Can Rock Tumbler Grit Be Reused? You Should Know This

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Calling all rock tumblers! Do you feel like you are throwing away perfectly good grit? The price of everything is rising, and tumbling grit is no exception. In an attempt to save money, you may be wondering how to go about doing that. Is reusing Tumbler grit the answer?

Rock tumbling, for some, is a hobby or passion. And, for others, it is a career. Either way, materials can be costly. To save money, some people will reuse their Silicon Carbide grit. While this may seem like a good idea, it costs more and is less effective. Plastic filler pellets can be reused, though.

Let’s get down to the nitty-gritty of rock tumbling. Should we, or shouldn’t we, reuse our tumbling grit? That is the question.

If you want to check out the best grits for rock tumbling, you can find them here (Amazon link).

Rock Tumbling Grit

What people love about rock tumbling is taking something as simple as a rock and turning it into a shiny piece of art. The great thing about rock tumblers is that they do most of the work for you. The finished product makes great jewellery or display pieces.

Just toss in your rocks and a few scoops of grit, add some water and hit the power switch. The rocks are typically purchased as raw or rough stones.

To get them polished and looking pretty, it is going to take some serious scrubbing. That’s where grit and the constant motion come into play.

Grit is a man-made material called Silicon Carbide. This media has been used as an abrasive since 1893. Used for things like sandblasting, waterjet cutting, and rock tumbling.

Once the grit has been tumbled around with your batch of rocks for a cycle, it is filled with particles of rock, dirt, and other foreign materials.

Most experienced tumblers would agree that while they would love to reuse the tumbling grit, they won’t do it. It is not worth it to risk it. Reusing grit will not harm your tumbler.

However, it can damage the next batch of rock. Plus, it isn’t the same consistency as when it is first mixed with water.

Reusing Rock Tumbler Grit

Does it hurt anything if you reuse tumbling grit? It could damage your rocks due to small particles of precious rocks that were left behind. When you reuse rock tumbling grit, this happens.

While you may be trying to save money or save the planet by reusing grit, what is actually happening is that your tumbler has to work twice as long when it is filled with recycled grit.

So, if we stop to put it into perspective, that is more money spent on electricity. And, also more wear on your machine.

Reusing grit is not a common practice in the rock-tumbling community. However, it does happen. So, you may encounter experienced tumblers who have been reusing grit for years.

They rinse the slurry and let the water evaporate or dump it off. Then, reuse the grit the next time they tumble.

One thing that can be reused is the plastic pellets that are used for filler if you do not have enough rocks to make a full barrel.

Though you can reuse the pellets, they should be used with the same size grit every time to prevent cross-contamination. Rinse them well to prevent grit from hardening onto them. Air-dry the pellets and label them before you pack them away.

BTW: Do you want to know more about rock and mineral identification? The books listed below are the best ones you can find on the internet (Amazon links):

Rock Tumbler Grit Substitutes

Looking for a less expensive rock tumbler grit? Or perhaps a substitute material that is more budget-friendly?

While the thought may have crossed your mind to grab a pound of sand from the sandbox in your backyard to try in your tumbler, you can forget that idea.

The granules all need to be the same size, shape, and type. And, to compare every grain of sand in a one-pound bag is next to impossible.

The only things recommended for use in your tumbler are water and Silicon Carbide grit, specially designed for tumbling rocks. Not beach sand, nor salt, or kitty litter.

Silicon Carbide is special because the particles are hard enough that they won’t get rounded during tumbling. This may be one reason that people believe grit to be reusable.

Your best bet is to buy in bulk and to shop around. Just because you have found a brand you like doesn’t mean you are currently getting the best price out there.

Another trick of the trade is to buy a less expensive grit for the first step and a more premium brand for the polish stages.

TIP: Have you ever thought about using sand for tumbling? It is not the best idea, but sand can be great as a pre-grit. Read more about this option:
Can You Tumble Rocks with Sand? Everything You Need to Know

Proper Grit Disposal

Do not rinse grit down the drain. As wet grit dries out, it hardens quickly and becomes cement-like. Dried grit will ruin your plumbing and your day.

The most popular way to dispose of used water, slurry, and grit particles is actually to throw them out the door. Dumping residues in your driveway, garden, or woods behind your house.

Remember, this is a man-made substance. And, while many people dump their grit in the driveway or garden, the Silicon Carbide can get eaten by animals or soak into the ground.

Rotary Tumbler vs Vibratory Tumbler

The two main types of rock tumblers are rotary & vibratory. You can probably guess the main difference between the machines by name.

Can you reuse grit in either of these tumblers?

It is not recommended to reuse grit in either style of the tumbler. However, the vibratory tumbler does use less grit than a rotary tumbler. So, using a vibratory style would reduce how much grit you buy.

Rotary – The more popular/common of the two main types of tumblers. The rotary tumbler uses about 2 TBSP of grit per pound of rock. The tumbling cycle is typically 7-10 days. Rounds the rocks out.

Vibratory – The vibratory tumbler uses about half the amount of grit and works in less than half the time of a rotary tumbler. Produces high shine. Rock does not become rounded but keeps the original shape.

TIP: I’ve written a complete guide on the differences between rotary and vibratory tumblers. Find out more in the article below:
Rotary vs Vibratory Rock Tumbler: Which One To Buy & Use

Top Tips for Using Tumbler Grit

In addition to using fresh grit every tumble, here are a few more tips on getting the most for your time, effort, and money.

You need to keep it separate.

For those that use a rotary tumbler, try using separate barrels for the polishing stages. Or a different barrel for each stage and each level of grit. This goes for vibratory tumblers, as well.

Using separate barrels eliminates the need to deep clean a single barrel between steps. If you do not clean between steps, your rougher grit can carry through to the following stages, possibly creating scratches.

A variety of sizes

It is recommended that the same type of rocks tumble together. Instead of type, you can tumble rocks together that are similar in hardness. Tumbling stones together in various sizes will give you more friction (in a good way.)

Use your water pick.

Cleaning rocks between steps is one of the most important parts of rock tumbling. A water pick works wonderfully for getting into any areas where grit may be stuck.

Use two tumblers

Here’s your solution for those who enjoy the roundedness you get from a rotary tumbler but with the process being shorter. Complete step one using a rotary tumbler to get the rounded effect. Then, use a vibratory tumbler to speed up the rest of the steps.

You can tumble more than once

Re-tumble rocks as many times as you like. The more you tumble them, the smoother, less pitted, and higher shine they will have.

Try out this experiment for a deeper dive into the educational side of rocks.

The Key Takeaway

Unfortunately, we are really not able to reuse our tumbling grit. However, plenty of tips above help you get more out of rock tumbling. Try out some of these tips to see how they work for you. Happy tumbling!

TIP: Rock tumblers use various types of grit in the multiple stages of the rock tumbling process to shape, smooth, and polish the stones. Find out everything you need to know about tumbling grit in the article below:
Rock Tumbling Grit: Usage, Types, Disposal & Substitutes