Any rockhounds out there in TW?

Ill just send my rocks to you to cut

 

The grandson got a rock tumbler last year. It was on all last summer. We didnt have much success. I think a combo of that the tumbler wasnt able to go slow enough and too soft of rocks??? Where learning but still quit a ways to go.

Any input on the best rocks and were to get some? The tumbler was reviewed by the utube guy in Michigan as being too fast, but he still managed some Shiney stones?

Thanks

 

Here's my experience. Rock tumbling seems like it would be easy. Rocks+grit+water+time = shiney rounded rocks. Then reality set in. Suffice to say, the instructions I initially received of using one grit step per week are total bunk. I dont really tumble any more, mostly cabs and flat surfaces, but when I was, here is my formula, assuming you have a rotary tumbler.

General Notes:

• Expect tumbling to take a lonnng time. Patience.
• 1 tablespoon of grit per pound of tumbler barrel capacity.
• Use silicon carbide grit. Softer grits like aluminum oxide don't seem to work as well.
• Use cerium oxide for polish. Seems to work best for all rocks for me.
• Use rocks of all the same approximate hardness - for example, all agates
• Cleanliness between steps is paramount. A little bit of grit can ruin a polish.
• Use ceramic filler pellets if needed to cushion the stones. Otherwise as rock volume decreases due to grinding action, rock bruising (surface chipping) is more likely to occur.

Recipe:

• Fill barrel 3/4 full of rocks. Add ceramic filler pellets if needed. You want a mix of sizes but more smaller ones than larger.
• Add water until it is just below the top layer of rocks.
• Add 70/90 silicon carbide grit. I used 12lb barrels, so minimum 12 tablespoons. You can always use more grit if you want.
• Close up your barrel and start it tumbling.
• Leave it alone for One Full Month. Set and forget.
• Check to see if your stores are nicely rounded and semi polished. Here's the secret - the grit keeps breaking down smaller and smaller so you don't need additional grits other than polish.
• If your stones look good, rinse very well to get rid of all the rock mud. You don't want any sign of rock mud on your stones or the barrel.
• Sort out the rocks that still look too rough and put them back in when you first start your next batch.
• Put your rocks ready for cleaning back in your barrel.
• Add filler ceramics if needed, ideally already with worn rounded edges. You want the barrel to remain 3/4 full.
• Add water and a little Dawn kitchen soap (blue sink stuff).
• Close up your barrel and let run for a day. This super cleans your rocks.
• Clean everything again.
• Now you are ready for polish. Fill your cleaned barrel 3/4 full with cleaned stone and ceramic pellets if necessary. Add polish at 1 tablespoon polish per pound of barrel capacity. Water to just blelow evel of the rocks. Close up the barrel.
• Run tumbler for a week, then check to see if polished. If not, just close the barrel back up with no changes and run for another week.
• One you are satisfied with the polish, rinse everything to get rid of rock mud.
• Run for another day with Dawn/water to do a deep clean.
• Clean everything again and enjoy your tumble polished stones!

Rocks to use:
I suggest starting with agates. Or at least the same kind of rock, not a mix of different types and hardness.

If you want to buy rock instead of collecting yourself, in addition to Amazon, here's a couple places I've done business with:

• https://kingsleynorth.com/lapidary-...a3yEbjl9AQJrhVtXCSJrczRHrJHHZzCxDPq2ugWCdktFo
• https://www.rockshed.com/product-category/rock-tumblers-supplies/crushed-rock-for-tumbling/

-Jon

 

Thanks for the effort! I didn't realize such thoroughly cleaned rocks took that long ill definitely increase time.

So you think not having a real slow tumble isnt a big issue?

I kind of wandered if rinsing a rough cut and adding the next finer was really needed? Maybe adding the next finer to the previous broken down is fine? Definitely long Dawn tumble and on to polish?

Would the small round ceramic or oval ceramic be best? I beleive its a 2 lbs tumbler

 

Yeah, the time it takes caught me by surprise as well. And everyone has a tumble polishing recipe that works for them.

I did try the different levels of grit before I got fed up and just let a batch run on the 70/90 grit for a month. The grit just keeps breaking down so what starts as 70/90 will got to 120, 220, 400, etc as it's left running.

The cleaning run with Dawn for a day (doesnt really need to be longer in my opinion) between the grinding run and polish run is important because any left over grit can leave nice scratches in the batch.

As far as tumble speed - I don't think it's an exact science. There's calculations that can be made based on pulley diameter to determine rpm if you really want. But I would guess any of the commercial units should be within tolerances. That's part of the reason for using ceramic pellets as filler. Helps blunt the dropping force in the barrel to prevent chipping and fractures.

I don't have enough experience with different types of filler pellets to know if there is a difference. This is what I grabbed from Amazon:

$20 5 LBS 1/5" x 2/5" Ceramic Media for Rock Tumbling – Ceramic Tumbling Media for Rock Polisher, Use with Rock Tumbler Grit, Protects Rocks, Reusable, Rock Tumbling Supplies(5mm x 10 mm)

https://www.amazon.com/Tonmp-Pound-...=&hvlocphy=1027744&hvtargid=pla-2281435181738

 

Yes thats the 3/8 pellets plus i have lirrle roound ones. Ran em both just for good measure.(?)

 

Probably doesn't hurt anything to run both. More surface area to have grit rubbing on rocks.