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  Rock Tumbler Instructions & Tips:  Secrets to Getting a Glass-Like Polish on Your Tumbled Stones!  Rock Pick Legend Co. is a Full Service Rock Shop Specializing in Rock Polishing with Hobbyist & Professional Rock Tumblers:  Covington's, Lortone, & Thumler's Brands

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Photos of How to Change Your Rock Tumbler Grit--
Actual Operating Tumblers Pictured!

Important Rock Tumbler Starter Tips

* Thoroughly clean the barrel and all rocks between steps to remove all traces of grit or polish.  Reduce the time and effort for cleaning by buying a separate barrel for the polish stage.

* Fill each barrel about 2/3 to 3/4 full.  An improperly filled barrel will lengthen the rock polishing time.

* Add plastic pellets during the pre-polish and polish stages.   This helps to cushion the stones and reduce chipping.  This is especially important for soft material.  Only reuse pre-polish pellets in pre-polish and polish pellets in polish.

Basic Rock Tumbling Instructions for Hobbyist Brand Rotary Rock Tumblers (Lortone, Thumler's, Covington):

1. Fill the rock tumbler barrel 2/3 to 3/4 full of rocks.
2. Add water to just below the top of the rocks (so you can see it between the rocks, but not covering the rocks).
3. Add grit. (Grit is listed in tablespoons.)   

Barrel Size Step 1 Step 2 Pre-Polish Polish
1.5# 4 4 6 6
3# 4 4 6 6
4.5# 8 8 10 10
6# 10 12 12 12
12# 20 20 25 25


4. Let each step run 7-10 days.
5. Make sure there is no grit transferred from one step to the next.

Expanded (more detailed) Rock Tumbling Instructions for Hobbyist Brand Rotary Rock Tumblers:

*Fill the barrel ¾ of the way full with rock.
*Add water to the level of the rock in the barrel.
*Add 4 tablespoons of the Step 1 grit.
*Close the barrel and let it run for 5-7 days.  We recommend choosing a day of the week and changing it the same day every week.
*At the end of the 5-7 days, take everything out and wash it--preferably outside.  It will not hurt your grass, animals, or plants, however it can cause your drain pipes inside to clog.

*Put the rock back into the barrel.
*Add water to the level of the rock in the barrel.
*Add 4 tablespoons of Step 2 grit.
*Close the barrel and let it run 5-7 days.
*At the end of the cycle take everything out and wash it.
*Put the rock back into the barrel.
*Add water to the level of the rock in the barrel.
*Add 6 tablespoons of Step 3 grit.
*Close the barrel and let it run 5-7 days.
*At the end of the cycle take everything out and wash it.

*Put the rock back into the barrel.  You should realize it is about half full of rock now even though you started with it ¾ of the way full.
*Add water to the level of rock in the barrel.
*Add plastic pellets into the barrel until it is back to ¾ of the way full.
*Add 6 tablespoons of Step 4 grit.
*Close the barrel and let it run 5-7 days.
*At the end of the cycle take everything out and wash it.

At this point you should see very shinny rocks!  The following last step is 100% optional.

*Put the rock back into the barrel.
*Add water to the level of the rock in the barrel.
*Add 2 tablespoons of dish soap flakes to the barrel.
*Close the barrel up and let it run for about 2 – 4 hours.

These instructions work for our 4-Step Grit Kit.  You can use them with any hobby quality tumbler and any grit kit that is comparable.  These instructions will not work for rock tumblers and grit kits that use pre-rounded rock, Tripoli polish, or other major variations in components.

THERE'S MORE!

Three Easy Steps to Perfectly Polished Stones Using your Rock Tumbler
Tumbling is a fun and easy hobby to enjoy, and by following a few simple steps you can get excellent rock polishing results most of the time.

The ocean was the first rock tumbler. It rolls stones over stones using sand as an abrasive to smooth and shape them. Modern tumblers use the ocean's example. They roll stones over stones using silicon carbide as an abrasive to smooth and shape them. The ocean takes its time to achieve a beautiful result. Impatience is often responsible for poorly polished stones in modern rock polishing. As you go through the tumbling process, remember to be patient.

Step 1: Stone Selection
You must start with good material to get a good result. Look for interesting rocks, those with pretty colors or interesting patterns. When you have a nice selection of good rocks, it's time to sort them. Because the rocks grind against each other, it is necessary for them to be the same hardness. If you are not familiar with Moh's Hardness Scale, pick up a copy of A Golden Guide to Rocks and Minerals.  When you have your rocks sorted by hardness, eliminate rocks with obvious flaws, such as pitting and weak fractures. If a rock breaks as it is tumbling, it can chip other rocks that have been shaped, causing pitting and a poorly polished batch. Break rocks with fractures on the fracture planes. Use a rock hammer and safety glasses for your own safety. Do not try to tumble rocks with pits. Grit will lodge in the pits, and contaminate the entire rock polishing load from one step to the next. Finally, choose a balanced load. A balanced load is one that contains an approximately equal number of larger, mid-sized, and smaller stones.

Step 2: Cleanliness
A fine rock polish is obtained by preventing contaminants from entering the process. Rinse your rock prior to loading the barrel. Wash the barrel seal and rock very carefully between each step. This is where we see the most mistakes occur. Should a rock break in any step, remove it when you're cleaning your load.

Step 3: Loading the Barrel
It is critical that the barrel always be at least 1/2 full of rock, and never more than 2/3 to 3/4 full of rock. Add your grit. Add water so it is just below the top layer of rock. Add baking soda, or a Tums to prevent gas build up from blowing the lid off your tumbler. As your stones tumble, they will lose approximately 30% of their size. Usually at step 3 or 4 the barrel will drop below 1/2 full. At this point you must use a filler material to prevent the rocks from impacting each other with too much force. We use plastic pellets, which work perfectly for rock polishing. For those of you with a double barrel tumbler, you can solve this problem by starting two batches of rock at the same time. As you move to step 3 or 4, eliminate broken rocks, choose the nicer stones, and move them all to one barrel. You have the option of being more picky.

BONUS SECRET TO AN AWESOME ROCK TUMBLER POLISH: Add sugar to your pre-polish and polish stages. Add approximately twice as much sugar as pre-polish and polish to make the slurry thick, and protect the rock from violent impacting.

With some patience, and these tips and hints, we know you'll soon have glossy, lovely gemstones.

Happy Rock Tumbling!

The previous article is from our Dec. 1998 Rock Polishing Newsletter. Copyright Dec., 1998 Rockpick Legend Co.  All rights reserved.

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Top 4 Tumbling Problems and How to Solve Them:
1.  My stones have more of a matted look, than a gloss.

This is caused by two things, contaminants in the process, or not enough cushioning.  Solve by better cleaning, starting with more rock to reduce need for plastic pellets, or by adding plastic pellets in the later stages.

2.  I followed the instructions and oiled the bushings, but my belt keeps breaking. 

It is important to oil the tumbler bushings periodically with 1 drop of oil.  Any more than that will leak through onto the belt and cause it to stretch and break.

3.  The lid to my tumbler popped off while it was tumbling.

Prevent lid openings by cleaning the seal area well after opening.   Prevent gas build-up from blowing the lid off by adding baking soda or Tums to each stage except the final polish.

4.  Only some stones in my load polished.

This is caused by mixing hard and soft stones.  Only the hard stones will polish in a mixed load.

Bonus:  My tumbler motor burned up on a newer tumbler.

Tumblers are rated by weight capacity.  A 3 pound tumbler will rotate 3 pounds of weight indefinitely.  Many people fail to weigh their load, barrel and rock combined, to make sure it falls within the correct range.  This is the # 1 cause of motor failure.

From our Dec. 1998 Newsletter.  Copyright Dec. 1998, Rockpick Legend Co. All rights reserved.

ROCK TUMBLING HINTS for APACHE TEARS:
When attempting to polish "Apache tears" we have heard of lots of personal "recipes".  Here are some methods you may want to try.

1. In steps 3 & 4, add corn syrup to the load to slow down the action. This thickens the slurry and will keep the Apache tears from scratching themselves.
2. Use cerium oxide as a polish with oatmeal and let it go for several weeks. Do NOT add water in this method. Polish dry.
3. Use a vibrating polisher. These type polishers do not have the harsh action a rotary polisher has.

Q. Can I use the grit over?

A. No. The grit breaks down and becomes useless after about 7 days. The grit is not good for anything and is harmless unless you put it in your drain pipes. Here it will harden into a rock dust-cement. Pour it into an empty milk container and throw it away.

You can, however, reuse the plastic pellets. They can be used about 10 to 12 times before they are not good anymore. Just remember to use them in only one grit. The grit gets imbedded in them and if you use them in a different grit you will contaminate the load.

Getting White Lines Out of Your Tumbled Stones

Often after tumbling rocks, you will notice white lines on your newly polished treasures. These lines are caused by polish getting in small cracks in the rocks.

Sometimes there is nothing you can do to fix this problem. However, you can try a few little tricks to get them out.

First, try putting the rocks back in a very clean barrel after you clean the rocks of ALL polish and any dirt that may have gotten on them. Put water in them as you have for all the tumbling stages.

Instead of putting in polish, put in any soap that doesn't produce suds. Ivory soap flakes work well but have become difficult to find in the stores.

After you have the soap and water in the barrel with your stones, you will want to add CLEAN plastic pellets. Do not reuse the pellets from the polish because they are contaminated with the polish.

Seal up the barrel and let it run for a few hours and check. If the white lines are gone, you are done. If they are not let it go a few more hours. This process can take up to 24 hours. If the polish has not come out by then, it isn't going to come out at all.

I have heard of some people grating up Ivory soap bars with a cheese grater. That seems to be working well. My wife got a little agitated when she saw me headed to the food processor with a bar of soap. You might want to get permission or purchase a cheap cheese grater just for this purpose.

Do not use dish soap, laundry detergent, or even dishwasher soap. They will not work.

As always, feel free to call or email with questions.

Rick, rockshop@rocks4u.com

Why do we provide free info about rock tumblers, rock tumbling, lapidary equipment, rock hammers, rock hounding, fine minerals & other rock hobbies?  We hope you enjoy rocks as much as we do for years to come.  Thank you for your patronage!
Free Info Pages Here:
How Rock Tumblers Work
Choosing The Right Rock Tumbler for You
Rock Tumbler Instructions
Choosing Lapidary Equipment
Lapidary Hints & Tips
How to Drill Holes in Rocks
Rock Hounding Tips and Hints
Dugway, Utah Geode Beds Rock Hounding Site
Gold Hill, Utah Mineral List & Collecting Info
Fine Minerals Cleaning Guide
Utah Minerals Type Locality List
Fossils--Specimen Cleaning Guide
Rock Cycle-- Sedimentary, Igneous, and Metamorphic
Mineral Uses in Everyday Items
Beading a Necklace with Stone Beads--Complete Instructions

Last Updated January 27, 2009.  Copyright © 1998-2009 Rockpick Legend Co.

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Rockhounding Tips | Dugway, Utah Geode Beds | Gold Hill, Utah | Utah Rock Hounding Rules
Fine Mineral and Fossil Specimen Cleaning Guide | Utah Minerals Type Locality List
Rock Cycle Chart | Mineral Uses in Everyday Items
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