Techniques for Tooling Copper

This beautiful piece of embossed copper art was created by Sheri and Ralph Meldrum. It was embossed then painted in oils, and is available at their Web site: http://www.sherimeldrum.com/new.html

By Frank Ross

Tooling is a process used to create designs in thin sheets of relatively soft metals such as copper. This can be done by several methods including embossing, pressing or stamping objects into the metal, transferring by overlaying and rubbing, and using various tools to dent, pierce or and hammer a design or shape.

Since the Bronze Age, copper has been a popular metal because it is soft and easily stretched and molded. Copper has similar tooling properties to gold and silver, but it’s far less expensive. The thickness most often used for this is 36-gauge, which is several times thicker and stronger than aluminum foil found in any home kitchen. Thicker copper sheeting can also be tooled, but they require greater force and are more challenging to cut. Foils are thin and conform to shaping and embossing with little force. Copper and brass foil can be readily cut to the desired size with a pair of household scissors or a utility knife.

A metal’s relative softness or stiffness is due to its temper. Tempering is a heat treatment designed to make metal more durable. Metal with a harder temper will feel thicker even though it measures the same as a softer metal. Metals with a higher temper will also be more resistant to tooling and shaping.

Copper foil is shipped in a roll while sheeting is shipped flat. Ripples or folds resulting from rough handling can be flattened by rolling the foil with a smooth rolling pin or piece of PVC pipe on a completely smooth surface such as a countertop or glass table.

To make an impression in the copper foil, place the metal on a soft surface such as a piece of foam, several thickness of soft cotton towels or a soft rubber matt. A stack of newspapers will also work, but not as well because it just doesn’t give as well when trying to create deep impressions. Metal art created in this manner are often referred to as a “copper relief.”

You can either tape a paper sketch onto the copper for a pattern, or make a rough sketch of your intended work with a soft-tip erasable marker. This will be the backside of your work. If you sketch your pattern, rub some wax paper lightly across the backside of the metal to be tooled. This will make your tools glide more smoothly when working the surface. Be sure not to get wax on the front side of your work because that will affect the patina of the copper. Following your outline, press down firmly with a blunt tool or ‘stylus’ to indent the metal and check to see if the desired embossed effect has been achieved on the reverse side. If you desire a higher relief, carefully repeat the process until the correct height is achieved. Blunt tools or styli are used to avoid accidentally poking a hole in the metal.

Your finished copper relief can be easily colored or darkened with prepared patinas. Also, by brushing paint or stain over the metal a similar effect can be obtained, but those are subject to being fragmented or chipped off with rough handling.

Another treatment consisting of buffing of the high lights with an abrasive pad gives an antique appearance.

As a piece of copper or brass is worked it will become stiffer. For high relief pieces that may be easily dented you’ll want to consider filled them with plaster from the back so they will not become damaged by handling. Another option for shallow relief pieces is to use hot glue, candle wax or paraffin will work if the finished work will not be placed in the sun or a hot environment.

Stamping, punching and piercing are very similar techniques that involve striking a tool against the metal with a mallet or hammer. Stamping leaves only an impression while punching and piercing produce a hole in the metal. You may be familiar with the most commonly available stamps for creating impress in metal; punches or stamps for numbers and letters. Without much effort, you should be able to obtain a variety of tools that create many different shapes and designs from commercial sources as well as improvised objects around your home or work area. In the early years of our nation’s history lanterns, boxes and pie safes were created with intricate stamped and pierced designs using only a screw driver, an awl or similar tool. Experimentation is always the key to innovation.

Create your own drawing and use that to emboss your copper foil or sheeting.

Rub-transfers are another excellent option for creating intriguing designs by tooling metal. Designs and textures can be rubbed from many ready available things. Any raised surface with a design, from a coin to a piece of embossed jewelry can be placed under the copper sheet and transferred by rubbing or burnishing the metal over the object of choice with a rounded tool. Be creative in your thinking. The bark of a tree, a rubber stamp in your office desk, plant leaves, natural or any object with an irregular surface has the potential to add interest to a copper relief. The amount of pressure required to obtain a successful transfer will depend on the intricate detail of the object or texture that you have chosen to transfer.

Hammering a metal surface is also known as Repousse (pronounced rep-o-zay). By repeatedly pinging the metal with a dome shaped or balled peen hammer from the reverse side you can create a high relief shape in the obverse. Hammering can be used on thinner metal but care must be taken because working the metal too much makes it hard, brittle and therefore more likely to tear. By hammering metal repeatedly, you create a pebble-like texture that can be burnished out by rubbing it forcefully with a round, hard object. A wooden ball works well. For larger pieces, thicker metal is used so it can withstand much more hammering. However, there is always a trade off. Once the thicker metal becomes brittle it must be heated to a red hot temperature and quenched in a process known as annealing.

Brass is another option for tooling. It is a more tarnish resistant alloy of copper and zinc with an attractive gold-like color. It has similar properties for tooling compared to copper, although it is a bit stiffer to work with.

The best way to learn about working with metal is to do it, and there is no time like the present for starting a project. Quick Ship Metals has all the copper and brass foil and sheeting you’ll need.

For all your copper or brass foil or sheeting needs, shop QuickShipMetals.com online or give them a toll-free call at 1-800-334-2177.

To see more of Sheri and Ralph Meldrum’s work, it’s available online at http://www.sherimeldrum.com/new.html