Preliminary Considerations

Stone Sizes

In order for the tumbling action to work, you must place stones of various sizes in the revolving barrel. They need to range from not more than half the diameter of your barrel to about 1/10th the size of the largest stone. You cannot simply put a few large pieces in the tumbling barrel and expect them to come out nice.

Simply gathering stones in an assortment of sizes isn’t too challenging. If all the sizes you need aren’t readily available, simply use a hammer to create them. However, if you intend to work with stones the size of melons, you’d better be prepared to gather a lot of filler!

Tumbler Size

Knowing what you want to polish and the size range of the stones you need will help you determine what size tumbler to buy. The largest stone you can finish will be about half the diameter of the barrel. Therefore, your least expensive models with a barrel four inches in diameter can only finish two-inch diameter stones. Moving up to a machine twice that size will cost twice as much and require twice the abrasives and filler. For the serious lapidary, this is a…