Monday, September 24, 2007

Copper, Now with Ammonia!

After finally getting a hold of a bottle of Ammonia, I was able to try out the original, unaltered patina recipe. Here’s the recipe (courtesy the Urban Farmer Store) and my results:

2 cups White Vinegar
1 ½ cups Ammonia
½ cup kosher or sea salt (according to the recipe, more salt = more green, less salt = less green)

By the way, the vinegar and ammonia each had a powerful smell, but once this was all mixed together, the smell was not bad at all.

Day One: Cleaned and scoured out the copper post-topper, then filled with clear liquid.



That evening, the solution had turned a wonderful blue hue.



About 4 days later, here are the results, with still a little liquid at the bottom. As I put less salt into this batch, there are a lot less crystals.



Eight days after making the batch and it is dry. Note how the color at the bottom is more blue than the rest. This may be due to it getting rained on outside last night (I left it outside to dry out a little faster and forgot to bring it in).



I did a little research on how to make vinegar and ammonia from scratch.

Vinegar won’t be hard… I have a friend who has made a few bottles accidentally when home brewing. Ammonia will be a bit harder. Today it’s made using the Haber Process, which uses high pressure (200 atmospheres) and high temperatures (450 C) and an iron catalyst to get Nitrogen & Hydrogen to react and form Ammonia. There are some other historical ways to produce it, and I may try those (playing vegetable and animal waste products… joy.). My other substitute (see last entry) seemed to do a pretty good job, but it began to smell pretty bad towards the end of the experiment.

So, I’m going to do a matrix test of the four ingredients (salt, vinegar, ammonia, and ammonia substitute) to see if I can eliminate any one of them. Here’s my two test sheets:

1 comment:

  1. I really liked the aquamarine / patina coloring on this one, Troy. This is a really cool thing you're into - the more I read, the more interesting it becomes.

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