Blue MarbleNational 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!

I love this rock tumbler. I bought two -- one for my grandson and one for myself seven months later. His is still going strong two years later, but mine stopped eight months short of the end of the 2-year warranty period. I inquired about getting a new motor and was sent an entirely new tumbler - base, canister, rocks, grit -- the whole shebang. Free of all charges, including shipping. It arrived the following day. I would not have questioned a replacement charge -- I have used this rock tumbler hard and didn't feel it owed me anything. It's an awesomely hard working tumbler backed by incredibly good service.

It literally is as easy as finding rocks on the ground, filling this thing up 2/3 full, adding some water just to cover the top of the rocks, sprinkle a little bit of powder, drop it on the machine, set the speed and days, and good to go.If you don't want to look for your own rocks that's okay because they give you a bag of red jasper, tigers eye, citrine, quartz, rose quartz, amethyst, and more to tumble for your first batch. The stones they gave looked like they were cut off from chunks used to make jewelry, but nonetheless were amazing to receive. The quality of the rubber barrel is amazing. It is thick and durable feeling. It also really dampens the sound that can be generated from most rock tumblers. The machine has three speeds and can go for the nine days. The back bar has a belt that goes to a motor that runs it. When you put the barrel of rocks on it stops vibrating because of the weight holding it down. I still placed a towel under it to further dampen the noise and all I hear is rocks sloshing and a faint motor hum. If you want to dampen sound further you can put a 5 gallon bucket over it and you won't hear pretty much anything. But I wouldn't want to do that to this machine. It's somewhat a thing of beauty because you know it's contents. And slight entertainment watching it tumble knowing again that you're stones a month from now will be polished and amazing. I mean you can't see the stones tumble because it's not a clear case, but that lets you use your imagination on the stones you put in. How much are they going to get worn down? What designs and patterns will they reveal? How shiny are they going to be? Patience is rewarded with this rock tumbler. I've had it for almost a month and have them on stage four, final polish. They have about a week to go and then they came with some gemfoam cubes for another few days polish. But each time I've pulled them out and rinse them off outside in the yard they look more and more amazing. Do not put any rock grit down your drains. It's a whole bunch of chips and tiny bits of rock that if you pour down your drain will get stuck in the pipes u bend because they're heavier than water. This is not an instant gratification machine. This will take minimum a month if you do a four-stage batch one week per stage.TLDR - large barrel size, dual clamp lid, starter kit comes with stones grit and jewelry stuff, quietest tumbler, just add water.