Tumbling Tutorial

These are some of the more interesting rocks that are going into the tumbler today. These are all Crowley Ridge agates. The banding usually comes out really nice after tumbling. Sometimes the more crystalline areas do not take a shine like I would like. I have a fix for that though. Stay tuned! 😊

For stage one, I put one tablespoon of grit per pound of rocks. This is a three pound tumbler so I use 3 tablespoons of grit. Stage one grit is 60-90 silicon carbide. I also add 2 tablespoons of regular non-clumping kitty litter. The kitty litter is just clay. It thickens the water mixture (slurry) and helps carry the grit while tumbling. 

I don’t weigh my rocks or really measure amounts. Some people do. I have not found the need to be precise. We are not baking a cake 😄. Also, you may read that grit needs to be added after the rocks. Not true. It doesn’t matter. The tumbler will mix it all up no matter what order you loaded the barrel. 

Next I added the rocks I wanted to tumble. This is where you take a good look at how full the barrel is and make some decisions. As I stated above, this load had two small problems. The barrel wasn’t 3/4 full and there wasn’t enough variety of rocks. It needed more smalls. 

The next step is to add water just to the top layer of rocks. Do not cover your rocks. If you overfill, your slurry will be too thin and you won’t get good tumbling action.

I like to use very warm water. It creates a little vacuum and helps the lid stay on.  I’m not sure that’s necessary but that’s what I do.

Now put the lid on and place the barrel on your tumbler. 

Pour the contents of the barrel into your colander. If it is winter and you live in a cold weather climate, you can do this step inside over a 5 gallon bucket. The green separator is made to fit on a bucket perfectly. 

Rinse the rocks of grit and slurry with water. You will see in the photo some of the rocks still have a little slurry in cracks and points of the rocks. We will take care of that soon.

After rinsing the rocks, be sure to take an old toothbrush or denture brush and scrub the inside lip of the barrel to clean the slurry from that area. If it’s not cleaned out, it could prevent a tight seal of the lid and can also contaminate the next stage. 

Put the rocks back into the barrel with about 2 tablespoons of borax. I use 20 Mule Team borax which is found on the laundry soap aisle of the grocery store.

Add water to the top of the rocks and let roll on the tumbler for at least 1 hour. This will clean the rocks and the tumbler barrel for the next step. This photo was taken after a borax wash and clean water rinse.

Note: Some people scrub each rock with a toothbrush to clean them. I’ve never found that necessary. 

I let these rocks dry somewhat to show you some imperfections. The areas on the rocks circled in red are indicators that the rocks are not ready for stage two grit. There are still cracks and rough areas.

As I stated earlier on this page, I almost always do stage one at least twice. (The exception would be for rocks which are much softer. They don’t need as much time in stage one.). I put these rocks back in the barrel with 60-90 silicon carbide and a couple tablespoons of kitty litter. Fill to  top of the rocks with water and roll for another 7-10 days.  

Here is stage two right off the tumbler. The slurry is nice and thick. I can see more rock has been worn away by how low the material is in the barrel.

I pour the contents of the barrel out to begin the washing process. This is just like previous steps.  

Don’t forget to clean the barrel ledge with a toothbrush at this time. 

After rinsing, I put these with a little borax and water for a quick tumble to give them a good cleaning. I poured off the borax water and rinsed them clean after an hour or two. 

I circled the ones that I think will be very interesting when finished. I can’t wait for this set of rocks to be completely done. There are some beauties in here.

I put these back in the barrel with 2 heaping tablespoons of stage three grit (500 grit silicon carbide) and water to just under the top layer of rocks. I don’t use kitty litter after stage 2. I’ll let roll for 10-14 days. 

March 20, 2021

Yikes!  I forgot about this barrel!  It tumbled about two weeks longer than I usually run in the polish stage. I guess this will be a bit of an experiment.

I took the barrel of Aluminum Oxide off the tumbler. You’ll notice the liquid looks black.  That’s just on the top layer of foam. The liquid under the foam is white.

After the polish stage, I pour the rocks into a strainer which is over a cheap juice pitcher. Then I pour water over the rocks. I reserve the polish/water and set the pitcher aside. I then rinse the rocks thoroughly. 

Now it’s time for another borax tumble to remove the residual polish. Put a couple teaspoons of borax in the tumbler barrel with rocks and water. Let run for about an hour.

🌟A side note about the used polish: I put the pitcher of water and polish off to the side for several days so the polish settles. When you see a layer of water on top of the polish, you can pour off the water or suction it off with a turkey baster. I allow the polish to dry out and save it in a jar to be used again and again. 

The rocks were tumbled for a couple hours. One hour is enough but I got busy and forgot.  I poured these over a pitcher to capture the borax water. I don’t drain the barrel over grass because borax will kill vegetation. by pouring into an old pitcher I can later use the liquid to kill weeds in cracks in the sidewalk. You can pour this down the drain if you like.

I rinsed the rocks in a colander then put them back in the barrel with about two tablespoons of a grated bar of Ivory soap and warm water to further burnish. This will be tumbled for up up to a day. There are differing opinions about the time for Ivory wash. Some do this for a few days. I’ve tumble with ivory as little as an hour and felt it was sufficient.

🌟A note about Ivory soap: It’s important to use a pure soap. I’ve read some use Fels Naptha or Zote Soap but I haven’t tried those yet.  Ivory is quite economical and readily available so I’ve been sticking with that.

As far as using Ivory, you can do one of three things. You can leave the bar whole and cut slivers of the soap into the barrel. It’s also easy to use a grater or zester and grate directly into the barrel. The last way to use Ivory is my favorite. Put ivory soap bar into the microwave for 30 seconds at a time and it will fluff up. When it’s cool, crush it up with your hands and it will form a powder. Put the powder into a jar and use the soap powder for burnishing as needed. 

🔆🔆 Update as of 12/29/2023:  I no longer use Ivory soap to clean out after each stage. I now only use a borax wash of about 30 minutes. I wash the barrels and lid with a denture brush and then put a couple tablespoons of borax with water and rocks after each stage.