Everyday someone visits this site asking if you can enamel on brass. Recently I had the pleasure of meeting Barbara Lewis whom has not only developed torch firing enamels but has produced a line of brass jewels for enameling.
Check out her store where you can pick up and the supplies and instruction you need to achieve enameling on brass! She sells Thompson’s Unleaded Enamels for this so if you already have your enamels get some of her brass jewels and get started enameling on brass!
Demo by Brenda Radford, The Gum Bichromate Process for Enamels
This process is an old photographic printing technique, and I learned it from Gretchen Goss in a workshop she gave in Oakland, California in 2009. She adapted it from photography colleagues at the Cleveland Institute of Art.
I have always been interested in creating images in enamel and this process, though it can be labour intensive, captured my imagination and so I have continued my learning and experimentation in my own studio. I have created a line of jewelery based on the famous swans we have here in Stratford (some of them come down our stream to visit my studio) and on theatre related images.
Webb, Randall & Reed, Martin Alternative Photographic Processes: A Working Guide for Image Makers
James, Christopher The Book of Alternative Photographic Processes Clifton Park, New York
Livick, Stephen Gum Printing Toronto: Stephen Livick 2001
● a well ventilated space
● a source of water, preferably warm
● a kiln
● a spray booth for applying emulsion (see photo)
● compressed air and gravity fed dual action airbrush
● enclosed exposure booth with a UV light source or photo bulbs 12-18” above surface (see photo)
● B/W negative laser printed transparencies
● photoshop or other photo editing software
● greyscale images in the size of the finished artwork
● ceramic oxides – black and dark colours
● gum arabic
● potassium dichromate (label it poison)
● ml measure with tube
● teaspoon measure
● porcelain coated steel 24 ga cut to size
● prepared copper (counter enamelled, white or light colour foundation stoned down)
● plate of glass that is not UV protected
● photography developing trays
● gram scale
● glass beaker 250 ml
● liquid thermometer with clip
● glass stirring rod
● small crock pot or hot plate
● plastic funnel
● clean hydrogen peroxide bottle or other darkened plastic bottle
● plastic film container
● panty hose
● minute/second digital timer
● gloves and mask
● use your own negatives as long as they are the same size as your finished artwork
● for all other images: using photoshop or other photo editing program, convert to greyscale, increase the contrast, resize to the size of your finished piece and finally, invert the image so it is a negative.
● print your image negatives on a laser printer as a transparency
● cut each image out, leaving some space around the image for handling
● potassium dichromate is purchased in crystalline form – you have to mix it with water, as follows:
● heat 200ml distilled water in a glass beaker to 120 degrees F on hot plate or in crock pot. Use a thermometer clipped to the side of the beaker
● add 40 grams of potassium dichromate and stir with a glass rod until dissolved
● using a funnel, pour the solution into a clearly marked darkened plastic bottle. It will store for some time.
PREPARING METAL SURFACE
● make sure surface is clean of all grease and oil using whatever you normally use: pumice, windex, heat cleaning, etc but make sure it is CLEAN
● if you want to create more than one piece at once, without touching the surface of the clean metal, use masking tape to attach all of them to a piece of cardboard
● move prepared metal to spray booth. Stand vertically against back wall
MIXING LIGHT SENSITIVE EMULSION
● into an old film container or other container that closes tightly, mix 30 grains (a scant teaspoon) of oxide, 6 ml of potassium dichromate (solution) and 6 ml gum arabic. Shake vigourously to mix and remove all lumps. You can sieve through panty hose to ensure no lumps
● pour emulsion into bowl of airbrush
● set airbrush regulator at 35-50 psi
● keep airbrush 12” away from the surface while spraying
● apply in very thin coats, starting the spray off the edge of the enamel surface, turning the metal or cardboard 1/4 turn after each coating for an even and consistent application
● move cardboard with sprayed enamels to the light booth. (Emulsion is viable up to 20 minutes)
● do not touch sprayed surface
EXPOSING THE IMAGE
● once the sprayed pieces are on the floor of the exposure booth, place the transparency negatives on the surface of the emulsion (dull side down for a film negative)
● you can place a piece of non UV coated glass over the negatives to hold them tight to the surface
● turn the light(s) on and time for 15 minutes
DEVELOPING THE IMAGE
● develop in warm water, upside down, agitating slightly
● experimentation at this stage results in many variations
● while wet the oxide is extremely fragile so touching it to anything will wipe it right off
● let dry with enamel propped vertically
● once dry, the surface is more durable and can be drawn or painted on, or rubbed off to create brighter whites
FIRING THE ENAMEL
● fire at 1450 F for about a minute
● repeated firings can eliminate the image
● varied temperature and time will create different results
The Hibiscus are chased on 18k gold. Then the surface is depleted by heating to 800 degrees and dipped in nitric acid repeated times until there is no fire scale. A layer of flux for gold is applied which is Bovano #2 then the red enamel in two layers.
Argentium 970 is currently sold in grain and only from this one dealer, G&S Metals. I just spoke with them and asked why they do not offer it in sheet and other forms. The answer was they have not had the request for offering it. I explained the interest of enamelist. And was told they have a blog on the home page top left. They would be happy to listen.So enamelist here is an opportunity. www.gsgold.com/ blog away!
I will purchase the grain and start some testing for plique a jour. I do not see a need for cloisonne as fine silver is great. But it would also be a good metal for vessels.
You can enamel on brass. Art Enameling on Metals by H.H. Cunynghame refers to enameling on brass. And Thompson’s Enamel sells it. Gilder’s Metal is how it is listed and it is copper with a bit of zinc, 95% – 5 %. It works with transparent enamels, sold for gold, silver, and copper, = medium expansion enamels, according to the their experts and you have no need for flux as it does not oxidize like copper.
Don’t fire it too often. After three or more firings, the enamel can jump off. Enamelled badges and emblems are very often made of gilding metal.
“When Joseph Trippetti returned from the Army in 1946, he studied for three years at Philadelphia College of Art and the fourth year at Sheffield College of Arts and Crafts in England, where he majored in silversmithing. He has been enameling since the 1950s. For some years he taught enameling and painting before concentrating on commissions and gallery exhibitions. The medieval tapestries still influence his designs. His cloisonné were on domed copper plaques before he turned to large steel tiles.”
Musician: 16″ x 16″, silver cloisonné wires. steel, enamel.
“Design is my main interest. My method of enameling has remained about the same these many years. Originally, my work was mainly of cloisonné on domed copper plaques. I trained as a metalsmith. For the past 15 years I have been working on white pre-coated, flanged, steel plaques, ranging in size from 6″ x 6″ to 16″ x 20″. Using the pre-coated, steel tiles I do not have to be concerned with cleaning the metal and applying base coats. I use primarily 80 mesh opaque, leaded, unwashed enamels, though I also have some 150 mesh enamels and some unleaded enamels that I use when I need those colors. To use them all in one piece, the unleaded enamel needs to be under the leaded enamel and not on top. The enamels, wet with water, are wet packed with a brush almost to the top of the wires, and then the piece is tapped to level out the enamel and fired. Before each firing, any opaque enamel on the wires is removed with a fine pointed brush. It usually takes about 8 to 10 applications of the enamel, tapping and firing for the fired enamel to reach almost the top of the wires.
The final firing, with just a thin sifting of either soft or medium flux over the whole piece, is a healthy firing with the kiln at 1500°F before inserting the plaque into the kiln. I do not wet the piece for the sifted coat. For me, the most important stage in the making of each enamel is the pen drawing of my design.”
You can read more on his techniques in the book Enameling with Professionals, by Lilyan Bachrach, and it is posted on Gonaskin’s Website at www.ganoksin.com
The pre-coated steel tiles he mentioned here, are squares of steel coated with a white opaque flux, ready to enamel. You can purchase them from Thompson”s Enamel.