was: Fairly intricate design to etch
Hi Noel,
I wonder why your ferric nitrate turned purple when you added citric
acid? When I did that, it did not turn purple, and it did seem to
extend the life of the etching solution.
I will add that it also works with the saltwater etching
solutions----the copper precipitates out of the solution, and it
lasts much longer.
Cynthia Eid