Finishing Tools for Metal Clay

Tumblers

These are machines that can polish jewelry in one step. They work by agitating or tumbling the metal with stainless steel polishing "shot" in a barrel or work bowl. The action of the shot hitting the metal surface thousands of times during the finishing process results in a very shiny surface.

The shot is a mix of specially shaped pieces designed to get into the nooks and crannies, but it can't get into every tight spot, so pieces are usually burnished with a brass brush before tumbling.

Rotary Tumbler: a barrel containing the shot, burnishing fluid and the jewelry pieces rotate for an hour or more. The time needed to polish metals depends on the kind of metal being tumbled. Soft metals, such as fine silver, polish in 1 to 2 hours. Harder metals, such as bronze, need at least 2 hours, and 4 or more hours is not uncommon. Rotary tumblers are fairly quiet while running.

Vibratory Tumbler: these types of tumblers work about 50% faster than rotary tumblers. They work by vibration rather than tumbling. The drawback is that they can be quite a bit louder than a rotary-style..

Magnetic Tumbler: stainless steel pins are whirred about with water and the jewelry pieces in a blender-like machine. This type of tumbler works faster than any other type. The drawback is that it's very aggressive. Fine silver becomes pitted very quickly. Use for harder metals such as silver alloy and bronze clays.

Metal Brush: use to "burnish" fired metal clay before tumbling. A fine brass brush is used for silver and gold, steel is used with bronze, brass and other metals. The fine bristles give a soft matte finish.

Flexible Shaft Tool

This consists of a motor that turns a long flexible shaft. At the end of the shaft is a handpiece that holds miniature tools and drills. The motor can be a "pendant" style that is suspended on a "motor hanger" that mounts or clamps to a table, or it can be a "bench motor". A bench motor is fixed to a base instead of hung. A foot pedal controls the motor. The advantage of a pendant-style motor is that it is off the work surface so the shaft does not interfere with tools on the bench.

Some flexible shafts work in both forward and reverse directions, making them adaptable to both left and right hand users, and for times when reverse is needed.

When we talk about flexible shaft tools, we are referring to professional grade tools designed for jewelry work. A strong motor and the ability to rotate at variable speeds is important. A 1/6 horsepower motor is the standard for professional jewelry studios worldwide. A less powerful motor limits what can be done.

Flexible Shaft Handpiece Options

There are 2 basic types of handpieces that are useful in finishing work: chuck-style and quick-change type. Some brands offer only a chuck-style and others have "swappable" parts so either type of handpiece can be changed on the fly.

Quick Change Handpiece: offers the ability to flip a lever or pull on the handpiece to release and change the tool. This style can accepts shanks that are 3/32" in diameter only. That may sound limiting, but most professional jewelry drills and accessories come standard with a 3/32" shank.

Chuck-Style Handpiece: comes with a chuck-key that is used to crank open the chuck to change the tool. The advantage of a chuck-style handpiece is that it can accept any sized tool, accessory or drill shank from 0" up to 5/32". The disadvantage is that it takes time to open and close the chuck. Since tools are frequently changed, this can add up to a lot of lost time and strain on the wrist. The key used to open the chuck is easy to misplace, so attach the key to a chain or string and dangle it within easy reach.

Foot Pedal Options

most flexible shaft machines are operated by foot pedal. Many brands offer a high-impact plastic foot pedal standard in their kits. A cast iron foot pedal, however offers additional features.

Plastic Foot Pedal: low cost and low weight. Does not typically offer the sensitivity available in a cast iron housing.

Cast Iron Foot Pedal: a small extra cost will give big returns in control and comfort. A cast iron pedal is heavy, so it stays where it's put. The pedal action is more precise and glides more smoothly, allowing for sensitive control. .

Flexible Shaft Accessories:

the wide world of polishing and finishing accessories offers many options for a variety of finishes. These are some of the most useful in a metal clay jewelry making studio.

Sanding Discs: are abrasives that can quickly remove material. Used to smooth a surface, sand out scratches, and to perfect an edge or shape.

Miniature Split Mandrels: a strip of sandpaper is inserted in the split and wrapped around the mandrel, making an effective tool for removing material, such as when smoothing the inside of a ring shank.

3M Bristle Discs: these can get into places that other tools cannot. The bristles sweep into deep crevices quickly and easily to give an all-over finish, progressing from coarse grits to finer and finer grits until the desired polish is achieved.

Satin Buffs & Mini Fiber Wheels: a beautiful satin finish can be applied to metal in a matter of seconds with a mini fiber wheel or satin buff. These are available in various "grits" for different types of finishes.

Silicone Polishing Points: these types of polishers are available in special shapes and grits. The variety of shapes are designed to get into various nooks and crannies. For instance, a barrel shape is used for the inside of a ring, and a floppy disc shape is used for a flat surface.

Mounted Brushes: available with metal bristles such as steel and brass for scratch finishes and burnishing, and in natural and synthetic bristles for polishing.

Mounted Buffs: used to buff or "shine" pieces as a final step. Muslin and felt wheels can be used with or without polishing compound.

Burnishing

Burnishing is the process of rubbing a highly polished steel tool over the metal to compact the surface. Metal clay has a "pickled" appearance after firing. When examined under magnification, the surface appears frosted. The frosted surface is metal and does not need to be removed, but burnished down. This burnishing polishes the metal surface.

Metal Brush: also called a "scratch brush". These are brushes with fine metal bristles fixed in a handle or block. Brushing lightly burnishes metal. Always use a brush with bristles that are a harder metal than what you are burnishing. Brass brushes are used for silver and gold, and steel is used with brass and bronze.

A matte finish is as easy as burnishing with a metal brush. To accent the detail and give a vintage look, next oxidize the surface and then brush lightly to reveal the level of soft matte finish desired.

Curved Burnisher: many metal clay artists are taught to use nothing more than a curved burnisher and a polishing cloth to polish metal clay. This is an effective and low cost approach, but takes more time. It is not possible to get into tight areas with a curved burnisher, so the addition of a scratch brush (a metal brush, described above) will take care of those areas.

Ball Burnishers: are hand-held tools have steel balls at the tip that are used to burnish in tight spots and small places that a brush and curved burnisher cannot reach. The pins are whirred about with water and the jewelry pieces. This type tumbler works even faster than a vibratory tumbler, but is too aggressive for soft metals like fine silver, but excellent with harder metals such as bronze.

Abrasives

These are sheets and pads that have grit adhered or embedded in the surface. An abrasive is something that removes material, unlike burnishers that only rub the material.

Sandpapers: wet/dry sandpapers in 220 and 400 grit are the most useful in a metal clay jewelry studio. These are one of the few metal clay abrasives that can be purchased from a hardware store. They are used as flat sheets or wrapped around a wooden shape to customize a sanding surface.

Sanding Pads: similar to sandpaper, but the sandpaper is glued to a foam pad that is easy and comfortable to use and offers polishing grits designed for metal.

Files

The most aggressive of all finishing tools, a file can remove a lot of material very quickly. Files are available with different "cuts", which refers to the cutting teeth.

Hand Files: a good hand file is essential to have in the studio. A good flat file in a fine (cut 4) swiss pattern will help with squaring up a flat edge very quickly.

Half Round Ring File: important tool for those making rings. Get a nice one with a cut-4 swiss pattern. Used to quickly smooth and refine the inside of a ring shank.

Needle Files: a set of fine (swiss pattern, cut-4) is used to remove scratches, refine and file metal of all kinds. Dip the grip of these files in tool coating for extra grip..

Diamond Needle Files: these are smaller than traditional needle files. Diamonds cut through all metals quickly. You'll want to dip the grip end of this type of file in a tool coating for extra grip.

Polishing

Polishing Papers: these are like paper towels with polishing grit embedded in them. They are used, from the coarsest 400 grit sheet through to the 8000 grit sheet to end up with a mirror shine.

Polishing Pads: these are small pads that give a soft shine in one stroke to fine silver and remove tarnish very efficiently.

Polishing Cloth: used as a final step to buff polished metal. Polishing cloths are sometimes charged with tarnish inhibitors so the item you polish with it stays shiny longer.