thats from the first link I posted 2nd page.. it can be used on copper, brass or alloys. you could copper plate the steel first and then apply the patina. you can make copper plate solution with ionized water, cupric sulphate and nitric acid. you can get the cupric sulphate from root killers like rootX. or you can copper plate and let it weather. it's all in the kb formulas page. you can buy 8oz of solution for $10 though
