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FINISHES

BY NANA SHOWALTER

                In early October, 1991, I took a class entitled ‘Interpretive Sculpture’ taught by Ed Gray, metalsmith and jeweler, of Fennville, MI.  The class was held at the John C. Campbell Folk School, Brasstown, NC.  My tuition was subsidized by an UMBA scholarship and in keeping with the terms of the scholarship, this is the first of two articles to pass along some of the processes and techniques learned there.

                 The weekend class involved techniques for evoking creative inspiration and the subsequent designing of a sculpture.  The processes used to construct the sculpture were mixed media including metals (copper, brass, and silver).  I will discuss the methods of inspiration first and follow with specific techniques for copper work, namely a variety of colorful patinas and some silver brazing methods.

                Ed Gray is a Native American.  For most of my life the art making process has been inspired by the artifacts and philosophies of the ancient cultures of North America.  To  find myself in a class with just three other students in a fully equipped metal working studio, tucked away in the Smoky Mountains during peak fall color, felt like the winds had carried me to exactly where I belonged for those three days.  (Actually, I enjoyed it so much that I stayed for another full week of class.)

                The creative process for me has always been very subjective.  I do not believe there is a formula for achieving an inspired moment or thought that can be interpreted into a work of art.  Individually we are moved by varying situations that lead to different creative ideas.  The instructor of the class saw the creative process much the same way as I, so my reservations were eliminated.

                At the beginning of class we watched a video tape called ‘Beyond Tradition’.  It gave an overall survey of different Native American cultures and their hand-crafted wares, both functional and religious.  It dealt with basic philosophies of integration of all beings and the sanctity of the earth.  The intent was to embrace many generations, cultural differences and Native American oral teachings.  We were then given three separate paragraphs on a subject that we were to interpret into a sculpture.  Throughout this inspiration time we listened to Native American flute music.  We began the first hands on work by taking a slice of wood and some paint and painting the image of our first ideas.  From this sketch we would interpret the ideas into a sculptural form using metal working techniques.

                For the sake of this article, the actual object is almost inconsequential.  For me, it was more important to try every technique demonstrated and come home with intricate notes and samples of the results than to produce a sculpture.  These new techniques would be used in many sculptures to come.  I have found that forged ironwork can be accented by the addition of colorful copper elements.

                The techniques I am about to describe are mostly done on relatively small pieces of 16 oz. Copper, which is a good way to start until you get the feel of the materials.  When the techniques are understood, you can move onto larger items, larger torch tips, and greater amounts of chemicals.   Most of the supplies are readily available, with a minor amount of hunting.  I will make a complete list of materials and some suppliers elsewhere.  Between a welding supply shop and a nearby lapidary store I found just about everything required for a reasonable fee.  The instructor for the class let us know that some patinas we were to learn are commonly known and others he achieved through the years of experimentation.  He basically started with a disclaimer that was no chemist and didn’t recommend fooling around with chemicals unless we knew what we were doing.  He said that he wasn’t always sure why certain techniques worked, but that they did and he tested then over time.

                One of the most important aspects of applying hot patinas is the consideration of safety.  When heat is applied to metal treated with liquefied chemicals a VERY TOXIC steam is released.  In order to use the information I learned in this class at home, I installed a simple ventilation system in my studio.  It consists of a squirrel cage blower and some 6” stove pipe connected to a funnel-shaped hood.  The fan vents out a window and has a damper to keep cold air out.  When I am ready to work I simply turn on the fan and all the gasses are drawn out of the room.  This is VERY IMPORTANT.  I do not recommend that you try any of these techniques until you have arranged for some type of safety situation in regard to the fumes.  Remember, even if you wear a respirator during he process, the fumes will still get into your eyes, or your dog will breath them, and they will remain in the room until you have totally ventilated the area.

                Generally speaking, the copper to be colored needs to be completely clean and free of grease and dirt.  One of the most efficient ways to do this is to soak it in a hot pickle.  We used Sparex No. 2.  this is an acid that brings the copper to a bright finish in relatively short amount of time, especially when a pickle is heated.  One way to do this is to mix up an amount in a crock pot and set the temperature on medium.  Crock pots are ceramic and therefore will not corrode or contaminate the acid.  You’ll need copper or wooden tongs to retrieve  the work from the acid.  Pickling acids are sold with complete safety instructions so you can read about proper use for the particular brand you select.  Remember, a hot pickle lets off acid steam so don’t breath it. 

                It would be most convenient to have a sink with running hot and cold water to complete these processes, however, it is not required.  I have cold running water in my studio, and have set up a large pan on the wood stove to heat water.  Then I set up three plastic dish pans, one for a clear rinse, one with hot soapy water and the third for a final clear rinse.  I always have an emergency pan of clear water for accidental acid splashes on skin.

                If you are working with brand new copper, you may only need to rub it free of grease and oils with fine steel wool before applying the chemicals.  If your copper has any other contaminants on it, soak it in hot pickle for about five minutes then rinse thoroughly with water followed by soap and water.  Remember that pickling acid is just that, and will burn exposed skin and eat through your clothes.  Rubber gloves and eye protection should be considered. 

                Now that you have a perfectly clean piece of copper, the next step is to set up a place to heat it evenly.  The most effective method is to get a few pounds of pea sized pumice and spread it out evenly in a pie pan.  A heavy aluminum pan works as long as you don’t aim your torch directly at it.  The pan is then set on some nonflammable surface, like fire bricks or a steel table.  Heating the copper on a bed of pumice allows you to move the torch completely around the piece so that the heat actually comes up from underneath, as opposed to putting the flame directly on it and over heating one spot.

                The first color process I will describe does not require the use of a torch. 

BLACK- Black is achieved by immersing cleaned copper in liver or sulfur diluted in water.  I have seen a variety of recommended ratios of liver of sulfur to water, I use ½ tsp. to ½ gal. Water.  The chunk form of liver of sulfur has a much longer shelf life than the liquid form.  If too much liver of sulfur is added to the water, then the black will flake off the copper.  If this happens, clean the copper in Sparex and immerse in a more dilute mixture.  Heating the mixture causes the copper to blacken quicker, usually in about ten seconds.  Again, safety precautions are on the package so I won’t go into much detail.  I mix the liver of sulfur in an enameled pan on the wood stove (you could just use very hot tap water).  When it is completely dissolved immerse the copper piece using copper tongs or copper wire until the desired shade is attained.  The copper is then immersed in cold water for at least 15 seconds to fix the color then lightly rubbed in soapy water.  The ranges of color vary from lightly browned to bronze to flat black, depending on the amount of time the work is immersed in the chemical.  Liver of sulfur loses its potency after several hours of exposure to air so it either takes longer to work or lets you know that it has lost its punch.

                Black serves as a base for some blues and greens, and oddly enough for WHITE as well.  When the copper is blackened, rinsed, and dried, a variety of effects can be had by the application of Phillips Milk of Magnesia.  No kidding.  For a speckled effect, put Phillips in a spray bottle, and spray form a distance.  It can also be applied with a sponge or brush for a variety of textural effects.  If applied thickly enough, you will get pure white.  First wait for the Phillips to dry completely, at this stage it will appear grayish and dull.  Next spray it with Krylon clear fixative and it will turn a solid white.  The Krylon also turns the black from a flat finish to a high gloss.

                A wide range of colors from YELLOW to RED to deep PURPLE can be attained by using heat.  Now you get to use your pumice and torch.  Take a small amount of dry borax and slowly add water, stirring until it gets to the consistency of yogurt.  Mix an equal amount of Harris silver solder flux with the liquid borax and stir thoroughly.  Take your perfectly clean piece of copper and apply the mixture to both sides.  A 1” brush works well for this.  Make sure the entire surface on both sides is covered and place on the pumice.

                Using a small tip on the torch, slowly bring the flame to the copper in a circular motion.  As mentioned before, first heat from underneath via the pumice, not directly on the copper.  Move the torch around the piece until the flux begins to bubble, then move the flame directly over the piece while keeping it in constant motion.  Slowly heat from a distance of about 10-12”, closer if you dare.  As the copper is heated the flux mixture will bubble then turn dry white.  Next it will become clear and runny.  At this stage the patina colors will begin to take.  Heat the copper until it becomes low red and then bring the torch back just a bit to maintain that temperature for about 5-10 seconds. 

                The longer the copper is heated, the darker the finished patina color.  This is a bit of a guessing game because the color of the heated copper is not the same as the color you will ultimately achieve.  Again, the spectrum ranges from light yellow, to orange, light then dark red, purple, and if you get it too hot black speckles.  These black speckles on a dark red background are rather nice looking, like leopard skin.

                The best way to get a feel for how much heat gives what color is to take several pieces of copper and run tests.  You should be careful not to overheat the copper, however, some of the more daring results come from bringing the metal up to a bright red heat.  At this point you may be sure it will melt away any second, and it may, but if heated slowly and from a distance it will remain in a solid state.

                When finished with the torch work, the copper pieces will have a variety of colors on the surface, most of which will come off in the wash water.  The greens and blues are residual flux and borax, and after a soaking will dissolve.  Immerse the copper in hot soapy water (Palmolive green) for at least ten minutes.  At this point the residual flux should be dissolved and the copper can be gently washed with a sponge or non abrasive pad.  After rinsing and drying, the piece should be covered with a protective finish.  This can be a clear spray or a wax.  Unlike the tempered colors achieved by just applying a torch to copper, there is something in the flux and borax mixture that makes it stable.  Ed Gray uses this technique on outdoor garden fountains and finds the color to be permanent.

                The next newsletter will cover blues, greens, silver, and some silver brazing techniques.  As part of the condition of the UMBA scholarship I will demonstrate some of these techniques at an UMBA meeting sometime in the future. 

                In February the UMBA board of directors voted to increase the 1992 scholarship to $500.  I highly recommend applying for this generous amount of support.  The class I took at the Campbell Folk School has opened up many design opportunities and made a distinct difference in my work.  Application information should appear elsewhere in this or the next newletter.

                A materials list follows…

MATERIALS

Pea sized pumice gravel

Sparex Pickling Acid NO. 2

Liver of sulfur (dry compound)

Phillips Milk of Magnesia

Harris Stay-Silv  silver solder

Flux

Harris Safety Silv cadmium free

Silver solder

Krylon clear coat spray

Butcher’s Bowling Alley Wax

Cupric Nitrate

Green patina solution from Rio Grande

Palmolive green dish soap

Dry borax

                The RIO GRANDE catalogue lists small metal working tools and some patina chemicals.  It also has a variety of books on processes, and is a great wish book!  For more information, visit your Public

Library and look under Copper work, jewelry design, and patinas.  Centaur Forge also sells books on this subject.

RIO GRANDE

6901 Washington N E

Albuquerque, NM 87109

1-800-545-6566