National Geographic Rock Tumbler Kit - 3 Lb. Extra Large Capacity Barrel with 3-Speed Motor & 9-Day Timer, Kit Includes Rocks for Tumbling and Rock Polisher Grit, Rock Tumbler for Adults and Kids

The media could not be loaded. I started using the National Geographic 3 lb. tumbler in March of 2021. I’m new to rock tumbling, so as I’ve been getting started, I’ve been studying best practices in hopes of maximizing my results.*** Edit *** I like this tumbler so much, I bought a second one. ***/Edit ***This tumbler is extremely well-made. The base, which includes the motor & control panel, is very sturdy. The barrel is exceptional, in that it is larger than other 3 lb. capacity tumbler barrels, and has a very effective sealing mechanism to prevent leaks. There is an extra drive belt included, for when the original belt wears out, or breaks. The overall operation of this unit is smooth, with minimal vibrations. Most of the sound comes from the motor, as the material of the barrel tends to absorb the sound of the rocks tumbling around inside. On speed 3 (the fastest speed), I measured 65 dB right next to the tumbler. Since a rock tumbler has to run 24 hrs. a day, seven days a week, it’s advisable to have it in a garage or basement, so you don’t have to hear it running. While it doesn’t vibrate excessively during use, there is enough vibration to cause it to creep around on a smooth surface. Best to set it on a rubber pad, or otherwise block the base, so it doesn’t creep right over the edge of your work bench.There are two features to this tumbler that make it unique. First, it has 3 speeds, and even the slowest speed is faster than most other tumblers. This must be taken into account when you are determining how best to fill the barrel & how long to run each tumbling cycle. The second unique feature is the shape of the barrel, which is less deep, but larger diameter than other tumbler barrels. The internal volume is actually larger than that of other 3 lb. tumblers. This allows you to put more rocks in each cycle, with more of the weight of the rocks concentrated in a smaller area & tends to increase the efficiency of the grinding action.Faster speeds & more efficient grinding cause the rocks to hit each other more often, which will shape and smooth them in a shorter period of time than with other tumblers. But it also may require you to cushion more fragile rocks (such as feldspar) with tumbling media (such as ceramic pellets) to prevent bruising.Consider the price of this item to be for just the tumbler, with the rocks & grit included for free. The rocks you get are literally a “mixed bag” of all different types & hardnesses. One of the cardinal rules of rock tumbling is to only tumble rocks of the same hardness & durability together in the same barrel. So you don’t want to mix agates with feldspar, for example. Once you separate the included rocks by type, you will find that there aren’t nearly enough rocks to fill the barrel with similar rocks. Best to order 3-5 lbs. of a single type of rocks (search for “tumbling rough” online) so you can fill the barrel correctly for the best results.After a bit of experimentation, I have found that this tumbler produces the best results when the barrel is 3/4 full. This is about 3 lbs., although the weight will depend on the density of the rocks in your barrel. The main consideration should be where the top of the rocks are, compared to the bottom of the lid. By measuring the depth of the barrel, you can easily make a gauge that will represent the correct amount of space to leave at the top. Too many rocks in the barrel will prevent them from tumbling freely, but too few will just bounce around in the barrel, instead of sliding & grinding against each other. If your barrel is too heavy, it will cause the motor to shut down & you will have to follow the steps in the instruction manual to get it working again. I have routinely filled the barrel with 3 lbs. of dry rocks (plus water & grit) without having it shut down. I have also found that I get the best results when I include some ceramic tumbling media to fill the gaps between the rocks (this helps to carry the grit for more efficient grinding & also to cushion the rocks.)The included grit & polish packets are insufficient to produce good results. Buy some bulk grit & polish from a rock shop (there are several online.) You will want 60/90 Silicon Carbide for stage 1 (about 4 tablespoons per load.) You will use much more of this than any other grit, as stage 1 can take several cycles to shape hard rocks, such as agate & jasper. Stage 2 requires 120/220 Silicon Carbide (about 4 tablespoons per load.) You will probably need to run one or two cycles in stage 2, until the rocks are smooth. Stage 3 requires 500 grit (either Silicon Carbide, or Aluminum Oxide) - about 4 tablespoons per load. This stage will probably only take 1 cycle & the rocks will start to show a slight gloss & feel really smooth. Stage 4 requires Aluminum Oxide polish (about 3 tablespoons.) This will generally be a single cycle (until the rocks are shiny when dry.) I have never used the included foam cubes. Instead, I run a burnishing cycle using 4 tablespoons of borax powder & a squirt of Dawn dish soap. (All stages require just enough water to almost cover the rocks.)I run stage 1 on speed 3 (fastest) in 4-day cycles. Empty the barrel, rinse the rocks into a bucket, & examine them. If all of the edges are rounded, set the rock aside for stage 2. If there are still rough edges or large pits, you will need to put the rock back into stage 1. Because most of the grinding happens in stage 1, you will have to add more rocks in each cycle to keep the barrel at 3/4 full. This requires a large enough supply of rocks to keep feeding the barrel. Six pounds of rough might yield three pounds of polished stones. When your pile for stage 2 is large enough, you can proceed. This may take a month or more.Once you move on to stage 2, things move faster. I run stages 2-4 at speed 1 (slowest) in 7 day cycles. Use the same process as described above to sort your rocks. When you finish stage 2, there should be no rough spots (usually 7-14 days.) When you finish stage 3, the rocks should feel very smooth & maybe slightly glossy (about 7 days.) If your rocks still aren’t shiny after 10 days in stage 4 (polish), you might consider trying another type of polish (such as Cerium Oxide, or Tin Oxide) for an additional 4 days.This is an excellent rock tumbler that comes with insufficient supplies. My advice is to buy the tumbler, throw out the grit & polish, order your rough rocks and grit/polish from a rock shop, and consider the included rocks as a bonus.There are many excellent resources available online, including YouTube videos & a forum called “Rock Tumbling Hobby.” If you are considering buying a rock tumbler, you should check these out. My most valuable resource has been a book called “Modern Rock Tumbling”, by Steve Hart. It covers everything involved in the tumbling process, with excellent advice for how to get good results.*** Edit ***The motor went out on my tumbler, but I e-mailed [email protected] with a copy of my receipt, and explained the problem. They replied within the hour to tell me that they were sending me a new tumbler as a replacement (no charge.) The new tumbler arrived in two days. Superior customer service!

The rock tumbler works great but the step 4 "final step" grit is NOT the final grit ran for three weeks with the "final grit" and nothing got polished bought a 12000 grit aluminum oxide to finish the polish

I purchased my first Nat Geo 3 Lb Professional tumbler in January. I liked it so much I now have several running and I run them every day. They're easy to fill, clean and are relatively quiet. I especially love the rubber barrel that cushions the rocks while they tumble and are much quieter than plastic or polyethylene counterparts. I've had very nice results polishing many different types of rocks and Mohs hardness levels. It's certainly easy enough to use that kids could enjoy this tumbler but it's also of high enough quality for adult enthusiasts.The first tumbler I purchased stopped running recently and after unplugging it and plugging it back in, it resumed running but much slower and would no longer run on 3 speeds. I sent an email to Nat Geo customer service (on a Sunday afternoon) asking if they could help and got an immediate response. The rep asked for proof of purchase and because it had been purchased within the last year, they sent me a new tumbler at no cost. It arrived THE SAME DAY! On a Sunday no less.That's what I call standing behind your product and excellent customer service. Very impressed!

I'm an adult hobbyist, not a kid or a parent - and this machine seems like a valid option for anyone - so far - I am writing this review the night after receiving it and will update if anything goes horribly wrong.I live near a river and collect rocks, and have wanted a tumbler for a while, but the startup cost seemed a little steep to me however, this kit is affordable for what it contains.The machine is sturdy, with a good sized rubber barrel. I fit about 25-30 rocks of varying size in mine for it's first tumble. It makes noise obviously, but not as much as I thought it would. It kind of sounds like a washing machine. Except, full or rocks. The setup is very easy, there is no assembly required, you literally plug it in, set how many days you want it to run for, and how fast. The instructions provided tell you how long and how fast to do each stage.The rubber lid beneath the metal screw-on top was a little difficult to get off at first, but I'm assuming that is because it was literally vacuum sealed - and it isn't something you want leaking. The kit came with a few tacky jewelry fixtures which might be relevant for a 7 year old but were nothing impressive. A few bags of rocks are also provided - but honestly only about half of mine were viable. Some of them looked cool, but many of the "rocks" were just chipped off pieces or flakes of larger chunks, and were probably too brittle to survive tumbling. Breakage can happen, and rocks shrink a lot with every cycle, so something the size of a quarter might be the size of a penny when it is done. A lot of the rocks I threw in my first batch were from digging around in parks and on river banks.Some notes:- I have no idea if the "Gem Foam" is worth it. I follow several people on social media who tumble a lot, and I have never seen any of them use foam media to polish their rocks. It may just be an unnecessary addition that NatGeo is using to try to make their product seem different.- Additionally, many of the people I follow as well as some of the other customers who purchased this item complain that their rocks do not get shiny. I have read that washing out the barrel and doing a short (3-5 hours) cycle with the rocks and some ivory soap shavings to clean everything between grit stages helps the rocks achieve a good shine.- Also, I have discovered that the polish (the final step) NatGeo provides in this kit and others they manufacture, is...unsatisfactory. A good brand to go with is Polly Plastics for better polish and grit refills.- I have also read that ceramic media can help rocks to tumble better in less time. I do not have any myself but I believe it is something I will try in the future.Tips?- You are going to also want to buy a big cooking strainer and dedicate it to your rocks to rinse them off after each cycle- Don't wash the grit down any sink or tub because it can clog your pipes when it hardens