Anyone who has found shiny fragments of glass, beautifully rounded pebbles, or highly polished shells on a beach, has seen how continual fine random abrasion can shape and polish even the roughest surfaces. These beach treasures have probably been in the sea for years.

Fortunately, electric tumblers, polishers, and cleaners are a thousand times quicker. Broadly, there are three types: rotary tumblers, magnetic polishers, and ultrasonic cleaners.

If this is your first interest in tumblers and polishers, the practice of cutting and polishing stones, minerals, and gems, is called lapidary.

Rotary tumblers are sometimes called lapidary tumblers, jewellery tumblers, or stone tumblers. Magnetic polishers are sometimes called vibratory polishers or oscillating polishers. Ultrasonic cleaners are sometimes called jewellery polishers or jewellery cleaners.

All the tumblers, polishers, and cleaners use water. However, as pure water is a poor cleaner, small amounts of special detergents are usually added. These detergents are called barelling compound, gallay compound, drum cleaner, or just cleaning solution.

A rotary tumbler has a motor base, and a removable revolving barrel part-filled with water, mixed stainless steel shapes or abrasive grit, and cleaner. As it turns, the metal shapes or grit particles repeatedly fall onto the material to be polished and the collective tiny scratches and impacts gradually polish and burnish the surface.

Generally, rotary tumblers are used for metal clays such as Art Clay and PMC, glass, jewellery, metals, minerals, shells, silver, and stones.

Whichever you choose, you'll need a motor base, a barrel or drum, mixed stainless steel shapes or various grades of abrasive grit, and some cleaner. These can be bought separately, but it's simpler, and costs less, to buy a complete kit. It's important to understand the differences:

The Kitiki Rotary Tumbler Kit 1 is a home kit, ideal for jewellery, gold, metal clays, and silver. It consists of a small motor base, a 700gm plastic barrel, 1000gms of mixed stainless steel shot and shapes, and 500gms of barrelling compound to keep the drum clean. The body is not long enough to hold two 510gm drums, or one 950gm drum.

The Kitiki Rotary Tumbler Kit 2 is a studio kit, ideal for Art Clay, gold, jewellery, PMC, and silver. It consists of a medium motor base, a 950gm rubber barrel, 1000gms of mixed stainless steel shot and shapes, and 500gms of barrelling compound to keep the drum clean. The body is long enough to hold two 510gm drums, or one 950gm drum.

The Kitiki Rotary Tumbler Kit 3 is a craft kit, ideal for glass, minerals, and stones. It consists of a medium motor base, a 950gm rubber barrel, 200gms of 80 grit, 200gms of 220 grit, 150gms of 400 grit, 150 gms of cerium oxide polish, and one pack of plastic pellets. The body is long enough to hold two 510gm drums, or one 950gm drum.

A magnetic polisher has a motor base, and a removable stationary drum part-filled with water, thin mixed stainless steel pins, and cleaner. A rotating magnetic field makes the pins jump randomly and the collective tiny scratches and impacts gradually polish and burnish the surface.

Generally, magnetic polishers are used for small, delicate, intricate shapes. They hold a lot less, and are more expensive than rotary tumblers, but are quieter, quicker, and simpler to fill and empty.

The Kitiki Ultrasonic Cleaner is ideal for cleaning jewellery and other objects, restoring their sparkle. It won't put a shine on a rough surface. However, they're inexpensive and very quick. It consists of a container base and a lift-out basket.

An ultrasonic cleaner has a fixed stationary chamber, part-filled with water and cleaner: no shot or grit. Electronically generated ultrasonic waves create minute bubbles which, during the low pressure part of each wave, grow until, during the high pressure part of the wave, they're compressed and implode. The energy released cleans the objects inside.

The Kitiki Ultrasonic Cleaner is ideal for cleaning jewellery and other objects, not putting a shine on a rough surface. However, they're inexpensive and very quick. It consists of a container base and a lift-out basket.

The photos show the bodies, not the shot, grits, and cleaners that make up the kits. To look at the photos, hold your mouse over the appropriate zoom button below. The photos are 480px x 360px and about 80KB so, if you're not on a fast internet connection, they'll take a short while to download.

Zoom: The Kitiki Tumbler Kit 1.

Zoom: The Kitiki Tumbler Kit 2.

Zoom: The Kitiki Tumbler Kit 3.

Zoom: The Kitiki Magnetic Polisher.

Zoom: The Kitiki Ultrasonic Cleaner.

Zoom: Ultrasonic Cleaning.

Manufacturers describe their tumbler drums as being 3.0lbs, 2.0lbs, 1.5lbs, 1.0lb, 1400gms, 900gms, 700gms, 500gms, full-size, and half-size.

However, 3.0lbs is not the weight of the drum. 2.0lbs means it holds 2.0lbs of stones, but which stones? 1400gms means it holds 1400gms of something, but what? And full-size means it uses the whole width of their tumbler.

The correct way to measure capacity is to state its volume, usually in cubic centimetres or litres. However, remembering that 1cc of pure water weighs 1gm, the weight of water is often used instead.

We measured drums from several manufacturers, and put the catalogue and the actual sizes in the following table. The highlighted drums are the ones included with the rotary tumbler kits.

Plastic drum lids need to stand in hot water to make them easier to push on. To free the lids, the whole drum needs to stand in hot water. There's a slight risk that, as you pull the lid off, you'll spill your work, shot or grit, and soapy water.

Rubber drums use a different lid mechanism: at one end there's an inner metal lid, a rubber sealing ring, a metal outer lid, and a retaining threaded-collar. They're easier to work with than plastic drums, and much quieter in use.

A silicon lubricant is used during the manufacture of rubber drums. Before use, clean the drum with a scouring pad and some washing-up liquid.

The stainless steel shot, included in some of the rotary tumbler kits, is not just round but a selection of shapes, such as pins, planetoids, and spheres, designed to deal with the range of contours on jewellery.

Although the shot is 100% stainless steel, don't leave it lying around wet: either leave it immersed in the tumbler mix of water and cleaner, or rinse it and dry it carefully.

If you need to replace the shot, don't economise and buy plain or mixed steel: unless you're meticulous about cleaning and drying them every time you use them, they will soon rust, make a mess, and ruin your work.

Grit, included in the craft rotary tumbler kit, is the generic name for the particles used to grind and polish: usually silicon carbide, a hard, sharp, angular material. In use, it fractures into smaller angular particles, so is a very effective abrasive. Grit sizes are confusing, for example: 400 grit particles are not twice the size or half the size of 200 grit particles. You'll soon learn which grit to use for different materials, shapes, and finishes.

To learn more about working with metal clays, buying and using kilns and tools, or choosing a course, look at The Art Clay Club, using the The Art Clay Club link above the menu bar.

The Art Clay Club is an information resource, not a shop, providing free on-line help, 24 7 52: you don't have to register, log on, or remember a password.

Although tumblers, polishers, and cleaners are in the Cherry Heaven on-line shop, to learn more about them, and how to use them, transfer to a dedicated resource, The Kitiki Studio, using the Kitiki link above the menu bar. Alternatively, visit the Cherry Heaven Shop in Corfe Castle village.

The Kitiki Studio is an Art Clay UK distributor, an on-line shop, and a learning centre, and provides the full Art Clay range: silver clay, slow dry, slow tarnish, paste, oil paste, overlay paste, syringe clay, paper clay, gold clay, gold paste, gold foil, cork clay, kilns, tools, books, and other materials

Aida-certified and SilverClay-certified teachers provide a comprehensive educational programme: classes, masterclasses, workshops, and Art Clay Level 1 and Level 2 teacher-certification courses.

The on-line shop includes electric kilns, rotary tumblers, magnetic polishers, ultrasonic cleaners, mini-drills, pliers, cutters, engravers, mandrels, triblets, ring guages, scribers, burnishers, abrasives, adhesives, polishes, and safety equipment.