Rock Discoveries

Rock Tumbling: Essential Supplies and Techniques for Stunning Results

Rock Tumbling: A Beginner’s Guide to Supplies and Techniques

If you’re looking for a fun and rewarding hobby that allows you to create unique and beautiful pieces of jewelry or dcor, rock tumbling may be just the thing for you. Rock tumbling involves placing rough rocks in a rotating container with abrasive grit to grind and shape them over time.

This process produces polished and smooth stones that can be used for various purposes. In this article, we’ll discuss the essential supplies and equipment needed for rock tumbling, with a particular focus on rock tumbling grit, polishing grit, tumbling media, and oil.

Supplies and Equipment Needed for Rock Tumbling

Before you start rock tumbling, you’ll need to gather the necessary supplies and equipment to ensure you get the best possible results. Here are the key items you’ll need:

Rock Tumbling Grit

Rock tumbling grit is a granular substance made of synthetic silicon carbide that comes in various grit sizes. The purpose of the abrasive grit is to remove rough spots, smooth edges and shape the surface of the rocks.

The longer the rocks are tumbled, the smoother they become. In general, it’s best to start with coarse grit and work your way up to fine grit.

Coarse grit is excellent for rough surfaces, while fine grit is ideal for the final stage of polishing. There are several types of rock tumbling grit available, such as silicon carbide grit, beach sand, and aluminum oxide.

Each type of grit has its advantages and disadvantages, depending on your needs.

Polishing Grit

Polishing grit is a powder that you use after using the rock tumbling grit. The polishing grit is typically made from aluminum oxide and helps smooth the surface of the rocks.

After the rocks have been tumbled at the appropriate grit, polishing grit can be added for a final finishing polish. A common type of polishing grit is the Rapid Polish, which is a blend of aluminum oxide and tin oxide.

Tumbling Media

Tumbling media is the substance that fills the barrel and cushions the stones as they rotate. There are two main types of tumbling media: ceramic tumbling media and plastic pellet tumbling media.

The ceramic tumbling media is cylindrical and reusable, making it perfect for vibratory rock tumblers. On the other hand, plastic pellet tumbling media is often used with rotary rock tumblers.

These media are small, affordable, and reusable.

Oil for Rock Tumblers

Another essential item for rock tumbling is oil, which serves to lubricate the bearings and motor. WD-40 3-in-1 Motor Oil is a popular option to use in rock tumbling as it lubricates and protects the bearings in the tumblers.

What is

Rock Tumbling Grit? Rock tumbling grit is a granular substance made of synthetic silicon carbide.

It is used to grind and shape rough rocks into smooth and polished stones suitable for jewelry or as decorative pieces. The purpose of rock tumbling grit is to remove unwanted bumps and rough edges from the rocks.

The longer the rocks are tumbled with the grit, the smoother they become. Generally, it is best to begin with coarse grit and use finer grits as the tumbling process progresses.

Grits for Rotary Rock Tumblers

If you’re using a rotary rock tumbler, there are several grits to choose from, each serving their own purpose. Coarse grits are often used initially to remove rough areas from the stones.

Medium grits follow up to remove any scratches and produce a smooth surface that is ideal for final polishing. Finally, fine grit is used to polish the rocks to a glossy finish.

The sizing of rock tumbling grit is based on the mesh size, which refers to the number of openings per inch in a screen. Generally, grinding requires fine or medium grit while polishing requires a finer grit.

Alternative Grits and their Drawbacks

While silicon carbide grit is the best choice for rock tumbling, beach sand can also be used in a pinch. However, beach sand is often rounded and less abrasive than synthetic silicon carbide grit, resulting in longer tumbling times.

It is essential to note that beach sand may contain contaminants such as salt that can damage the stones during the tumbling process. Therefore, it’s best to avoid using beach sand unless you’re entirely out of silicon carbide grit.

In conclusion, rock tumbling is a fascinating and enjoyable way to create beautiful stones that you can use for decoration or jewelry-making. By gathering all necessary supplies and equipment, especially rock tumbling grit, you can achieve impressive results with your rock tumbling activities.

Remember, finding the right balance between coarse and fine grits and using high-quality polishing grit will ensure a successful and efficient rock tumbling process. How to Choose Tumbling Grit,

Polishing Grit, and

Tumbling Media

Choosing the right tumbling grit, polishing grit, and tumbling media is essential to achieving the desired finish on your rocks.

A few factors to consider include the rock’s hardness, the type of tumbler being used, and the level of finish you want to achieve. In this section, we will explore some of the best grits and media types to use in different situations.

Factors to Consider

One of the most critical factors when selecting tumbling grit is rock hardness. Harder rocks require more abrasive grits to polish, while softer stones will become too smooth with excessively gritty polishes.

The desired finish is another consideration, as some grits will produce smoother finishes than others. The type of tumbler being used also impacts the selection of grit because rotary tumblers can accommodate larger grit and media while vibratory tumblers need small-grain sizes.

Lastly, the filler material in the tumbler media can affect the final product. For example, porcelain media will grind rocks faster than plastic media but is significantly louder.

Recommended Grits and their Uses

For Vibratory Rock Tumblers

Polly Plastic Grit is an excellent option for vibratory rock tumblers. These grits have a longer shelf life and can be used for multiple applications.

Coarse grit is perfect for smoothing out rough edges, while medium grit can help shape rocks. For finishing, use fine grit.

Typically, Polly Plastic grits come in sizes ranging from 800-1200 microns.

For Rotary Rock Tumblers

Aluminum oxide polish is a popular choice for rotary rock tumblers and produces a glass-like finish. Rapid polish is another option that offers quicker results, making it ideal for beginners or those that do not have the time for a more extended tumbling process.

Rapid polish can produce impressive results in just one to two days, whereas typical polishing requires up to two weeks. Benefits and Characteristics of

Tumbling Media

Tumbling media helps to cushion the rocks as they tumble, which prevents chipping and damage.

Media also produces friction which results in a smooth and polished stone. Different types of media are available in various sizes, shapes, and materials, including plastic or silicone pellets and ceramic or metal media.

The size of the tumbler determines the size of the media, so ensure to check the manufacturer’s recommendations for proper use.

Maintaining your Rock Tumbler

Regular maintenance of rock tumblers keeps them in good working condition and prolongs their life.

Lubrication is the most important component of proper maintenance.


The motor and bearings in the tumbler require lubrication to operate at peak efficiency. WD-40 3-in-1 motor oil SAE 20 is an excellent option for lubricating your tumbler motor and bearings.

Oiling ports allow you to apply oil to the necessary components of the machine. Easy Steps for

Maintaining your Rock Tumbler

To keep your rock tumbler running smoothly, you should clean and oil it after every use.

Simply follow these steps:

1. Clean the Tumbler: Before applying lubricant, use a damp cloth or brush to clean the drum’s interior.

Be sure to remove any debris or residue before applying oil. 2.

Apply Oil: Apply a few drops of lubricant on the bearings and motor. Always apply the oil from the top of the bearings and motor to encourage it to flow down through the unit.

3. Turn the Driveshaft: Spin the drive shafts slowly to distribute the oil evenly across the lubricated parts.

In conclusion, choosing the right tumbling grit, polishing grit, and tumbling media is essential for getting the desired results from rock tumbling. You should always consider the rock’s hardness, your tumbler, and the final finish you want before selecting your grit and media.

Regular maintenance of your rock tumbler is also vital for its longevity and proper function. By following these guidelines, you’ll be able to create beautiful, polished stones that you can use for various purposes.

In conclusion, rock tumbling is a fun and rewarding hobby that allows you to create beautiful, polished stones suitable for various uses. To achieve excellent results, you must choose the right tumbling grit, polishing grit, and tumbling media, and maintain your rock tumbler regularly.

By considering the factors discussed in this article and using the recommended grits and media types for your situation, you’ll be able to produce stunning works of art that you can be proud of. Here are some FAQs to address common questions or concerns you may have:


Can I substitute beach sand for rock tumbling grit? It is not recommended to replace rock tumbling grit with beach sand as it may contain contaminants and have a more rounded and less abrasive material.

2. How often should I clean and oil my rock tumbler?

You should clean and oil your rock tumbler after every use to ensure it remains in good working condition and prolong its life. 3.

Can I use ceramic tumbling media in a rotary tumbler? Yes, ceramic tumbling media can be used in a rotary tumbler and are especially useful for making larger rocks smooth.

4. What should I do if a rock breaks during the tumbling process?

If a rock breaks during the tumbling process, remove it from the barrel and discard it. Additionally, check to see if any debris is stuck in the tumbler and clean it before resuming tumbling.

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