Many professional polymer finish applicators actually Parkerize
the guns before applying their finishes (such as DuraCoat, GunKote, Norrel's Teflon/Moly, Cerakote and others).
In September 2010 we had an ATF inspection and were told we must have a Class 7 Manufacturer license because we reblue and Parkerize guns.
While still waiting we were told by another ATF agent that in addition to the re- cords we are currently required to keep, we must also keep separate records for the guns that we reblue or parkerize.
I had recently learned to parkerize
so into the tank it went.
By the way, if you opt for the commercial Redfield rings, you'll want to bead blast 'em and then Parkerize 'em to give 'em a more authentic military look.
Before this project is completed, I'll bead blast the handle and then apply a phosphate coating to Parkerize it.
Firearms with a bunch of welds on them do not parkerize