Edinburgh Etch - 5 litres for etching in tray

  1. Stir 1/4 litre of citric acid (250 grammes)
    in 3/4 litre of hot water.

  2. When the citric acid is dissolved, add 4
    litres of liquid ferric chloride 45-47
    Beaumé degrees.

  3. A fresh Edinburgh Etch must be
    kickstarted - let a piece of copper be
    eaten up in this mixture before use.

  4. The mixture is ready for use. Etching
    must take place in an open tray (no lid).

  5. Keep the Edinburgh Etch in the tray under
    an airtight lid or pour it back into
    the bottle after use.

    Etching in tank

  1. Fill the tank with liquid ferric chloride 45-47 Beaumé degrees and do not add citric acid when etching vertically.

  2. Switch on the aereator in the tank. The
    bubbles should sizzle only in the surface
    of the liquid.