Don Terrill’s Speed-Talk

I've tried lime juice, salt, vinegar, battery acid, and ammonia. Guess which chemical won out? Ammonia. I dipped the pieces into Ammonia, then stood them on end to drain on a spray can lid above the Ammonia and gently sealed the lid on the ice cream tub to let the vapors work.

I'm building a fuel rail for a three deuce Ratrod for my buddy, and Ammonia did the trick to make it petina'ed..

This ad brought to you by the Ammonia producers association, JK...

Hmm.. Sitting here reading my post, I wonder how ammonia would make a ported head appear unported...

Antiquing copper & it's alloys - as in Verde Patina (i.e. Statue of Liberty)?

Cupric nitrate and heat - apply with a brush when surface temp is above 215*F, repeat as needed to achieve desired hue - too many coats (~>2-3 dozen) can cause seperation of sacrificial coating on flexible substrates... many years of experience with a coloring torch in my younger days.
Nostalgia is dampened by memories of Antique Brown application - the Sulferated Potash required was especially stinky as the water steamed away!