Think & Tinker, Ltd.
P.O. Box 1606, Palmer Lake, CO 80133
Tel: (719) 488-9640, Fax: (866) 453-8473
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On-site Assembly of the GC18 Air Agitated Etching Cell
(page 5)

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  1. Locate the board clamp. Rinse thoroughly under warm tap water. Do not use a detergent or commercial cleaner that might leave a coating or film.
  2. Drop the clamp into the slot provided in the tank cover.
  3. Your etching cell should now look a lot like the tank pictured on the left.
  4. Drop the cell into a frame or into a cut-out table top. Make sure that there is enough space between the drain coupling and the floor so that all of the electrolyte can be drained into 5 gallon (20 liter) carboys if it becomes necessary to service or clean the cell.
  1. Install the rest of the drain hardware, and orient the PVC valve for easy access.
  2. Let the cell set for at least 2 hours before proceeding. This will give the PVC cement used on the drain hardware time to harden. Take this time to hook up the heater, temperature controller and float switch.
  3. After the cement is dry, the cell is just about ready to use, but be patient and read on for instructions on leaching and preparing the tank to etch your first board.

  4. Fill the tank with hot tap water and inspect all of the fittings for leaks. While hot water is not as invasive as a sulfuric acid based etchant, it is much easier to clean up and useful for finding large leaks.
  5. If any leaks are found after 30 minutes or so, empty the tank and repair the breach. Repeat the hot water test until all leaks are found and eliminated.
  6. Drain the tank.
  7. Put on an acid-proof smock, elbow length gloves and safety glasses (or a full coverage face shield if available).
  8. Refill the tank with a hot 10% to 12% solution of sulfuric acid (H2SO4). The easiest way to mix this solution is to add HOT deionized (or distilled) water to the tank until it is about 2/3 full. Top off the remaining volume (just up to the bottom surface of the anode hanger plate) with commercial grade automotive battery acid (35% H2SO4). The acid solution will leach out all of the impurities and greases that may still remain attached to the tank and sparger pipes. Inspect all of the fittings for leaks. If a small leak is found, leave it alone for now, but note its location for repair after the tank is drained and rinsed. If you find a rather large leak, you will have to empty the tank immediately, rinse it and effect repairs before continuing.
  9. Adjust the heater to 135°F and allow the tank to come up to temperature. The green LED on the temperature controller will cycle on and off when the tank is up to temperature.
  10. The heated acid solution should be left in the tank for a minimum of 4 hours (overnight is better), while heating continuously, to insure that the all potential contaminants are leached out.
  11. After the leaching is complete, turn off the heater and drain the tank completely, being sure to allow all of the leachant to drain out of the sparger pipes.
  12. Rinse thoroughly with hot deionized water.
  13. Fill the tank with fresh etchant to a point about 1/2" below the bottom surface of the tank cover.

  1. Always cover the tank with the tank lid after use. This will keep airborne particles from contaminating the etchant.
  2. Never add anything to the bath without having run a chemical analysis.
  3. Go to the Etching Copper Substrates section of the Processing guide.

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Established 1990

On the web since 1994

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