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Tumbling problems


#1

I purchased a vibratory tumbler to cut my production time and am not
having the greatest results. I checked the archives and have not
found a solution. I have called the co. I bought it from for some
help and am still having problems. Their answer was, “Experiment!” I
bought it because many people were telling I was bonkers to spend all
that time at the wheel and I realized for my small silver charms I
was. They said, “Get a tumbler and you will save tons of polishing
time for the same results.” So far, not so. I am using mixed
stainless steel shot, burnishing compound and water. My pieces are
all filed and sanded and ready as if I am going to polish them on the
wheel…When I took my pieces out of the tumbler after a few hours
they looked like pieces of galvanized steel – shiny parts and dull
parts. So I cleaned the water and shot, added more compound and let
it run again…still kind of shoddy. Again the change and this time
I let it go overnight. Same thing!!! I have enough shot in the
bowl as the pieces are rotating and going under the shot. I know
there has got to be a solution to this problem and am willing to give
it a go, or the machine goes back to the store (this may not be an
option though and I will be out many $$$), and I will have more hand
polishing to do and will not be able to service my customers as
quickly as I would like to. I got the vibratory tumbler because I
was told I would get better and more quicker results than a rotating
tumbler. ~Elle


#2

Get get the little book by Judy Hoch “Tumble finishing for handmade
jewelry” from Rio Grande Item #550-774 $9.95 If you don’t have a Rio
catalog get that too. They carry all the materials. Don’t give up.

Jesse


#3

Elle -

I'm not an expert on using the vibrating tumbler for polishing

metal, but I think that you have omitted a step. Burnishing is the
final step; you need to use polishing media first unless you have
already brought the charms and such to a high semi-polish. I’m
certain other members will be able to recommend their favorite media
for the actual polishing. Good luck, and hopefully have fun!

Jim Small
Small Wonders


#4

Elle ,

where on the pieces are the dull spots? how much compound are you
using in solution? also how much liquid?? it’s hard to guess at your
problem and i’m sure if you can provide a little more info someone
can help. the process you’re using is like burnishing the material so
the longer runs should get better results. the vibs at my old job
used to run for long periods as i recall. as i mostly did model
making i am somewhat rusty on vibs but i know that my barrel polisher
tends to get better results with longer run times.
Talk to you later Dave


#5

Elle, I too have had this problem with pieces I tumble. I use to use
steel shot, too much trouble to clean, so now I use stainless steel
mixed, with burnishing compound and the silver pieces are all coming
out coated or glazed with a dingy grayish look, far from just a
burnished look, worse than before I tumbled it. I,m thinking it may
be my rubber barrel that I used with the steel shot previously in it,
even tho I cleaned it throughly. Maybe I need a new barrel. But you
have a new barrel so I am curious to hear responses to this problem.

Nancy


#6

I love my tumbler!!! I recently put a question to the orchid group
about bending small tubing. I was touched by the number of
responses. Thank you everyone!!! I am glad that I can now
contribute something. I first tumble using a medium pink tumbling
media and water mixed with burnishing compound both from Rio Grande.
I usually tumble over night. I then use stainless steel shot again
mixed with burnishing compound mixed with water and tumble over night
and once in awhile I will go a second night. I have had great
results. I hope this helps you.

Barb


#7

Elle,

There are various procedures to mass finishing that should be
followed to achieve optimum results. Steel shot is a burnisher and
will only brighten the look of your pieces to the degree that the
surface is deburred prior to this burnishing step. I have mass
finished (tumble finished) many different materials and found that if
you skip the deburring stages on most items, the result of the burnish
stage will not give you these optimum results. Deburring of the pieces
is done with various grades of abrasive cutting media and compounds
that facilitate the removal of the “outer skin” leaving a smoother
surface for your burnish/final polishing stages. You might check the
archives for some past recommendations on this subject. Rio Grande
also offers a mass finishing sample run free-of-charge, which will
give you their recommendations for a complete process, with all
factors worked in using your pieces. Also, Judy Hoch has a book
available through Rio Grande that might be very helpful for you.
Please feel free to contact me at @Joe_Lovato. I am
sure we can assist you with a proper solution to your finishing
issues.

Joe


#8
   I purchased a vibratory tumbler to cut my production time and am
not having the greatest results.  ...I was bonkers to spend all that
time at the wheel and I realized for my small silver charms I was. 
They said, "Get a tumbler and you will save tons of polishing time
for the same results."  So far, not so.  I am using mixed stainless
steel shot, burnishing compound and water.  My pieces are all filed
and sanded and ready as if I am going to polish them on the
wheel..When I took my pieces out of the tumbler after a few hours
they looked like pieces of galvanized steel -- shiny parts and dull
parts.  So I cleaned the water and shot, added more compound and
let it run again...still kind of shoddy.  Again the change and this
time I let it go overnight.  Same thing!!!!!  I got the vibratory
tumbler because I was told I would get better and more quicker
results than a rotating tumbler. ~Elle 

Possibly your charms have some indentations and small crevices that
the shot cannot get into??? I which case I would say you need a finer
medium, or something with some edges or points that can get into them.
And you still may not be using enough of the shot – it needs to do
more than just cover the charms; I have my tumbler barrel about half
full of the shot. Or you may have too many charms in there for the
amount of shot you are using. they need to be polished against the
shot, not against each other! I use a rotating tumbler (with the same
thing in in you are using) and it takes abut an hour to polish a
piece. (This is for the final polish – after I have first gone over
it on a wheel with tripoli.)

Margaret


#9

Hi Elle,

I believe I can help with your problems.

Yes, using a tumbler can speed the finishing process as long as it is
done right. As you have found out burnishing alone doesn’t work.

You won’t get the exact same results as hand polishing. But for
silver pieces very rarely can you sell them for what it costs to hand
polish. The first thing is to have the right tumbler and the right
media for each step. A Vibratory tumbler can work for all steps
depending on the piece.

Steel shot is a burnishing or final polishing for your pieces. It
can’t polish unless your piece is already smooth. No file marks and no
’sanding’ marks. Think of it this way. When you hand polish you don’t
just use say red rouge and skip all the other steps, right? It’s the
same with tumbling.

There is a difference between hand polishing and tumbling. A very
important one is the fact that buffing and hand polishing doesn’t take
metal off the surface. Basically it ‘moves’ it. The cut down steps of
tumbling will remove metal in order to create a surface that can be
polished/burnished using a burnishing media. This is important to know
because if your piece is left in the cut down steps too long you will
lose detail and possibly all detail. I’ve seen pieces in high
production shops that are difficult to tell they are the same as the
original. The original is usually very beautiful and without seeing it
you would think the tumbled piece is pretty as well but next to each
other the tumbled piece is very ugly. So with this in mind you may
want to exaggerate the detail on your pieces especially if the surface
is very rough and requires a good amount of time in the cut down.

There is some truth to the statement that you will need to experiment
but that is just after you understand what the process is and have put
some pieces through. All pieces are not created equal. Some will
require more time in the cut down and some less. Some will not fare
well in a vibratory tumbler and would do better in a barrel and only
big heavy pieces should be placed in a centrifugal disc machine.
Cent. disk machines create a tremendous amount of force and will
literally wad up a light ring or any filigree. As with all things in
the jewelry industry proper tumbling too is something that comes with
experience and is nearly impossible to write out on paper because the
variables in each style are different and since there are an infinite
number of designs you can quickly see that categorizing them would be
an impossible task. Sometimes it is hard to tell which type of tumbler
would be best. Another factor is how do you want the piece to look
when it is done. My idea of what it should look like may be different
than yours and everyone else’s.

Don’t say ‘I want it to look just like I hand polished it’ because it
won’t.

The prep work for the first stage in tumbling is to:

  1. If cast cut and grind sprue off.

  2. If fabricating do whatever grinding you feel it needs.

When grinding use successively finer grits until you are using
approx. 40 micron. If you use a finer grit it may reduce the time
spent in the cut down media. However, if your pieces are cast, using a
grit finer than 40 micron most likely will be a waste of time.

At this point your pieces will be ready for the first stage of
tumbling. This is a cut down stage. You should use a 'medium cut’
media. Usually a pyramid shape will work very well but a cone can work
too. The difference is what areas of your piece do you want polished
with the media. A pyramid because of it’s sharp corners and edges will
polish deeper in grooves and filigree. However if these are areas you
don’t want polished then a ‘cone’ shape would be better. These shapes
can be mixed if you don’t want as much polishing of the deeper areas
to happen as you would get with the pyramids alone. If you are
oxidizing your piece you will not need to polish the crevices very
much so a cone might be better. But then maybe overall you don’t need
the crevices polished much but a certain spot needs it, then a
pyramid is probably better. Again some experimenting.

Medium cut media is used to get the surface to the same general
finish. That is to remove/reduce any large surface scratches made from
grinding or other processes.

The solution you use should be matched for the metal type and the
media. It should not be a burnishing solution. When the tumbler is
running several things are happening. The media is abrasive so it is
wearing itself down and taking a small layer of metal off your pieces.
The job of the solution is to suspend the debris so it doesn’t clog
the media. If this happens your media is useless. A good solution is
worth the money. Also a flow through unit on a vibratory tumbler is a
very good investment. A larger amount of solution means better ability
to keep particles away from the media. Once the solution has been used
it isn’t a good idea to reuse it. It’s cheaper to use new solution
than to replace your media. Make sure the solution is mixed according
to directions as too much can impede the media also.

The tumbling action is important as well. The media should be
traveling in a double circular motion. The first direction should be
around the bowl either clockwise or counter clockwise. The second
should move the pieces down to the bottom and then back up. If these
two actions are not happening some adjustments need to be made. First
there may be too many pieces in the tumbler so it is too heavy. This
usually won’t happen if your tumbler is made for steel shot. The other
adjustment has to do with the counter weight on the motor.

The amount of time depends on the beginning surface and the desired
ending surface. This takes some experience and a small amount of
experimentation. Again the longer you run it the more surface will be
taken off. The media doesn’t care what the surface is and therefore
will try to make the entire piece smooth. This means any high spots
(like a nose on a face) will be worn down more than crevices until
the high spots are no longer there. The cut down not only smoothes the
surface for burnishing but will remove any fire scale and oxides that
will change the color of your final piece.

It’s easy to say that mass finishing can save time and money but it
is give and take. The take is a difference in the finished look of the
piece as opposed to hand polishing.

If your pieces are not very rough like they would be from casting
then you may be able to skip this first stage.

The second stage is to use a ‘fine cut’ media. This media is the same
as the medium cut except it is less aggressive. So choose it the same
way. The same kind of solution can be used here.

After this stage your parts are ready for the steel shot.

To use carbon steel or stainless. It’s a big question. I prefer
stainless for several reasons. Most importantly it doesn’t rust. So
you won’t have to eventually throw it out and there is no upkeep. Just
rinse and go. If you use Stainless and have people working for you
make sure they understand this. I had a couple of ‘rookies’ that
didn’t understand this and for some unknown reason they threw out
about 150 Lbs. of stainless steel shot. OUCH! That hurt. Stainless
doesn’t have to be stored in a special solution to keep it from
rusting like carbon shot and therefore the cost of maintenance
solution and labor to maintain it over a short period of time will
start costing more than the difference between the two. In addition
carbon shot once it has started to rust you will have a headache and
a very difficult constant battle with it which will eventually lead to
the disposal of it. I have seen so many people think they were going
to save a bunch of money with carbon shot and instead created a big
problem and ended up getting rid of it and buying stainless. This cost
them much more than just starting with stainless.

Again the solution for steel shot needs to be made for the metals
(gold, silver, carbon steel or stainless steel…) and for burnishing.
This time the solution is again mainly used to suspend particles but
also to help the ‘final’ polishing. So again a flow through unit is
helpful and the time is dependent on the desired outcome.

All these steps can be shortened or lengthened and if you don’t like
the final outcome you can revert a step or two and run them again. So,
now that you have run your pieces and they still may not be as smooth
as you want depending on how much of the surface needs more work you
can run them through either both cut down steps or just the fine
followed again by the burnishing step.

A final note to the steel shot issue. Ceramic media can also be used
and creates a very nice burnished finish. Be sure to break in the
ceramic media before attempting to use it for burnishing. It will also
require a different solution for it’s use.

This may seem like a large investment in equipment and supplies but
if your pieces are in demand the trade off is that you can mass finish
many more pieces more quickly in the same amount of time than by
polishing by hand. Mass finishing will also allow you to capture the
market faster and can increase sales by having more product available
for sale than you would by hand polishing. You can’t sell what you
don’t have and people usually change their mind if they can’t get it
now.

Generally a good place to start as far as times go is:

Medium cut run for 4 to 8 hours.

Fine cut run for 4 to 6 hours.

Burnishing with steel run for 2 to 4 hours.

These times will vary from design to design and if you practice
studying your pieces after they come out of each step you will develop
some experience for future designs and this will decrease your
experimentation.

Experimentation can be a disliked word but after understanding the
processes involved it can lead to more profit and new discoveries
which in turn can lead to more profits. More profit is what we are all
looking for, right?

If you have more questions or need more help let me know. i can be
reached at 877-262-2185 (toll free) or email at ken@mpgrepair.com. –
Ken Kotoski MPG Repair
www.mpgrepair.com


#10

I’ve just started tumbling pieces as well - and so far not satisfied
with the results it was suggested I would get.

One person (this may be the right one for you…) suggested that I
get the stainless steel shot (mixed) and use a rotary tumbler mixing
Rio’s deburring solution, descaling solution and water. I put some
pieces in (my work is the high polished look with stones). Pulled
them out after 2 hours and couldn’t believe my eyes. SO bright and
SHINY! But… being the perfectionist that I am, a much closer look
revealed tiny little random scratches. So… I thought, well… if
that took off the fire scale and all I have to do is a quick Tripoli
and then Buff. Fine - I can be immensely happy with that. So, off to
the tripoli I went - only to take off the shiny COATING of silver
plate this had put on the pieces. If you’re casting these charms (I
don’t know what your work looks like). This might be the perfect
solution once you have cleaned them up.

Then I invested in a Vibratory Flow Through system. $$$ Bought the
"clean cut" media from Rio. Pink, Blue, Green and Sunsheen Green
Buff. Took pieces through all of the manufacturers recommended phases
as well as what was recommended by other jewelers. Still doesn’t
remove fire scale in my opinion - some but certainly not all - even
after 24 hours in the tumbler. So, at present I am sitting with this
whole system and using just the pink with the two solutions to remove
some and to debur it ( soften the hard edges). Then I take it to a
shorter time of bobbing, etc., etc. I do feel it cuts down my time
some, but really, is Nitric Acid the only way to remove fire scale
without bobbing? Just can’t “go there” with using a chemical that
strong. yet…

Hope that’s helpful, Elle. If you don’t own one of those inexpensive
rotary tumblers but live near someone who does. I’d suggest seeing
if they would let you try it first. BTW - I found that the Sunsheen
green buff leaves a grayish film on the pieces, too.

jody


#11

ken

excellent article on finishing! very lucud . i was wondering about the
using of walnut dust? or something like in the finishing process with
vibs . production finishing is a murky area for myself so i might
have gotten the media name wrong. thanx for any advice people.

Dave


#12

Hey Elle,

Whoever sold you the tumbler did not give you enough info.

No matter how long you leave your pieces in shot they will not polish
away file or sandpaper marks. They work like rouge would, not tripoli.
Also, you need to add steel “pins” to your shot to reach areas the
balls will not.

You need to purchase ceramic media to put your work in before using
the shot. There are several shapes with varying coarseness’. These
will really save you time at the polishing motor but realise the time
in the tumbler is many hours compared to hand polishing. But, the
tumbler never asks for more pay or longer holidays and will work all
day and all night for little more than the cost of electricity.

There is so much more to know. If your supplier can’t help you let me
know and will gladly provide more info.

Best of luck,
Johnny.


#13

Hey Elle,

Whoever sold you the tumbler did not give you enough info.

No matter how long you leave your pieces in shot they will not polish
away file or sandpaper marks. They work like rouge would, not tripoli.
Also, you need to add steel “pins” to your shot to reach areas the
balls will not.

You need to purchase ceramic media to put your work in before using
the shot. There are several shapes with varying coarseness’. These
will really save you time at the polishing motor but realise the time
in the tumbler is many hours compared to hand polishing. But, the
tumbler never asks for more pay or longer holidays and will work all
day and all night for little more than the cost of electricity.

There is so much more to know. If your supplier can’t help you let me
know and will gladly provide more info.

Best of luck,
Johnny.


#14

Okay, one more thing… then out to the studio. Before we put the
tumbler question to bed, let me be the one to ask a dumb question. I
have a vibrating tumbler but don’t get much use out of it. Stainless
steel shot and burnishing solution. Gonna have to get me some of that
fine media… been following the thread with interest.

You wouldn’t put finished jewelry with set stones in there would you?
Obviously not something soft or fragile like turquoise or opal. What
about other stones like agate? I said this was a dumb question. :slight_smile:
But if you run your jewelry through before setting the stones,
wouldn’t the bezels get bent and distorted? What am I missing here?
Only used for certain types of pieces?

Okay, now I’m going…

Dave

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


#15

Tumbling tip: When I use the clean cut triangles and cones, I first
put some in a plastic sack then crush it in a big vice. For the
crushing process, I take small amounts of the stuff in the plastic
sack and put it in the jaws of the vice then tighten the vice, the
medium will crack and break. The clean cut medium then has more
sharp surfaces that is able to get into smaller places. I use a mix
of the crushed pieces with original shaped pieces. I have tumbled
rough castings of bronze and sterling in a rotary and vibratory
tumblers and this gives me good results. Linda Johnson Soda Springs,
Idaho


#16

Hi Dave, Marlo, Judy and everyone at Orchid,

First I want to apologize for not being able to respond right away to
your emails and posts. If you’ve ever had to deal with a banker for
your business you’ll know what I’ve been trough for the last several
days. They now know more about me than I do!

Anyway, I guess the best way to respond is to just start with each
email and post as they were sent.

So first Marlo sent this:

I too have had the rubber breakdown on the interior of my rotary
barrels with burnishing compounds making my silver
brown/grey/gunmetal
colored after a few hours of tumbling. I was probably using too strong
a solution of the compound, but since I never accurately measured, I
never figured out the right ratio for my gallon container.

I went in search of alternatives and was told that a squeeze "Dawn"
dishwashing liquid and water works better than anything else! And
wouldn’t you know it? They were right! I can tumble (rotary) all day
long and my work comes out shiny clean and yes- grease free! (an
unnecessary added benefit, but a benefit nonetheless!)

Hate to throw a wrench into the sales of burnishing compound, but not
to worry…I still use lots of deburring and descaling compound in my
vibratory tumbler!

One of the possible reasons you are having trouble more than likely
is the fact that your rubber insert has broken down. The reason it has
the rubber insert and why other tumblers are made of plastic is
because the metal will leave a steel looking finish on your gold,
silver or other material. So when your insert gets a hole or starts to
breakdown you will need to replace it. This is a disadvantage to
metal barrels. However I have built barrels out of acrylic that last
pretty much forever. The initial cost is slightly more than a metal
barrel but you don’t have the cost of new inserts all the time. The
acrylic barrels have other advantages as well, they are clear so you
can see what is going on inside and the only parts that need replacing
are the O-ring seal on the opening.

Dawn is used quite a bit throughout the industry but you need to make
sure it’s not the ‘Ultra’ version. Ultra Dawn is not the same thing as
Dawn. It is a different formula and you will quickly find out it
doesn’t work.

Next Dave sent this:

Okay, one more thing… then out to the studio. Before we put the
tumbler question to bed, let me be the one to ask a dumb question. I
have a vibrating tumbler but don’t get much use out of it. Stainless
steel shot and burnishing solution. Gonna have to get me some of that
fine media… been following the thread with interest.

You wouldn’t put finished jewelry with set stones in there would you?
Obviously not something soft or fragile like turquoise or opal. What
about other stones like agate? I said this was a dumb question. :slight_smile:
But if you run your jewelry through before setting the stones,
wouldn’t the bezels get bent and distorted? What am I missing here?
Only used for certain types of pieces?

First of all Dave there is no dumb question. If you don’t know
something it is only because you haven’t been exposed to it yet and if
you have been exposed to it you may have forgotten so again it is not
dumb to want to refresh your knowledge.

For tumbling with stone you definitely don’t want to place soft
stones in a tumbler. Unless you are just tumbling them like rock
tumbling. If you want to tumble finish pieces with stones you will
tumble the pieces without the stones in the cut down media first then
set the stones and tumble them in the burnishing media. Again only
’hard’ stones should be tumbled. For instance CZ’s, diamonds and so
on. They can be tumbled in either steel shot or ceramic media. Again
when using Ceramic media you will need to break it in before using it
to burnish. Ceramic media is different from the cut down media. You
can apply a coating to softer stones and then run them in the
burnishing phase but you will need to watch them closely. My
suggestion is to use some ‘junk’ stones and try it out first so you
can determine what will happen before placing your good stones in the
tumbler. Ceramic media will also be a wiser choice for these softer
stones since it is not as heavy and will have less tendency to damage
the stones. The steel will still work for the harder stones.

As for the bezels getting distorted; unless they are very thin and
soft you won’t have any problems. The forces in a barrel or vibratory
tumbler are not great enough to bend the metal. If you run your
tumbler and put your hand in the media while it is running you will
find that it is just rolling on itself. There is a little 'bouncing’
going on as well but is isn’t enough to bend metal. Any piece can be
tumbled it’s just a matter of how much time you might save (or not)
and the type of finish you want. If you have only one piece to make,
hand finishing is definitely faster than tumbling. But if you have
many pieces it may be faster to tumble finish. This is all subjective.
How close to a polish are your pieces before the polishing? Some may
be faster to hand polish if there aren’t too many of them, while if
there are thousands of them it would be faster to tumble. If the
amount of polishing is great and there are several pieces tumbling can
be faster.

Large mfg. usually tumble all pieces because they have set up a
system that includes tumbling and they make so many pieces that they
would never sell their pieces if they spent the money to have hand
finishing done on them. On the other hand is the fact that if you are
busy and you have other customers to attend to maybe tumbling will
help save you time. Once the tumbler set just put your pieces in,
turn it on and get on with your other work.

Judy posted this:

On the subject of removing material with buffing - you stated that
buffing doesn’t remove material. Oh contrare - buffing removes on
average 3 to 5 percent by weight - and sometimes much more. Tumbling
removes material but in the range under 1 percent.

You are right that rouge smears the finish, but bobbing and tripoli
both remove substantial amounts of metal. Use a scale and you can
measure the difference.

Yes, Judy you are right that bobbing and tripoli do remove some
metal. However I believe your percentages are reversed unless you
don’t run you pieces for very long in the cut down steps. Sometimes
this can be done but it is not usually the case when tumbling cast
pieces. What you are suggesting is that a 2 ounce item would leave up
to 1.8 grams of metal on your buffs. If you are only tumbling in the
fine cut media and then burnishing you may well only lose 1 percent
but most castings will need more tumbling than that.

From the tone of your post I have offended you and I didn’t intend
to offend anybody. I understand you have written a book about tumbling
and you have a right to sell it but I also have a right to freely
distribute the I have acquired. If this interferes with
your ability to sell your book that is what happens in a free
enterprise society. I am not saying this is what has irked you but it
was the first thing that came to mind since you specifically
addressed me and not the forum. I am here to help not to tear down
others and although I did make the mistake of saying hand polishing
doesn’t remove metal, in my mind I was thinking of the rouge step in
hand finishing. I wasn’t as clear about it as I should have been. It
is good that you pointed this out and I thank you for helping to
correct my mistake.

I hope this has helped everyone and if it has created more questions
I would be happy to answer them and with Judy’s help I’m sure not to
make any more mistakes.

Ken Kotoski
MPG Repair
www.mpgrepair.com