I will be starting the Benz 1886 Motorwagon shortly. The wheel spokes and a number of other copper PE parts need to be black. Rather than painting them, I am thinking of chemically blacking them. I have used brass blackening solutions on copper before, and it works okay. I looked up copper blackening online, and see there are some home-made solutions you can make, and thinking of trying it. Any idea? What are some ideas other than painting for making copper black?