NOTE (January 4, 2013): Someone recently asked me (thanks, Patty!) if it was in fact brass not bronze in the following blog post, and I think they are quite right. Although it was a year ago, I'm almost certain we were experimenting on copper and brass, not copper and bronze. So every time you see the word "bronze" in the following blog post, please replace it with "brass". Thanks!
Back in February, I posted a link to place that sells chemicals and shows recipes on their website for making up different patina recipes.
A lampworker who lives somewhat near to me contacted me because she had also noticed that website and it sparked interest for her too. She asked if I’d be interested in going in on some chemicals with her and then getting together to test them out. And that’s how I met Elizabeth Dauch… super nice person, great artist, and beautiful lady with an awesome family.
Yesterday we had our patina party and here are the results.
Elizabeth is super organized and already had several recipes written out on index cards.
She had also made a batch of bronze wire spirals that we would be using as testers.
I came with a baggie of pre-cut copper shapes… and a few brass discs. This way we had three metals to try for each method.
Here’s a photo of our initial work space and set-up. The metal was cleaned two ways. Some pieces were given an alcohol bath (shown) and some pieces were cleaned with Penny Brite. We used thread to suspend the pieces that had a hole and chopsticks to hold the pieces that were just discs (note to self: make holes in all the metal shapes first or create a “dunking basket”). We also had some steel wool on-hand to occasionally rub on the metal after patinizing. We used basic sharpie markers to add resist to the copper and brass.
We started with some liver of sulfur recipes that used household ingredients.
BTW, I’m showing you our methods and results (as opposed to trying to teach you about chemical reaction patinas), but I will also add some basic warnings. As Elizabeth wisely reminded me, never add water to an acid… always add the acid to the water. And when appropriate, we were using at any given time: protective gloves, goggles, respirators, and aprons.
Let me go over a brief explanation of LOS (liver of sulfur) for anyone not yet familiar with this handy product.
LOS comes in three forms that I know of (and have used).
Premixed liquid (the form most readily available at your local bead store). The only disadvantage I find to this is that it’s easy to use it up fast.
Dry chunks (aka LOS solid) that you mix with water.
Premixed LOS in gel form. A little goes a long way and I’ve had mine for years and it’s still doing fine.
These photos are examples of what I have on-hand, but there are many companies that produce the product and I’ve not found any difference in manufacturers’ quality.
1 cup of boiled, distilled water
1 tablespoon of distilled, white vinegar
1 measure of liver of sulfur
A “measure” of liver of sulfur is this: both Elizabeth and I use the gel form of liver of sulfur. When we added LOS to our recipes yesterday, we did so by dipping the butt end of a fat paint brush into the jar of LOS gel about half an inch. Whatever stuck to the end of the paint brush is what got mixed into our recipe.
Here’s what the set-up for test 1 looked like. The mixture was opaque (which really made me wish I’d thought ahead to make a “dunking basket” because neither one of us could hold onto the little brass disks with the chopsticks (shown).
We were, however, using coated gloves so it was okay to dig into the stuff when we had to fish a piece out.
In this photo, you can see the “LOS” dipping paint brush.
The bowl of mixture was kept on a heating pad (we discussed that one could also use a coffee pot maker or a mug warmer).
When dipping pieces, we immersed them for 1-3 seconds and lifted them out to see the reaction, sometimes placing them into a stream of running tap water between dunks. You can always continue dipping to increase the intensity of the patina, but if your reaction goes faster than anticipated, your piece can darker beyond your wishes and/or attain a coating of dark patina that flakes when rubbed (you don’t want that).
The station was set up with a bowl of plain water mixed with baking soda as the final dunking place for the pieces. This alkaline bath arrests the patination process. It’s possible for a piece to continue to darken after being removed from the solution if the patination process isn’t completely halted. So sometimes just rinsing in water isn’t enough.
We numbered our paper towels so that the results and the tests could be kept in order.
Here are the results of Test 1 (we hadn’t yet started using the brass disk then). Kind of a warm patina with reddish undertones.
Then we dipped a q-tip into alcohol (plain household rubbing alcohol) and removed the sharpie marker resist. This ended up being the only piece where the resist left a dark effect.
BTW, I suggest not waiting until the next day to remove your Sharpie resist. As you can see on some of the brass disks where I did that, the Sharpie doesn’t seem to remove fully if left too long.
And here’s a close-up of the beautiful, rich patina on the spiral. Notice how the shading varies from the outer to the inner spirals.
We didn’t started dipping the brass pieces until test #2.
(purported to create blue)
1 cup of boiling, distilled water
1 tablespoon of ammonia (could only find the lemon-scented type, so that’s what we used)
1 measure of LOS
I like when the mixture is translucent. It was easier to find the brass disks that kept escaping the chop sticks.
We were both thrilled by the results of this experiment. The colors ranged from vibrant reds and yellows to warm browns and cool shades of purple.
Here’s a close-up of the part of the bronze spiral so you can see the rainbow of colors we got.
Here’s the backside of the copper piece.
And when I compare the photo of the back of this piece of copper with the final photo (at the end of the blog), I come to the conclusion that what I’ve heard about Renaissance Wax removing the vibrant patina colors may indeed be true.
We determined that the brass disks must have a coating of some sort on one of their sides because we consistently got one side that took to the patina and one side that seemed resistant (so after experiment 2, I started adding sharpie resist to both sides of the brass disks).
1 cup of hot coffee
1 measure of LOS
We both loved the super rich brown tones achieve by test 3. The pieces had that very aged vintage bronze tone (except for the resistant side of the bronze disk).
Then we moved from the kitchen to the garage for the tests that involved the chemical we had purchased.
(purported to create apple greens)
A straight LOS/water combination to get a medium brown tone on the pieces.
Then the pieces were heated to 200 degrees F in a klin.
Then they were dunked into a mixture of:
236 ml hot, distilled water
1 tablespoon cupric nitrate
We were supposed to be creating a light green patina, but we didn’t see much effect.
So we decided to torch heat (Blazer micro-torch) the copper piece and re-dunk it in the test solution. Here’s the back of the copper piece.
One interesting effect of the torch was that it removed most of the Sharpie resist and concentrated one dot of it on each place where it had been (which couldn’t be removed with alcohol).
We continued to try heating the copper piece and redunking without much success of a green patina.
The bronze spiral didn’t seem to be having any effect from the solution so we left it in for a total of 8 minutes. When we removed it, there was a coating on it which easily flaked off when rubbed gently.
But we did notice two small spots on the bronze spiral that looked like the green/blue of weathered copper and bronze, so surmised that since our directions came with not “saturation” times, some of these recipes could very well be more suited to overnight saturation rather than a few minutes of dunking.
There was no effect to the bronze disk in this solution other than to remove the original LOS patina we’d put on it.
So then we moved to phase 2 of test 4…
A second bowl with:
236 ml of hot, distilled water
1 teaspoon of Ferric Nitrate
The results were not drastic, but were interesting enough to try with variations in the future.
(purported to create blue)
236 ml hot, distilled water
50 grams Ammonium Chloride
4 grams LOS
Since we weren’t using LOS in solid form, we just guessed at the amount of LOS needed (in retrospect, I’m thinking we may have underestimated… when I consider how much 4 grams of solid LOS would be).
Again, the black coating on the bronze piece flaked off when rubbed gently, but underneath the flakes was an amazing vintage bronze tone that we both fell immediately in love with.
Elizabeth took photos of all the finished pieces after we’d added a coating of Renaissance Wax to them, so I will update this blog with those photos as soon as possible.
The brass disk was not dunked into the solution. Instead, we brushed some of the solution onto the disk and let it sit. The other two pieces (the copper and bronze) were dunked.
As you can see by this photo, the piece where we brushed the solution on and left it does seem to have created a nice patina. We just needed to be patient.
We came up with the same thoughts as on the first part of test 4, that if the solution were left on the pieces for a much longer period of time they would probably gain a patina. So then we painted some of the solution on the copper and bronze pieces too.
Keep in mind that portions of this patina have a texture.
A bed of salt and ammonia
A closed container
A way to suspend your piece(s) in the fumes of the mixture
We used regular rock salt (like for making ice cream) mixed with the same lemon-scented ammonia from before. Equal-ish parts.
We then taped a piece of thread across the top opening, placed our pieces on the thread, and closed the lid.
Supposedly, you get a nice patina after 15 minutes, but we checked the results and decided they were pretty faint so we went back to lunch (thanks, Elizabeth!) and left the fumes to do more work.
After 45 minutes, the results were more noticeable. Here we’ve lifted the copper piece up so you can see the patina on the back of it. Notice the wild shades of green and yellow on the bronze spiral holding the copper piece.
Anyway, I’ve probably left some things out, but I’ll update this page as I think of things… or as Elizabeth reminds me of them. :-)
I’d like to thank Elizabeth for opening her home to me for this fun day of experimenting.
We both found it interesting that some of the patinas we had the most success with were the “kitchen ingredients” solutions, rather than the specially purchased chemicals. We also discussed that within each recipe there is still room for experimenting by altering things such as dunking time, temperature of liquids, the application of torch, etc.
We will be experimenting more in the future, both together and separately and look forward to sharing the outcomes.
I'd like to update this blog posting by adding the link to Elizabeth's write-up of our experiments: http://threadinglightly.blogspot.com/2012/03/patina-party.html