picking stuff up in the pet shop for dry tumbling, I’d
suggest you screen it to remove the smallest particulate which will
otherwise get stuck in the tiny recesses of your jewelry. It’s a
real pain to pick out. Don’t try to wash it out. This stuff tends
to expand when wet making it even more difficult to remove.
Years ago I got hold of a dry media mixture from Germany. It was
composed of walnut shells (screened to about a 2mm size), plastic
balls (about the size of a pea), wood pegs, glass beads (about 4-5mm
diameter), felt cubes (about 1/4" square), and I can’t remember what
else. The stuff worked great – as long as you added some Simichrome
Polish. Unfortunately that company went out of business. But I got
into the habit of adding a variety of materials to my dry tumbling
media and results are mostly positive.
My recommendation would be to start with a base of standard dry
tumbling media such as walnut shells or corn cob made for tumbling.
Use Simichrome or other paste polish to charge it periodically. Use
only a tiny amount as you want the dry media to stay dry. Then by
all means experiment with additional materials (soft woods, plastics,
cob, etc.). Just be sure to screen it first. I think you’ll like
the results generally.
The best media I’ve found is from Otec, a German company. Many
suppliers, not just Gesswein, carry this brand. Their “regular”
walnut shell is a dry media that removes very light scratches (as
from wear). Their “extra-fine” walnut shell produces an extremely
high finish. Used in the Otec disc finishers, it’s the best finish
I’ve seen from an automated process.
The detergernt works mainly as a lubricant. The reason for the low
(or no) sudsing is that the suds don’t do any good, they just fill
the space in the tumbler & have to be dealt with when removing
things from the tumbler. I use whatever is handy. If I had to buy it
I’d get the cheapest kind.
Detergents & soaps can be used for lubricants for lots of metal
working applications. One of the things that makes them good for
lubricants, beside there lubricity, is they can be cleaned off with
plain water when the work is done.
FWIW: One time while touring a metal stamping plant, I watched the
press operator throw 2 hands full of Duz laundry soap on top of a 4
ft square piece of sheet metal before closing the press. It was a
5000 Ton press.
As far as using the walnut shells or corn cobs for polishing is
concerned. It’s already done, the stuff sold for polishing usually
has some polishing compound added to it.
One thing to be careful about if buying shells or cobs at a pet
store is cleanliness. If any grit or other dirt has found its way
into the material, it could affect the polishing.
An inexpensive tumbling soap I've used is generic "oil soap,"
like "Murphy's.
I don’t think a detergent would substitute, as I vaguely remember a
high school chemistry discussion (ca. 1969), that soap and
detergents both clean grease and oil based substances they do so by
opposite mechanisms. I seem to remember that some soaps and
detergents can even counteract each other(?).
Thanks to everyone who answered my tumbling questions.
Of necessity, I buy most of my supplies through the mail but I love
being able to buy things locally; I actually like to SEE before I
buy. For tumbling, it seems that materials made specifically for that
purpose are probably better; e.g., although obvious, it didn’t occur
to me that materials intended for pet bedding could also include
unwanted abrasives.
For right now I can probably do just as well by making do. I’ll use
the tumbler primarily to burnish, so lubrication is my main concern.
I may want to do something with beach stones in the near future and,
though I took care to pick out already smooth ones, I may want to
touch them up a bit. Due to the rugged nature of beach stones, animal
bedding would probably be fine. I’ll definitely screen it if I decide
to try it.
I don't think a detergent would substitute, as I vaguely
remember a high school chemistry discussion (ca. 1969), that soap
and detergents both clean grease and oil based substances they do
so by opposite mechanisms. I seem to remember that some soaps and
detergents can even counteract each other Hope this helps a few. Ed
Hello; Does anyone know if this is true or not and does it make a
difference in our work? What are their mechanisms for cleaning?
The detergernt works mainly as a lubricant. The reason for the low
(or no) sudsing is that the suds don't do any good, they just fill
the space in the tumbler & have to be dealt with when removing
things from the tumbler. I use whatever is handy. If I had to buy
it I'd get the cheapest kind."
Dear Christine and Dave, While it is certainly common jewelry
manufacturing practice to opt for the cheapest kind of anything when
the situation allows I would like to offer an alternative thought to
this discussion. You are absolutely correct on one of the main
functions of soap in mass finishing equipment to serve as a
lubricant, it is also a surfactant. It keeps the dirt or “abraded
surface metal” in suspension so that it can be rinsed away and not
imbedded back into the metal surface. There is another issue with
tumbling soap that you do need to keep in mind. The term chelation
is a word that is of incredible importance when discussing soaps used
for abrasive mass finishing operations.
(Certain organic compounds are capable of forming coordinate bonds
with metals through two or more atoms of the organic compound; such
organic compounds are called chelating agents.)
I am assuming that you run the effulent from your mass finishing
system through a settleing tank, filter, and an ion exchange before
you send it down the drain. If not, this is something else you
might want to consider. In any case you would want to choose a
non-chelating soap for use with your abrasive mass finishing system.
It is important for several reasons not to put your metal down the
drain. If you mainly make gold jewelry then the reasons are very
apparent, money. If your finishing silver, the money is not so great
but there can be ramifications that most people don’t consider.
Silver is an anti-bacterial agent. If enough of it reaches your
local water purification plant it can kill the live active agents
that are involved in water purification. I live in New Mexico so
those are issues of great importance around here.
If you use soaps that contain a chelating agent then it is much
harder if not impossible for the resin in the ion exchange columns to
remove the metal ions from your effluent water because they are
already attached to the chelating agents and pass right through.
There goes your money. If you use a non-chelating soap then the
metal ions can be trapped in the ion exchange resin where you can
recover them later in the refining process. So if your considering a
“cheap” soap, make sure it is not costing you more money in the long
run.
Best Regards,
J. Tyler Teague
JETT Research (consulting)
(Jewelry Engineering, Training, & Technology)
Dear J. Tyler Teague What are some non-chelating soaps? I’m getting
a place in NM soon, with a septic, so of course, I’d love to know so
I don’t kill all my precious little microbes .
Thought of something to go with your pet-bedding and stones. Why not
just buy an extra bowl for your tumbler and avoid any problem of
contamination. I wouldn’t use my bowls for tumbling precious metals
with anything else. I have spare bowls for rocks, or other things
like frosting glass if I liked, well marked, and can put any media
in without worry. Extra bowls aren’t so costly that they wouldn’t
be worth peace of mind concerning contamination. Love my tumblers.