Actually the B.C. patinas are Selinic Acid based.
To my recollection, the bluing products are selenic acid, the Plum
Brown formulation used to contain a mercury compound, mercuric
chloride, I believe, I'm not sure it's still even made.
I find that I have to get the metal rather hot so the sprayed
FN steams off very fast. Even apply a bit of heat to the "dry"
metal will often bring the FC coloration up.
If you get the metal too hot, the solution will "bounce" off and do
nothing. It takes experimentation, and a lot depends on the type of
surface you have. The trick I found was to get the right
concentration so that the FC didn't simply etch itself right back off
We are now using Liberon Wax, as of all the paste waxes we
have tried (MANY) Liberon is the only one that does not easily give
a white "residue" in crevasse like the other waxes do.
Do you have a source for this Liberon Wax? I'm not familiar with
it. By the way, if folks want to see the results of a ferric
chloride coloration, next time you're in a Border's bookstore, go to
the crafts section, look for a largish coffee table book called "The
Contemporary Blacksmith" by Dona Meilach, and look in the index for
my name. I have a piece in that book that was done with ferric
chloride (and other secret ingredients).
David L. Huffman