I’m looking for a permanent green patina that will stay on a large custom exterior copper chimney cap. Right now the patina comes right off, returning to bright metal if lightly wiped with a finger. The copper was pre-cleaned with Dawn & TSP by Scotch-Brite pad, rinsed and dried, and the Green Patina solution misted on. A cap will be installed after patina process and need to know how to prevent patina wipe off during installation and get more permanence. Any suggestions? Hair spray seems to protect temporarily.
Sounds like you are doing everything correctly. We would apply the Brown to the copper first and wash it off (and highlight it with a Scotch Brite pad and wash it again). While the metal is still wet we would apply the Green Patina with a stiff bristle brush (do not wash it off) let it dry and leave it alone until tomorrow. Re-apply the Green the next day if necessary.