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13 Tips for a Long Vibratory Tumbler Barrel Life

How they are used determines how long they will last.

Lot-O-Tumbler and UV10 tumbler barrels
Barrels for a Thumler's Ultra-Vibe 10 Industrial tumbler and a Lot-O-Tumbler. Ultra-Vibe barrels are made of heavy polyethylene. They wear slowly and can last for several years - if you learn how to treat them with respect and avoid some types of use. Lot-O-Tumbler barrels are made from high-density rubber and remind you of an automobile tire. With proper care they will last for decades.

Vibratory Tumbler Barrels Usually Last a Long Time

Vibratory tumbler barrels can last for a few months or last for several years. How long they last is enormously influenced by how you use and care for them. Here we have 13 tips for getting a longer life out of your vibratory tumbler barrels.

We have Thumler's UV-10 and Thumler's UV-18 Vibratory Tumblers running constantly in our warehouse. Their bowls are made from heavy polyethylene (most people refer to them as "plastic"). They will break if you drop them, and they are abraded by rocks and silicon carbide grit.

We follow all of the tips described below, and we get several years of life out of nearly all of our Thumler's bowls. We rarely replace one.

Bowls or Barrels?

Some people call them "bowls" and some call them "barrels". You can call them either and we will know what you are talking about.
We have a Lot-O-Tumbler Single and run it regularly. Their bowls are made of heavy "tire-like" rubber. They are darn near bullet-proof, and we have never heard of one wearing through. But, a few people still need replacement barrels. Most of those costly replacements could have been avoided.

We want to accomplish three things with this article:


  explain a few things about how tumbler barrels wear


  give you NINE common-sense tips to protect your Thumler's Vibratory barrels


  give you FOUR easy tips to avoid problems with your Lot-O-Tumbler barrel.

NINE Tips for Thumler's Ultra-Vibe Barrels

Wear Occurs During Every Tumbling Step

Barrels of the Thumler's UV tumblers lose a tiny amount of thickness with each batch of rocks.

This is normal.

After you run the tumbler with some rocks, dump them straight from the barrel into a basin of water, swish them around and wait a few moments... you will see tiny black particles float to the top of the water. They will be smaller than a grain of fine pepper.

These black particles are tiny pieces of the barrel. We see tiny barrel particles in the white mud of our polishing, and in the soap suds of our burnishing. Some loss of barrel thickness occurs even then. This is normal.

We want to help you keep this loss to a minimum!

Worn out UV-10 barrel
Here's how you can tell when your UV-10 barrel is getting close to "end of life". The bottom of the barrel starts getting so thin that you can almost see through it. Replace your barrel at this point to avoid cleaning up a mess!

What A Worn Barrel Looks Like

We have a UV-10 barrel that we used a few times a month for five years without it wearing through. During that time almost every rock that we tumbled spent its medium, fine, polishing, and burnishing steps in that barrel. It is the barrel in the accompanying photo with a translucent ring in the bottom.

We treated that barrel well. Most of the rough rocks that we processed in it were tumbled through the coarse grit step in a rotary tumbler (which removed sharp edges) or were tumbled stones from one of our suppliers that did not meet our polish standards for customer sales.

If we would have used this barrel for one or two more batches of rock, it would have started to leak rock mud through the bottom of the barrel.

The first sign that your barrel is failing is rock mud on the foam pad beneath the barrel. Watch for it! Better yet, each time you wash your barrel, hold it up to a window or a light and see if it is becoming translucent. That is the sign that you better get a new barrel - or you might be cleaning up a big mess.

9 Tips for a Long Vibratory Barrel Life

You control the life of your barrel. Learn and practice these tips.

We have been using vibratory tumblers for a long time, and we have learned a lot from customers, tumbler manufacturers, friends, and visitors to our website. Below we summarize everything that we know about extending the life of your vibratory tumbler barrel. We hope that these tips save you some frustration and money.

Tip #1:   Don't Use Coarse Grit!

We often hear about people using coarse grit (such as 60/90) in a vibratory tumbler. We absolutely disagree with using coarse grit in Thumler's UV tumblers. We disagree for three reasons:

1)   Coarse grit will aggressively abrade your barrel.

2)   Coarse grit particles are usually too large to stick to the rocks during vibratory tumbling. Many of them will slip off of the rocks and sink to the bottom of your bowl.

3)   Imagine this... You add several tablespoons of coarse grit, the particles are so big that they barely stick to the rocks, and they sink to the bottom of your bowl. Now they are at the bottom of your bowl - the exact spot where the bowl wears thin. And, circulating rocks - the biggest ones in your bowl - are plowing through that grit, dragging it across the bottom of your bowl, vibrating at 3000 VPM, with the weight of all of the rocks above pushing down.

These bowls cost over $100! Using coarse grit is just like burning money.

angular aventurine
Angular pieces of aventurine about 1" to 2" in size. Tumbling angular rocks like these in a vibratory tumbler can gouge the bowl, causing rapid, premature wear. It is best to tumble rocks like these in a rotary tumbler for a few days before placing them in the vibratory bowl. Click image to enlarge.

Tip #2:   Avoid Tumbling Angular Rocks in Vibratory

We were tempted to name this tip "How to Kill a Vibratory Barrel".

The greatest wear on an Ultra-Vibe barrel occurs when angular rocks - especially large ones - are tumbled. If a person is tumbling broken agate, broken jasper, broken petrified wood, or any other material in angular 3- or 4-inch pieces, the sharp edges of those big pieces will severely gouge your barrel! Those large sharp rocks will also rip into the foam pad that covers the bottom of the lid.

A few people have asked... "are the vibratory barrels guaranteed?" The answer to that is   "No!   They are not guaranteed!"   The length of your barrel's life depends upon how you treat it.

If you tumble big angular rocks, we guarantee that your barrel life will be very short.

We run all of our large angular rocks for at least a week (depending upon their size and hardness) in coarse grit in a rotary tumbler before placing those rocks in a vibratory tumbler. We do this because we prefer rounded tumbled stones. We also do it to reduce the wear on our vibratory barrels.

Attention: A vibratory tumbler is the wrong tool for polishing large angular rocks.

Of course, you can run your large angular rocks or coarse grit in your vibe, but if you do, then don't complain about your bowl wearing out in a couple of months. We told you what will happen to your hundred-dollar barrel.

Tip #3:   Small Rocks and Rounded Rocks Cause Little Wear

A person tumbling small rocks or stream-rounded rocks in a UV tumbler might be able to use the same barrel for many years without wearing a hole in it. This is because small rocks don't exert much pressure on the walls of the barrel, and rounded rocks don't gouge material from the barrel walls as they are tumbling.

Most wear occurs on the vibratory barrel's bottom, where the rocks drag through excess grit. That's why you don't want sharp pieces of coarse grit down there abrading the bottom of the barrel.

UV-10 barrel to operating level
A UV-10 tumbler barrel filled to operating level with rough rocks and cylindrical ceramic media of various sizes. In Thumler's UV tumblers, if the barrel is only 1/2 to 3/4 full, the stones can be violently shaken by the tumbler. This can cause bruising of the stones, and the stones can hammer in the barrel, causing small particles of the barrel to be spalled off. Excessive noise is also produced.

By filling the barrel to nearly the top of the center pillar, the stones are shaken less vigorously, and the abundant media of various sizes fills the spaces between the rocks. The media cushions the stones during the tumbling. Click image to enlarge.

Tip #4:   Do Not Drop!
    aka... "handle with dry hands"

Accidents account for a lot of the replacement Ultra-Vibe barrels that we sell. If you drop an Ultra-Vibe barrel that is loaded with rocks - even if you drop it gently - there is a really good chance that it will break or crack. That's a really expensive mistake.

So, before handling a barrel, make sure that your hands and the barrel are both dry. Don't take a chance that the barrel will slip out of your hands.

Tip #5:   Don't Tumble a Barrel Less than 3/4 Full

If you fill an Ultra-Vibe barrel only 1/2 full, here's what will happen. Your rocks will not tumble gently and smoothly - they will be given a very vigorous shaking. That vigorous shaking will make the rocks - especially large ones - hammer your valuable barrel. Every hammer blow can cause damage to your barrel. Some will spall off tiny black particles of barrel. Your $100 barrel is getting thinner. And, the noise will be louder than normal operation.

We run our Ultra-Vibe barrels quite full. Will fill them ALMOST up to the top of the pedestal in the center of the barrel. That produces a nice, smooth, quiet circulation of rocks in the barrel... and our money stays in our wallet.

Thumler's UV-18 tumbler
Shown above is a Thumler's Ultra-Vibe 18 vibratory tumbler. One important place to keep clean on all UV tumblers is the foam pad beneath the barrel. Pieces of rock, media, or other hard particles on the pad can wear a hole through the bottom of a barrel. Wipe the pad before each use and look for particles that might be embedded within the pad. Also, avoid placing the barrel on the floor or on a workbench where it can pick up particles that will transfer to the pad.

Tip #6:   Keep Your Base Pad Clean!

Here is another easily preventable situation that can result in a barrel wearing through much more quickly than expected. That is when small pieces of rock or ceramic media become embedded in the foam pad beneath the barrel.

When a loaded tumbler barrel is shaken on top of a sharp piece of rock in the pad, that can quickly wear a thin spot in the barrel, which can eventually develop into a hole or a crack.

It is very important to keep the pad clean and free of debris.

Tip #7:   Clean the Bottom of Your Barrel

Do not place your barrel on a dirty floor or on a dirty workbench, where small pieces of rock or debris will adhere to the bottom of the barrel. When you pick up the barrel and place it on the tumbler, those pieces of rock or dirt will transfer to the foam pad under the barrel. Soon they will be poking through the bottom of your barrel. That is a great way to drill a hole in the bottom of your barrel or produce an injury that will develop into a hole or a crack.

Best practice is to keep the workplace clean, and wipe any debris from a dirty pad or dirty barrel before placing the barrel on the tumbler.

Tip #8a:   Tumble Rocks in a UV Industrial Model
Tip #8b:   Tumble Brass in a UV Standard Model

We sell three models of vibratory tumblers by Thumler's Tumblers that are designed for rock tumbling use. They are the UV-10,   UV-18,   and UV-45. These three machines have working capacities of 10, 18, and 45 pounds, respectively. The UV stands for "Ultra-Vibe".

How to tell the difference between the "industrial" and "standard" models.

compare UV-10 Industrial and UV-10 Standard Models
In this photo you see an Industrial UV-10 (left) and a Standard UV-10 (right). If you have one of each version side by side, it is easy to see the differences. If you do not, it is important to know what to look for to ensure you are purchasing the proper machine.
The UV-10, UV-18, and UV-45 are available in an "industrial" model and a "standard" model. The "industrial" model is made for tumbling rocks. It has a heavy polyethylene barrel, heavy-duty springs, and a powerful motor. It is specially built for rock tumbling. The barrel that comes with the industrial model has a blue stripe around it.

The "standard" model is intended for light-duty cleaning and polishing of brass ammunition casings. It should not be used as a rock tumbler. Why? The barrel is very thin and the motor is light duty. The barrel that comes with the standard model has a yellow stripe around it.

Make sure you purchase the "industrial" model if you plan to tumble rocks, because the standard barrels will have a very short life if used for rock tumbling. We only sell the industrial models on this website.

How to tell the difference between the "industrial" and "standard" models.

Tip #9:   Don't Over-tighten the Wingnuts

The bowl of the Thumler's UV-10 Tumblers are held down on the base with a small wingnut. Also, the lid is held down on the bowl by another small wingnut.

When you tighten these wingnuts, please turn the wingnut until it makes a snug contact with the bowl (or the lid). Then tighten just a tiny bit more. Remember that the bowl and the lid are made out of plastic! So, turn them until they are snug and then just a tiny bit more. It would be easy for a strong person to over-tighten the wingnuts and crack the bowl or crack the lid.

Tip #10 through Tip #13 Are for Uncle Tom's Lot-O-Tumbler

Single Lot-O Tumbler
Photo of the Lot-O-Tumbler Single with a hard rubber barrel. These barrels are darn near bulletproof - but we hear about humans ruining them all of the time.

Lot-O-Tumbler Barrels

The Lot-O-Tumbler Single and the Lot-O-Tumbler Twin both use the same four-pound capacity barrels. They are made from thick rubber - much like the rubber that is used to make tires.

We have been using our Lot-O-Tumbler Single regularly since 2010, and the barrel shows no signs of wear. These barrels are extremely durable. We have never heard of one wearing thin. We have never heard of one breaking. We sell very few replacement barrels for the Lot-O-Tumbler.

However, we often hear about humans ruining their Lot-O-Tumbler barrel. Here's how to prevent that from happening...

debris in the well
Looking into a Lot-O-Tumbler barrel. In the bottom you can see a few pellets and other debris stuck in the well. There is no need to pry this material out of the well. That is one of the most common causes of barrel damage. Just rinse the barrel thoroughly and it will not cause a problem.

Tip #10: Don't Pry the Well!

The operator looks down into the barrel and sees a tumbled stone or a couple pieces of ceramic media stuck in the small cylindrical well in the bottom of the barrel (see accompanying photo). Small pieces of rock and ceramic media tend to get stuck in that well, and some people feel an urgent need to grab a big screwdriver and pry that stuff out.

Please resist that urge!

Prying in that well can cause the barrel to leak where the cylindrical well meets the curvature of the barrel.

If you allow a few pellets or tiny tumbled stones to remain in the well, they will not hurt a thing. Just rinse the barrel thoroughly and get on with your tumbling. It's not going to cause a problem.

Tip #11: Proper Storage

The second vulnerability that Lot-O-Tumbler barrels face is the same as any other rubber product: they can be damaged by temperature extremes and exposure to direct sunlight. So, don't store them in cold or hot areas - such as an attic, a hot shed, or an unheated garage. Prolonged storage in extreme temperatures or prolonged exposure to direct sunlight will cause the rubber to harden and crack.

Tip #12: No Contact With Grease or Oil

The third vulnerability of Lot-O-Tumbler barrels is in exposing them to grease, oil, or other solvents that might attack the rubber. All three of these vulnerabilities are easy to avoid.

I believe that Lot-O-Tumbler barrels are darn near bulletproof, but humans can easily ruin them. My Lot-O-Tumbler barrels might be in use years after my funeral. :-)

Tip #13: Don't Apply Force to the Barrel

Many people have a huge temptation to force the Lot-O-Tumbler barrel deep into the frame. Please be gentle. And, please know that just pushing it into the frame until it is snug is all that is needed.

If you need to become a gorilla to extract the barrel from the frame, then you probably used too much force jamming it deeply into the frame. I learned to suppress my compulsive behavior of forcing the barrel way down into the frame. It has not popped out of the frame a single time.

Take a close look at your Lot-O-Tumbler barrel. There is a seam in the rubber right at its point of maximum diameter. If you are always fighting to force your barrel deep into the frame and fighting to pull your barrel out of the frame, one day you might notice a smear of rock slurry on the side of the barrel. That is the first sign that your barrel is leaking. Go easy on that barrel. Save your energy for other things.

Happy Tumbling! Authors

Hobart King Hobart M. King has decades of rock tumbling experience and writes most of the articles on He has a PhD in geology and is a GIA graduate gemologist. He also writes the articles about rocks, minerals and gems on