I am restoring a 1912 commercial roadster. The windshield that came with the car is the type that folds aft and locks into place when fully raised. I am not sure what manufacturer made it. It is also black, but appears brass underneath the seemingly anodized coating. Beneath the black coating is a reddish colored coating over the brass. What is it? What is the coating? How to restore the proper finish. I suspect it is brass and aged with a resistant patina. What is the best treatment for this condition? Am i about to destroy a finish unknowingly?
A few photos would help. Keep them under 194 kb.
To determine if it is brass, hold a magnet to it.
If brass is dipped or soaked in a solution of hydrochloric acid (muriatic acid) and water to remove the tarnish, it will take on an orange or copper hue. My experience is that the longer it is in the solution, the more orange it will be. Some folks use "The Works" toilet bowl cleaner to do this - it is a mixture of hydrochloric acid and water.
Brass will also get an orange hue if you use phosphoric acid (such as Naval Jelly rust remover) to remove tarnish.
Try a magnet, if it sticks it's steel if not is brass. You mentioned 12-13, 12's were brass and 13's were steel and had a hinge running across the center of the frame. The 1912's had exterior hinges on each side.
Thanks for the input. I looked at a forum article of 2009 and it looks like a Metzger Automatic windshield. Brass. Thanks for the tips on cleaning. Will try a spot before immersing the entire frame. Will post photos of the before and after in due course
In my post, I'm not recommending that you immerse the windshield in muriatic acid. You had mentioned that your windshield has a reddish colored coating. The reason I mentioned muriatic acid was perhaps that someone had used it in the past on your windshield resulting in the reddish color.
Thanks for the note. In actuality, I would not venture immersion - it might enter voids and give problems later. Will continue search on the best way to go. Tx.