A Patina is (re)Born
Typically, people bring in a bronze or brass piece, and would like us to either refinish it to restore its luster, or at least not damage the existing patina. But what if the damage is so bad we have to refinish the item? And the customer wants to preserve the look of the piece?
Our customer approached us with exactly this problem. His mother was a member of The Daughters of the American Revolution, and upon her death in 1941 a bronze marker indicating her membership was placed on the grave. It handsomely stood in that position for seventy-one years, through rains, snow, heat waves, and even a small Midwestern earthquake or two. One day, though, it met a foe it could not best – an industrial lawn mower.
The marker was pretty beaten up. If it was just the iron stake, it wouldn’t be a big deal – that would be an easy fix. Unfortunately the emblem itself got a bad bend. Straightening it out is not difficult, but the damage and repair would badly damage the patina in those areas, leaving it with obvious signs of the damage. We gave our customer two options – we could completely refinish the marker in a satin bronze, making it shiny and new-looking, or we could try and put a new patina on it to make it look like it did before the mower incident. Since we had to clean it up and anyway, he waited until that was complete before making the final decision.
After repairing, an acid bath, and some buffing, the now unfinished bronze of the marker looked like this:
We sent our customer some photos, and he decided he wanted the patina restored. The problem is that bronze doesn’t naturally form a green patina – only pure copper does. When bronze is exposed to elements, it forms a black patina. Since the marker had a green patina originally, it must have had that patina applied when it was made. Since that was seventy-odd years ago, there is no way to find out what that patina was. Luckily, Progressive Bronze has a lot of experience and a few tricks up our sleeve. Not wanting to do something to the actual marker that we couldn’t take back, though, we ran tests a few pieces of scrap. After a few tries, we came up with a formula that provided a look we, and our customer, liked. Here’s how the marker came out:
The look isn’t complete. We did not apply a lacquer, as the patina is going to protect the underlying metal from corrosion. Because of this, the elements will continue to act on the patina for a little while, darkening the color before it settles permanently. Once it does though, it will be set for the next 70 years, or more. Or until the next careless lawnmower….