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Rock Tumbler: Cheap, Yet, Fun And Interesting

Reviewing: Nsi International Inc. The Original Rock Tumbler #635  |  Rating:
cnt24 By cnt24 on
Badge: Advisor | Level: 20 | Children & Parenting Expertise:
Rough Rocks

My youngest daughter is an avid rock collector. Most of the rocks she finds are rough and need polishing. Try as she might, polishing them in the sink, under running water, gets her nowhere. For Christmas, we decided to get her the Original Rock Tumbler kit so she could see how her rocks would look with a little tumbler polishing.

What's Included:

The kit comes with a tumbler tub, turning motor, select rough rocks, various craft items (key chains, necklaces, rings and adhesive), coarse and medium grits, and finishing polish. Everything you need to get started polishing rocks.

The Process:

Rock Tumblers can take up to a month to produce a polished rock. So, if you're interested in doing this, you must have patience. This is not our daughter's strongest point. Perhaps this is why the product is rated for ages 10 to adult.

We had to explain to her that the polishing process takes several steps. Each step consists of an initial rinse, putting selected rocks in the tumbling tub (about a handful), adding the required grit, covering the rocks with water, and tumbling for the specified time. First, you must allow the rocks to tumble constantly in coarse grit for up to four days. Second, you tumble the rocks in medium grit for a couple of weeks. Finally, they are polished in the rock tumbler for a week to ten days, or until you like the resulting polished finish. (If you buy a four-grit replacement grit, the process takes even longer).

Problems Encountered:

Rock tumblers are noisy, this one sounds like a loud electric can opener, so you really need to run it in a place apart from where you hang out. Luckily, we have a detached garage and can let it run there without being disturbed or annoyed. Do not buy one unless you can run it outside of your living area.

We found the tub on the Original Rock Tumbler kit has a leaky seal. The instructions stated there might be some leaking. So, we continued through the steps. The tub is plastic. The top and bottom pieces lock together with a small gasket, notch, and turn system. Perhaps if the pieces screwed together, or the connecting notch went in further to snug up to the gasket, the tub would not leak. The leaking never became overly problematic and usually stopped after a couple of days between the tumbling steps.

The tub not only leaks at the seal, it develops holes over time. After the first tumbling session, we discovered the tub was wearing out and thinning at the peaks of groves in the tub design. We tried strengthening these areas with an epoxy sealant we use on our boat, but the repairs only lasted through two more tumbles before the areas completely wore into huge holes. More tubs are available through NSI International for an extra charge plus shipping and handling.

The kit only comes with enough grit for only half of the rough rocks supplied with the kit. You must buy more grit to finish all the crafts. This information is not on the box. We had to make an extra trip to the store just to finish the supplied projects. The grits can be purchased in various sizes separately. You can also buy better grits for a better-finished product. We found a three-pound package of four-step grit for $30.00, which is enough grit to last through multiple tumbles.

The supplied craft implements are made of cheap plastic. The adhesive does not bond the rocks to the plastic very well. We ended up purchasing better craft supplies at a hobby store to make the crafts more worthwhile and durable.

The Results:

After the initial shock of finding out how much time it takes to polish rocks, our daughter learned she really loves doing it. She is out looking for rocks to polish daily, which is far better than sitting in front of the TV or playing video games.

The Original Rock Tumbler kit could be improved by providing more grit, improving the tub, and including better quality craft supplies. We will use this tumbler until the motor quits working and then buy a better quality tumbler. For a beginner, this tumbler is adequate. However, I would not recommend it for a professional jewelry maker looking to use tumbled rocks in their projects.