Etching using chemicals Free tutorial Artsandtechniques.com Arts and Techniques School RJDS inc.
Etching using chemicals There are several ways to etch metal, this technique uses a chemical. The etching is made using a mordant called ferric chloride. SECURITY : Use this product in a well ventilated area, wear protective gloves, glasses, and an apron. Protect the surfaces you will be working on and keep away from children. This technique may be used on brass, copper, bronze and Sterling Silver.925 2
REQUIRED TOOLS AND MATERIALS Safety glasses Ferric Chloride (min 42% active ing.) Alcohol (min. 90%) Wide transparent tape Cow Brand Baking soda Sharpie marker black or ink and stamps, stamp with StazOn type ink, PnP blue paper or vinyl stencil, paint, nail polish, beeswax Styrofoam - rectangle size - 13 cm x 6.5 cm x 1.25 cm (5 x 2.5 x ½ ) that must fit in your plastic container Mask and apron Piece of metal of a minimum 24 gauge thickness Fine sandpaper Duct tape 2 plastic glasses Plastic container 15.25 cm x 15.25 cm x 7.6 cm (6 x 6 x 3 deep) Spoon or stir stick, water and toothpicks 3
PREPARATION Take your Styrofoam block and wrap the narrow side with the duct tape. Leave enough length to make a handle on top. Thoroughly sand your piece of metal and clean it well with 90% alcohol to remove any products that may have been applies to protect from rust. Avoid touching the cleaned piece with your bare hands. You may now transfer your planned design using your permanent marker, stamp or vinyl, whichever method you choose. Cover the thickness (sides) and the back of your piece in order to protect it from the mordant using the permanent marker. 4
APPLY THE RESIST You may draw your design directly on your piece of metal with your permanent marker; the coverage must be complete to ensure the sharpness of your drawing. You may also use a stamp with the StazOn metal ink. You may make your final touch ups with the permanent marker. If, for any reason, you wish to start over your drawing, you may remove the original drawing using 90% alcohol and start over. When drawing, keep in mind that the etching will take place where there is no resist; the drawing will remain intact and will be raised as opposed to the etched parts. 5
PREPARATION BEFORE THE SOAKING Prepare a strip of transparent tape (packing tape) long enough to go around the Styrofoam lengthwise and to also be able to bring back up on top. Fold over each end. Place each of your metal pieces (back to the sticky side of the tape) pressing well to eliminate any air bubbles. Cut 2 to 4 pieces of duct tape (folded over at each end). These will serve to secure the transparent tape to the Styrofoam float. Position the non-sticky side of the tape against the bottom of the Styrofoam float block bring the sides to the top of the block and secure with the pieces of duct tape. 6
SOAKING Protect your working surface with a plastic tablecloth. Wear your gloves, apron, and protective glasses. Pour 2.5 cm to 5 cm (1 to 2 ) of Ferric chloride in your container. It should be sufficient for a flat metal piece. Lay your floating Styrofoam piece in the acid solution and cover up. From time to time, move your floating Styrofoam and check the progress of the etching. Using a toothpick, you can evaluate the thickness of the etching. It is not recommended to leave in the acid for more than 1.5 hours, as the resist, like the permanent marker or the ink, will not hold. Check the piece and remove when the desired effect has been reached. You may use the acid several times and when you notice that it is not as effective, you may add citric acid to add mordant. While your piece is soaking, prepare two glasses or plastic containers one with water and baking soda (3 to 4 tablespoons) and the second with water only. 7
REMOVING FROM THE FERRIC CHLORIDE BATH Always with your gloves, apron and protective glasses on, remove the Styrofoam floater and place it on several layers of paper towel to absorb the excess solution. Remove your metal piece from the tape and soak in the water solution with baking soda for about 3 to 5 minutes to neutralize the mordant. From the baking soda solutions soak in the water and dry. Clean the left over permanent marker or other residue with 90% alcohol. 8
FINISHING Sand your piece with fine sandpaper and finish with a patina or let time do its job. PATINA (Optional) If may give your piece several different oxidized effect. You may now lightly sand your piece to reveal the etching. To protect the finish you have applied, you must complete the process with a transparent finish made for metals. 9