415 - Ferric Chloride

There are two ways to do this:

1. 1. Contact your local hazardous waste disposal company
   2. The solution must not be put down the drain because of residual copper ions left in it. To make it safe for disposal, you can add sodium carbonate (washing soda) or sodium hydroxide to neutralize it, until the pH value goes up to between 7.0 and 8.0, testing it with indicator paper. Copper will be deposited as a sludge. Allow the sludge to settle, pour off the liquid, further dilute it with water and pour it down the drain. Collect the sludge in plastic bags and dispose of it as required by your local waste authority.

Do NOT dilute ferric chloride with water. You need enough ferric chloride to completely cover your board. You may require up to 5 liters with the Economy Etching Kit and up to 7 liters with the Professional Etching Kit.

For best results, follow the procedure below. If further directions for etching or making a printed circuit board (PCB), consult the photofabrication process guide available free from your dealer.

1. 1. Fully immerse copper board in solution.
   2. Agitate until etching action is complete.

To speed up etching: Warm the ferric chloride solution between 35 to 55 °C [95 to 131 °F].

ATTENTION! Do NOT heat ferric chloride solution above 55 °C [131 °F].