Enamel comes in a number of forms: lump, string, liquid, and powder, as well as in the optical qualities of transparent, opaque, and opalescent. The important factor in selecting an enamel is that it be made for the metal you are using. Enamel expands as it is fired and then contracts as it cools. This is called thermal expansion. The metal on which the enamel is fired must expand and contract at a slightly higher rate.
Enamels arc sold in assorted lump forms and in meshes, probably as coarse as 10 mesh and as fine as #325. Some enamelists use the fines for a painting technique. I principally use 80 mesh powder, overglazes, and the 20 mesh in transparents for some jewelry.
Enamels arc manufactured in soft, medium, and hard fusing, which refers to how they fire. The soft enamels fire the most quickly. Some enamelists refer to the soft enamels as delicate. In Thompson’s catalog, most of the 80 mesh enamels for copper, steel, silver, and gold are listed as medium fusing. Only the flux and the black have a listing as soft; the flux has an additional listing for hard.
When I first Studied enameling, I was taught to use only the 80 mesh soft flux as the base coat and then the medium fusing enamels for subsequent coats. It was not until I concentrated on painting with overglazes that I changed to using medium fusing enamel as a base coat because it did not bubble up through Subsequent layers of enamel. It is now accepted that you first apply the hard firing enamels, then medium over those, and the soft enamels for the top coats.
Some enamelists do not remove the fines from their enamels. To remove the fines from ground enamels, i.e., clean them, you either wash them or screen them through a stack of various mesh screens. To use the screens, you stack them with the coarsest mesh screen on the top and place a penny in each one to help move the enamel. You shake them until the fines arc at the bottom. Then you put each screened enamel In a separate labeled container.
To wash the enamels, use either your tap water, depending on its quality, or distilled water. I wash only the enamels I use for jewelry. Place sonic enamel in a jar, add water, stir, let it start to settle, and Pour off the milky Substance in the top of the jar. This process is repeated until the water in the jar with the enamel is clear. I seldom wash more than 1/4 cup of an enamel at a time and often List a teaspoonful.
An early instructor of mine had a wide mouth gallon bottle into which we poured the milky Substance when we washed the enamels. When enough waste was accumulated the water at the top was poured off, some fresh water added, stirred, let settle, and the milky water Poured off. When dry, this discarded enamel was added to the Counter enamel. I spread out the washed enamel on two stacked sheets of clean paper near the back of the kiln top and cover it with another sheet of white paper to keep it clean while it is drying.
Enamels arc best stored in bottles with a screw on lid, labeled with their number, manufacturer and mesh size. If the enamel has been washed, I add that to the label. The labeled bottles, arranged by color and transparent or opaque, arc kept in a closed cabinet.
Color Sample Board
Many enamelists have enamel color sample boards, one for opaques and one for transparents. The opacities only need two siftings of the colors you own. Tile transparents, often on 1/2″ x 3″ of 20 ga or 18 ga copper, show the transparent color on the bare copper, over flux, medium white, silver foil, and gold foil. You have to divide each piece into five sections: the top fifth is for the transparent on the copper. You can either coat that section with Scalex or leave it uncoated to clean after the first firing. The next section clown is 80 mesh medium flux, the third one clown is medium fusing white, and the last two sections are for the silver and gold foil. The Sections under the foil can be the flux or the white enamel. Fire the samples’ base coats and then fire a transparent enamel color over the entire piece.
For fine silver samples, I clean 112″ discs in the kiln, brush a thin coat of crackle oil the back, and sgraffito an enamel number in the dry crackle. I sift and fire a covering coat of soft flux. Then I sift and fire a covering coat of transparent enamel color. I keep the fine silver samples in a plastic box.
Binders (Enameling Gum)
Although enamel can be applied dry, there arc many times when you need to mix the enamel with a binder that is an enameling gum adhesive. Years ago, the only adhesives that enamelists were taught to use were gum tragacanth and agar. I remember buying tragacanth flakes, dissolving them in water, and then storing the Solution in the refrigerator. When Klyr Fyre came on the market, I bought a gallon of it because It had all unlimited shelf life. Other enamelists do use CMC (carbometho cellulose). Jean Jenkins gives a recipe for 5 gallons.
Enamels may be applied by sifting, wet packing, spraying or with the thumb and index finger. I do not own a sprayer, but Its use is covered in this book by other enamelists.
Making a Sifter
Except for all old fashioned, metal sided, 2″ diameter, flat screened bottom tea strainer with a wooden handle, I make my own. Other enamelist do, too. My sifters were adapted from the one Kalman Kubinyi made. I cut about a 1″ piece of plastic tubing, diameters ranging from 1/4″ to 11/2″, and shape one end of a 1/4″ wooden dowel with a half round file to fit the tubing. I place a piece of screening, larger than the tube, against a hot electric iron and then press the plastic tube’s open end against the screen. The two are held together until I see the plastic melt into the screening. I have an old iron that I keep for this purpose. (Sarah Perkins says that She uses a spatula for fusing the screen and the plastic.) The unit is removed, the screen is trimmed close to the plastic, and then the shaped end of the dowel is attached with Duco cement to the tube. The tube is placed on the workbench with the tube flat oil its side and the dowel handle upright and Supported against a set of drawers for the cement to dry overnight.
I sift over a stack of two or three sheets of white paper. I use clean white paper to see any speck in the enamel to be removed to keep my enamels clean. The sifter, half filled with an enamel, Is on the paper. Students learn to sift an even coat by covering most of the sheet of paper a number of times with Counter enamel in a 2″ sifter. I sift by tapping on the handle of the sifter with my index finger. If you hold the sifter close to tile paper, you limit the spread of the enamel as it falls from the sifter. If you want an overall fine layer, then you hold the sifter Lip higher and tap it lightly. You have learned to sift the enamel when you can do it without thinking about it.
When you need to wet the metal before sifting on the enamel, you call use all airbrush, a soft brush, or a hand spray bottle. I remember Kenneth Bates telling Students in a workshop that you aimed the sprayer at the ceiling and let the solution fall on the piece as the gentle rain from heaven. If you are using a hand spray bottle, set the nozzle to the finest spray and pump it a few times before spraying the metal. If you do not have a spray booth and you arc doing a lot of spraying with a gum solution, it is advisable to cover a section of the floor with newspapers. A floor wet with gum solution is very slippery. I do most of my spraying with water so there is no problem with a slippery cement floor.
Wet Packing (Inlaying) 80 or 100 Mesh Enamel
I pick LIP damp enamel with the tip of a #1, #2, or #3 sable liner brush and place it in the top left hand area of the design. With the side of the brush, I level the enamel to about 1 mm thick, wipe off the brush, and again with the side of the brush, draw off any, excess water. The next damp color is placed almost up to the first color and then the new color IS Pushed against the first color, evened Out, and so it continues. The size of the brush you use depends on the area an enamel color is to cover. You might need to add a very little bit of diluted enameling guru if you arc working on a sloping surface. If you are going to wet pack a piece that is larger than 4″, you Should start in a far corner and progress diagonally down to the opposite corner. That way your hand does not disturb the enamel while you arc applying it with the brush. Other enamelists use other tools for wet packing. Just try them all.
Indian Sand Painting (Thumb and Finger Application)
This techniques takes practice. The space between the first and second joint Of your Index finger is placed next to some dry 80 mesh enamel on a sheet of paper. (I have not used it with other enamel meshes.) Your thumb slides across the enamel and holds the enamel against the flat area Of your index finger. YOU start releasing the enamel by sliding Your thumb forward. You begin either at the top or the bottom of the line you are making.
Applying Liquid Form Enamel (Crackle) as Counter Base Coat
Although the name of the material has been changed, what I still have and use was called crackle. The name refers to what happens once this liquid form enamel is applied and fired over a previously fired coat of 80 mesh soft enamel. The liquid form breaks LIP or cracks in the firing because the soft enamel Underneath expands first. I Suspect it was a porcelain slip made for pottery. I still call it crackle.
When I last purchased Thompson #772 Black it came in a plastic gallon jug. I Poured the liquid Into a big basin and Cut Off the top of the jug to spoon Out the mass at the bottom of the jug. After a lot of stirring with a long cooking spoon, I was able to get the material into solution. I divided the crackle into many wide necked, glass pint jars with screw on covers, by stirring the crackle before each ladle full was poured into a jar. The jars were filled to within 1″ of the top to leave room for stirring the crackle before using it.
After my course with Doris Hall in 1955 I used the black crackle as the base coat on the back of all my plates, plaques, and shallow bowls. Originally, I held the piece over a bowl and used a small ladle to pour the crackle on the piece. Sometimes I would move the crackle with the convex side of the ladle.
I soon found that it was simpler to use a well charged, large brush for applying the crackle. I still apply the crackle with a 1″ greyhound brush. When you first receive the liquid form enamel, stir it well with a slender spoon and test a brush full. If it is too thick, gradually add a very small amount of water while stirring. Experience will tell you the right consistency. The brushing consistency is a little thicker than the one for Pouring. It used to come with a binder, so if I thinned it too much, I would set it aside to evaporate. Now if that happens, I add a little Klyr Fyre, stir it well, and it thickens. Sometimes I even have to add a little more water. For my undercoat of Counter, the crackle does not need to be an absolutely smooth coat because I will cover it with a counter enamel that is mainly opaque enamels. If I needed that smooth a coat, I probably would have bought an airbrush and Set LIP a spray booth.
The piece to be coated with crackle is placed on a jar so it is at least 2″ above the table; the side to be coated, usually the back, IS facing up. The table is covered with white paper. If I am coating only one piece and the crackle is very thick, I Just wet the brush and swish It around the top of the crackle in its jar and then brush it lightly on the cleaned metal piece. Mien the crackle is dry, I sgraffito my 7 name with a sharp chopstick in the center back of the plate. If the dried crackle powders off on your hand as you hold the piece to sift enamel on the front, it means it does not have sufficient adhesive. You can either bear with it, or remove the dried crackle and recoat the back of the piece. The crackle needs to have about a half teaspoon of Klyr-Fyre stirred into the jar. When applying the crackle with a brush, you pass the brush over the piece as though it were a feather. If you bear down on the brush as you stroke the metal, tile crackle will not cover smoothly.
When applying the crackle to a round plate, the last swipes with tile brush are around the edge of the plate. When I have finished using the crackle, I wipe around the top of the jar, add a little water and screw on the lid. My old jars have metal lids so I Put a piece of white paper over the top before I screw on the lid. The brush and the spoon get a good washing. The brush is used only for the black crackle.
The Firing Process
If my electric kiln had a rheostat, I Would set it at 1500 F and be able to forget it until I was ready to fire. I should have a rheostat; I do not know why I did not get to it. I now, turn on both infinite controls to the highest number and set a timer for 25 minutes as a reminder to check the kiln temperature. If I should forget, and I have, the inside of the kiln is almost white and the wires may be burned Out. When the temperature is at 1500 F, I turn the controls down to hold at about 1350 F. The longer the kiln is on, the more heat the bricks absorb and although the pyrometer reads the same 1500 F as it did when it first reached that temperature, it recovers faster. A heat saturated kiln is preferable.
Everytime you Open the kiln door, the temperature drops. If the kiln furniture Is cold when you Put tile Piece in the kiln, the temperature will drop even more. Although 1500 F is 1500 F, I think of a kiln that just came to temperature as a cooler kiln than one that has been at that temperature for over an hour. The inside back of tile kiln is hotter than the front part, so I often rotate a large piece for the firings. The firing is hotter closer to the wires. For larger pieces I watch that, too, and I am careful to limit their size in order to leave one inch from the wires.
The recovery time of the kiln’s temperature is important because When you place an enameled piece in the kiln, the previously fired layer of enamel cracks and mends itself. If the kiln is too cool, the cracks remain.
Sifting 80 Mesh Enamel and Firing Front and Back Base Coats
With this method, the front and the back of the enamel is fired in tile first firing. If the piece is flat or shallow, I spray water to hold the sifted enamel in place. If tile piece is a deep bowl, I spray with diluted 1:3 Klyr Fyre. Holding the underside of the piece with the dried crackle resting on my fingers, I spray lightly, sift, spray, sift, and spray, applying a damp enamel coat that covers the copper. I use the 2 60 mesh sifters for the base coats. Three of the 2″ 60 mesh stifers arc labeled to be used only for flux, white, or for counter. If I have used only water and sprayed lightly, tile Piece can be fired almost immediately. If I have used enameling gum, the piece has to be dry. If you arc in a hurry, you can set the piece, right side LIP on hot kiln furniture. If tile gum is not dry, you will see some steam rise up when you place it in the kiln. Take tile Piece Out Of the kiln, wait a few seconds, and then return it to the kiln. You can also put the set up piece in the hot kiln for a second, take it out to check for steam, and then repeat until there is no steam. I fire at 1500 F until the front base coat is smooth. When I remove the piece from the kiln, I check that the crackle on the back is shiny and smooth; if it is not, I quickly Put it back in the kiln for additional firing. If the crackle is not fired adequately it will chip off as the piece cools.
The second firing completes the counter enamel of the back. For my Counter, I mix about 113 Thompson #124A hard black 80 mesh leaded enamel with 2/3 left over mixed enamels. If one enamel color contaminates another, this mixed enamel (often called tweed) IS Put in a quart bottle and used for Inv Counter. Two good siftings with the 60 mesh screen sifter arc applied over the fired crackle, spraying with water before and after each sifting. The spraying between coats changes the color of the enamel enough to let you See where you have sifted. For the sifting on the back, I hold the plate with the center front of the piece on my fingers so none of my fingers arc protruding from under the plate. I start the sifting around the edge, moving the plate in a circular fashion and then sift around towards my signature but not over it. The center back has the signature covered with Thompson #426 leaded 80 mesh soft flux after two coats of counter arc sifted on the back.