Electro-Etching Workshop

1 Electro-Etching Workshop John Fetvedt Table of Contents Electro-Etching .. 5. Advantages of Electro-Etching .. 5. Safety First .. 5. Basic Electricity .. 6. Definitions .. 6. Electro-Etching 101 .. 7. Introduction .. 7. Basic Setup for Electro-Etching .. 7. Measuring Volts .. 7. Measuring Amperes .. 8. Volts vs Amps .. 8. Current Density .. 9. Cross Section of a Typical Electro-Etching .. 9. etching the Design (intaglio etch) vs etching the Background (relief etch) .. 9. Increasing the Current Density .. 10. Small Semi-Enclosed 10. Choice of Electrolytes .. 10. Resists .. 11. Computer Generated Resist Mask Options .. 11. Vinyl .. 11. Laser 13. Photosensitive Dry Film .. 16. Other Resist Options .. 19. Contact 19. 19. Fingernail Polish .. 19. Paint 19. Electrolytes .. 20. Cupric Nitrate (Cu(NO3)2) .. 20. Preparing the Cupric Nitrate 21. Disposing of the Cupric Nitrate 22. John Fetvedt June 28, 2018 2. Sodium Chloride (NaCl).

2 22. Preparing the Sodium Chloride 22. Disposing of the Sodium Chloride Solution .. 23. Copper Sulfate (CuSO4) .. 23. Preparing the Copper Sulfate Solution .. 23. Disposing of the Copper Sulfate Solution .. 23. Silver Nitrate (AgNO3) .. 23. Preparing the Silver Nitrate Solution .. 24. Disposing of the Silver Nitrate Solution .. 24. Sodium Nitrate (NaNO3).. 24. Preparing the Sodium Nitrate Solution .. 24. Disposing of the Sodium Nitrate 25. Power Source Options .. 25. Rectifiers .. 25. Other Power Supply Options .. 25. Batteries .. 26. Power Supplies .. 26. Regulating the output from Power 27. Homemade Power Supplies .. 28. Automotive Battery Chargers .. 28. Metals .. 29. 29. 29. Nickel Silver ( German Silver) .. 30. Red Brass ( Jeweler's Brass, NuGold, Jeweler's Bronze, or Merlin's Gold) .. 30. Bronze .. 30. Pewter .. 30. 30. Steel .. 30. Preparing the Package for etching .. 31. etching the Background (relief etch) vs etching the Design (intaglio etch).

3 31. Relief etching with All Resists .. 31. John Fetvedt June 28, 2018 3. Intaglio etching with Vinyl Resist .. 32. Intaglio etching with Photosensitive Dry Film or Toner Resist .. 33. Finishing the Project .. 34. 34. Copper 34. Simple Bail for Pendants .. 34. Riveting .. 35. Solid Rivets .. 36. Hollow Rivets .. 36. Burnishing with a Tumbler .. 37. Coating Base Metal Jewelry .. 38. Q-Tip etching .. 39. etching from Photographs .. 40. Colorscape App .. 40. Background Removal using Microsoft Powerpoint .. 41. Vacuum Filtering the Electrolyte .. 42. Electro-Etching Studio Equipment .. 43. MSDS for Common etching Chemicals and Resulting Products .. 45. Thank you for attending my Workshop .. 47. John Fetvedt June 28, 2018 4. Electro-Etching Electro-Etching , also called galvanic- etching , is described by Wikipedia, the free encyclopedia, as a metal etching process that involves the use of a solution of an electrolyte, an anode and a cathode.

4 The metal piece to be etched is connected to the positive pole of a source of direct electric current and is called the anode. A piece of the same metal is connected to the negative pole of the direct current source and is called the cathode. In order to reduce unwanted electro -chemical effects, the anode and the cathode should be of the same metal. Similarly the cation (the ion with a positive charge) of the electrolyte should be of the same metal as well. When the current source is turned on, the metal of the anode is dissolved and converted into the same cation as in the electrolyte and at the same time an equal amount of the cation in the electrolyte is converted into metal and deposited on the cathode. Depending on the voltage used and the concentration of the electrolyte, other, more complex electrochemical effects can take place at the anode and the cathode but the solution at the anode and deposition at the cathode are the main effects.

5 Advantages of Electro-Etching The chemicals used for Electro-Etching are not corrosive like the acids used for many other types of etching . However, most of them are not good for the environment, particularly after etching , and they need to be disposed of properly. Several of the electrolyte solutions commonly used for Electro-Etching rarely need to be disposed of. They last for years as they do not become exhausted, and they do not need to be periodically refreshed. Undercutting, or eating back under the resist, is generally far less with Electro-Etching than with acid etching . No dangerous gasses, or fumes, are created during most common Electro-Etching processes. When the same concentration of electrolyte, the same current, and the same time is used, an etching is repeatable. When silver is etched using cupric nitrate as the electrolyte, the silver removed from the anode can easily be recovered from the solution.

6 Safety First Safety glasses or face shield Always wear safety glasses, or a face shield, when working near any of the chemicals, both liquids and solids. If any of the solutions are accidently splashed into the eyes, use an eye wash station to thoroughly wash the eyes with water. Rubber gloves Always wear rubber gloves when working near any of the chemicals, both liquids and solids. If you are accidently splashed with any of the solutions, wash the area thoroughly with water. Respirator Always wear a respirator when working near any of the dry, solid chemicals. Disposal of electrolytes All solutions from the etching process may require special care when disposing of them. Read the directions for proper disposing of each chemical. Do not just pour anything down the drain. Label chemicals and solutions Store all chemicals and solutions is plastic bottles with plastic caps, clearly labeled, and in a safe place away from children.

7 John Fetvedt June 28, 2018 5. Read the Material Safety Data Sheets (MSDS) Read the MSDS for all chemicals that you will be working with, and for all the compounds that may be created during the etching process. MSDS are available on the web at , enter the chemical name in the Search for Products box on the upper right side of the screen and look for a link to the MSDS. Basic Electricity Don't panic, there will not be a test on this subject. I just want to familiarize you with some of the terms we may mention during the Workshop . Definitions A or amp (ampere) An amp is the measurement of the amount of current that is flowing. Think about an ampere as a measurement of the amount of water that is coming out of the faucet at any one time. Ah (ampere hour) An ampere hour is used to define the capacity of a battery. For example, a battery rated as 1Ah can deliver 1 ampere of current for 1 hour. Look at an ampere hour as a measurement of the total amount of water that is in the tank connected to a faucet.

8 Anode The anode is the electrode that is attached to the positive (+) side of the power supply, usually by a red wire. The anode is the metal that is to be etched. Cathode The cathode is the electrode that is attached to the negative (-) side of the power supply, usually by a black wire. The cathode is NOT the metal that is to be etched. Circuit A circuit is a complete path through which an electric current can flow. mA (milliamp) A milliamp is equal to one one-thousandth of an ampere, 1 ampere equals 1000. milliamps. Multimeter A multimeter is an instrument designed to measure electric current, voltage, and usually resistance, typically over several ranges of value. Ohm An ohm is a measurement of electrical resistance. Ohms Law Ohm's Law describes the mathematical relationship between electric current (ampere), resistance (ohms), and voltage (volts). It is stated as volts = amperes * ohms, or amperes = volts / ohms, or ohms = volts / amperes.

9 Resistance The resistance is a measurement of the difficulty encountered by the current flowing through an electrical circuit. Think of it as a nozzle on a hose that can be used to reduce the amount of water coming out of the faucet. In the Electro-Etching setup, the resistance is caused by the electrolyte. V (volt) A volt is a unit of electromotive force. Think of it as a measurement of the pressure of the water coming out of the faucet. John Fetvedt June 28, 2018 6. Electro-Etching 101. Introduction I want to point out that I generally work on one or two small, 2 to 4 inch projects of silver, copper or copper alloy at a time, and use minimum sized tanks. If you are going to work with other metals, on large projects, or in a production mode, I suggest you research the literature and experiment on a small scale until you understand the principles, hazards, and what might need to be altered, to scale up to a larger production sized setup.

10 Basic Setup for Electro-Etching Prepare the electrolyte and place it in the etching tank. Connect one end of a red wire to the positive (+) connection at the power source and the other end of the red wire to the anode, the metal piece to be etched. Connect one end of a black wire to the negative (-) connection at the power supply and the other end of the black wire to the cathode, a piece of scrap copper, and Bob's your uncle. Remember, all exposed metal that touches the electrolyte on the anode side of the etching tank will be etched. This applies to the wire, or the alligator clip used to attach the metal blank to be etched, to the positive lead from the power source. The electrolyte doesn't know what it is supposed to etch and what it is not supposed to etch. Cover all metal attached to the anode that may come in contact with the electrolyte with a resist. Measuring Volts Volts are measured using a multimeter with the selector switch set to read DC Volts.