How To Polish Your Own Rocks using a Rotary Rock Tumbler

by Judy Ellis

A Rotary Barrel Tumbler properly filled with rock, water, and abrasive media, simulates the natural erosion action of water on rocks. Beaches and riverbeds contain rocks and pebbles that are smooth and rounded as a result of moving water and the abrasive sand it carries.

As rocks grind upon one another with constant flowing water and sand in the mix, they begin to round and smooth. The speed of the water and grit in the water determine how long this process takes.

A Rotary Barrel Tumbler significantly speeds up this natural erosion process by consistently rotating and using abrasive media rather than sand.

The rotary action of the barrel creates a swirling motion, the rocks lift up the sidewall of the barrel and then slide and tumble back down the barrel over the top surface of the other rocks and abrasive media.

Golden Rules to Rock Tumbling

1. Garbage in Equals Garbage Out - It is important to start the process with quality rocks, if you start with low quality rocks that have lots of flaws, you should expect a low quality result.

2. Avoid Contamination - You will be using different abrasive media in each step of the process. It is important to thoroughly clean your barrel and lid between steps as to not contaminate finer grit steps with the coarser grit from the prior steps.

3. Be Patient - Quality results take time, don't rush the process. If the edges of rocks aren't as smooth as you'd like during the initial grinding stage, don't hesitate to run them through that step again.

4. Keep Records - Keeping records will help you remember the kind of grit used last, the amount of time you tumbled the rock for and the results.

Initial Tumbler Setup

Step 1: Determine a location to operate. Rotary Tumblers are designed to operate 24 hours a day, for several weeks at a time. Choose a safe location that is accessible, but won't interfere with your daily activities. Do not operate in an outside location. The Barrels contain water, and if frozen, will cause the barrel to become unbalanced, which could cause the motor to overload and damage the unit.

Step 2: Before the first use, and once a month thereafter, put a few drops of oil on the Driving Shaft bearings.

Step 3: Check the V-Belt tension. It must be kept as loose as possible without allowing it to slip on the Pulley. Check before each use.

Step 4: Make sure the exterior of the Rubber Barrel is clean so that it doesn't slip on the rollers. Wipe it with a soapy cloth, then wipe it clean with a damp cloth, and dry thoroughly. Do not use liquid cleaners of solvents.

Step 5: Make sure that the Stop is lightly touching the Barrel Lid. This will prevent the Barrel Lid from rubbing against the housing and will reduce friction.

Step 6: To open the Rubber Barrel, remove the Barrel from the unit and then remove the Knurled Nut and the Washer then remove the Barrel Lid (sometimes it's helpful to use the washer as a pry tool to remove the barrel lid).

You are now ready to select your rocks and load your barrel!!!

Rock Selection

When selecting your rocks it is important to remember Golden Rule #1 "Garbage In Equals Garbage Out". To achieve a high quality result it is important to start with quality rough rock. Use your own judgement here and make notes in your log to learn from your experiences.

Rocks that are porous, should be discarded. They will not polish out to that high quality brilliant shine that you are looking for and may carry grit from one step to another, creating an issue with Golden Rule #2 "Avoid Contamination".

Rocks with fractures will most likely break while tumbling and scratch the other rocks in the batch. If you are able to break the rock at the fracture, the rock can still be used, otherwise it should be discarded.

To achieve the best result, the barrel should be loaded with rock of various sizes (1/4 inch up to 1 inch) and similar condition and hardness.

Rocks with jagged edges will take longer than rocks without, thus both would have different processing times, same with hardness. By selecting rocks with similar condition and hardness, you are selecting rocks that have similar processing times.

Loading the Barrel

Make sure the barrel is clean before loading, remember Golden Rule #2 "Avoid Contamination". It is also imperative to load the Tumbler with the proper amount of materials, or the process will not be successful, and the motor could be damaged.

An under loaded barrel will not lift rocks up the inner side walls allowing the cascading effect. Also, the abrasive material in an under loaded Tumbler will tend to form a slurry and will not be effective. An overloaded Tumbler will not allow the rocks to cascade. Lastly, too much water will cause the abrasives to float and not do their job.

Load the barrel from 2/3 to 3/4 full. More pointed or abrasive rocks or stones will require close to 3/4 full, leaving a 1/2 full barrel when it comes time to polish. If you don't have enough rock to fill the barrel 2/3 full, we recommend filling the remaining volume with plastic pellets.

Note: Make sure loaded barrel isn't over 3 lbs. An overloaded barrel may damage the motor.

Judy Ellis's How To Polish Your Own Rocks using a Rotary Rock Tumbler - Rock Selection, General Education, Tumbling, Tumble, Tumbling Jewelry, Rock Selection

Recommended Abrasive Quantity (3lb. barrel)

Coarse: 4 Tbsp
Medium: 4 Tbsp
Pre-Polish: 4 Tbsp
Polish: 6 Tbsp
Burnish (Liquid Hand Soap): 1-2 Drops
Plastic Pellets (as needed to fill void and especially useful in polishing stages so rocks don't scratch each other).

{Step 1 - Coarse} - Initial Grinding and Shaping

Run Time: 7-10 Days

This step is by far the most important step in the process and sets the stage for the subsequent steps. Fill 3 lb barrel about 2/3 full of rough rock. Then add 4 level Tbsp Coarse Grit and enough water to almost cover the rocks.

Judy Ellis's How To Polish Your Own Rocks using a Rotary Rock Tumbler - {Step 1 - Coarse} - Initial Grinding and Shaping, General Education, Tumbling, Tumble, Tumbling Jewelry, Step 1A

Seal the Rubber Barrel and replace the Barrel Lid, the Washer and the Knurled Nut.

Judy Ellis's How To Polish Your Own Rocks using a Rotary Rock Tumbler - , General Education, Tumbling, Tumble, Tumbling Jewelry, Step 1B

Set the Rubber Barrel on the rollers and turn on the Power Switch. Make sure to check the Lid seal during the first ten minutes to make sure the tumbler isn't leaking.

Judy Ellis's How To Polish Your Own Rocks using a Rotary Rock Tumbler - , General Education, Tumbling, Tumble, Tumbling Jewelry, Step 1C

Remove the barrel after 12-24 hours to release gas build up. Slowly open the Barrel Lid, releasing the small amount of gas that builds up during the process. Check the stones, they should show slightly rounded edges.

Judy Ellis's How To Polish Your Own Rocks using a Rotary Rock Tumbler - , General Education, Tumbling, Tumble, Tumbling Jewelry, Step 1D

Clean the seals and close the Lid. It is important to release the gas, otherwise it will thicken the abrasive slurry. After another 24 hours check again. If the slurry is thickening, add a little water.

Run for one hour and check again. If it is still thick, add some more water. Let the Tumbler run continuously, but check daily. Continue this process for 7-10 days to remove the sharp edges and rough areas. Be patient. This is the most important step. When all of the edges are rounded you are ready for the next step.

Cleaning: Between steps you must clean the Rubber Barrel and stones. Pour off the slurry into a disposable container (such as a milk carton or coffee can) and take care that the stones remain in the Rubber Barrel.

Pro Tip: Warning! Never pour the slurry into your home plumbing system as it will cause damage!

Judy Ellis's How To Polish Your Own Rocks using a Rotary Rock Tumbler - , General Education, Tumbling, Tumble, Tumbling Jewelry, Step 1E

Next, place the stones into a clean container or plastic bag. Fill the Rubber Barrels 1/2 full with water and clean out the remaining slurry and grit. Wipe and dry with a paper towel. To clean the stones, gently slosh them around in clean water and remove them a few at a time checking for breaks or cracks. Discard broken or cracked stones. Place the stones in a plastic colander, or old nylon sock and rinse them completely off. There should be no slurry or grit remaining on the stones.

Judy Ellis's How To Polish Your Own Rocks using a Rotary Rock Tumbler - , General Education, Tumbling, Tumble, Tumbling Jewelry, Step 1F

{Step 2 - Medium} - Smoothing Initial Grind

Run Time: 7-10 Days

Carefully replace cleaned rocks into the Rubber Barrel. If the Barrel is less than 2/3 full, replace lost volume with plastic pellets to help cushion the stones. Then add 4 level Tbsp Medium Grit and enough water to almost cover the rocks. Reseal and tumble.

Judy Ellis's How To Polish Your Own Rocks using a Rotary Rock Tumbler - {Step 2 - Medium} - Smoothing Initial Grind, General Education, Tumbling, Tumble, Tumbling Jewelry, Step 2A

Tumble rocks for 7-10 days, check every 2-3 days and inspect several rocks. When the entire dried surface of the rocks have a matte finish you are ready for the next step. Clean the rocks, barrel and lid using the same process you did after Step 1.

Judy Ellis's How To Polish Your Own Rocks using a Rotary Rock Tumbler - , General Education, Tumbling, Tumble, Tumbling Jewelry, Step 2B

{Step 3 - Pre-Polish} - Prepares Rocks for Final Polish

Run Time: 7-10 Days

Carefully replace cleaned rocks into the Rubber Barrel. if the Barrel is less than 2/3 full, replace lost volume with plastic pellets to help cushion the stones. Then add 4 level Tbsp Pre-Polish Grit and enough water to almost cover the rocks. Reseal and tumble.

Judy Ellis's How To Polish Your Own Rocks using a Rotary Rock Tumbler - {Step 3 - Pre-Polish} - Prepares Rocks for Final Polish, General Education, Tumbling, Tumble, Tumbling Jewelry, Step 3A

Tumble rocks for 7 days, the surface of the rocks should be smooth and have a slight shine. If not, remove any chipped or broken pieces and tumble rocks for 2-3 days more. Clean the rocks, barrel and lid using the same process you did after previous steps.

Judy Ellis's How To Polish Your Own Rocks using a Rotary Rock Tumbler - , General Education, Tumbling, Tumble, Tumbling Jewelry, Step 3B

{Step 4 - Final Polish} - Final Polish of Pre-Polished Rock

Run Time: 7-10 Days

Carefully replace cleaned rocks into the Rubber Barrel. If the Barrel is less than 2/3 full, replace lost volume with plastic pellets to help cushion the stones. Then add 6 level Tbsp Final Polish and enough water to almost cover the rocks. Reseal and tumble.

Judy Ellis's How To Polish Your Own Rocks using a Rotary Rock Tumbler - {Step 4 - Final Polish} - Final Polish of Pre-Polished Rock, General Education, Tumbling, Tumble, Tumbling Jewelry, Step 4A

Tumble rocks for 7 days, the surface of the rocks should have a bright shine and look the same dry as they do wet. If not, tumble rock for 2-3 days more. Clean the rocks, barrel and lid using the same process you did after previous steps.

Judy Ellis's How To Polish Your Own Rocks using a Rotary Rock Tumbler - , General Education, Tumbling, Tumble, Tumbling Jewelry, Step 4B

{Step 5 - Burnishing} - (Optional) Used to Remove Trace Amounts of Residual Polish

Run Time: 2 Hours

Carefully replace cleaned rocks from Step 4 into the Rubber Barrel, add plastic pellets to cushion rocks, 1-2 drops of liquid hand soap and enough water to almost cover the rocks. Dish soap or detergent is not recommended and will cause premature wear on the barrel.

Tumble rocks for about 2 hours, remove and rinse.

Notes to Remember

Pro Tip:
- Always clean Rubber Barrel between steps.
- When polishing or burnishing use plastic pellets (they will wear out during regular use)
- Use a logbook to keep track of each step.
- If starting with stream-worn or smooth stones, you may be able to eliminate the first step.
- Purchase a mineral book which details the selection of stones for tumbling. As you learn about relative hardness of each stone you will achieve greater success by not mixing soft and hard stones.
- Always dispose of material properly.

How to Change Your Belt

How to Change Belt Tension

Materials

WireJewelry Madagascar Stone Mix Rough - Large Natural Gemstones in 3 LB Bag

E6-300R

Lesson Quantity: 1.00 pieces
Purchase Quantity: 1.00 each
Price: $34.82
Gold Club Price: $26.12

Add to Bag

WireJewelry 4 Step Rock Tumbler Abrasive Grit and Polish Kit with Plastic Filler Pellets, 5 Batches

G24-10

Lesson Quantity: 1.00 pieces
Purchase Quantity: 1.00 each
Price: $43.95
Gold Club Price: $32.96

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Tools

WireJewelry Professional Single Barrel Rotary Rock Tumbler with 3 Pound Capacity Drum (2021 Version)

G24-1V2

G24-1V2
Lesson Quantity: 1.00 pieces
Purchase Quantity: 1.00 each
Price: $106.60
Gold Club Price: $79.95

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Optional Tools

WireJewelry Single Barrel Rotary Tumbler, Jewelry and Metal Polishing Kit, Includes 1 Pound of Jewelers Mix Shot and 8 Ounces of Shinebrite Burnishing Compound (2021 Version)

G24-1V2-KITSS

Lesson Quantity: 1.00 pieces
Purchase Quantity: 1.00 each
Price: $159.93
Gold Club Price: $119.95

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WireJewelry Single Barrel Rotary Rock Tumbler Madagascar Mix Starter Kit, Includes 1.5 Pounds of Rough Madagascar Stone Mix and 1 Batch of 4 Step Abrasive Grit and Polish with Plastic Pellets (2021 Version)

G24-1V2-KIT100

Lesson Quantity: 1.00 pieces
Purchase Quantity: 1.00 each
Price: $126.60
Gold Club Price: $94.95

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WireJewelry Single Barrel Rotary Rock Tumbler Madagascar Mix Deluxe Kit, Includes 3 Pounds of Rough Madagascar Stone Mix and 2 Batches of 4 Step Abrasive Grit and Polish with Plastic Pellets (2021 Version)

G24-1V2-KIT300