A Prize Worthy of a Viking Duel
Coming up in our Shire of Trinovantia Nova on June 18, 2015 we’ll be holding an Einvigi inspired rapier combat tournament. In researching the history and traditions of Einvigi duels, I ran across a reference to weregild (gold paid for the loss of a human life). To keep with the theme of the event, I found historical source material on the coins of the ruthless Viking raider and Norwegian King Eric Bloodaxe, c. 885 – 954 (pictured to the right). These coins will be handed out as tournament prizes to our top three duelists.
For this project I used:
-A sheet of .064 brass
-Rubber gloves and goggles
-Black Sharpie marker
-Sandpaper and metal file
-Steel wool or metal brush/wheel
To get a consistently shaped and sized coin, I traced a two dollar coin onto the brass using a black Sharpie marker. The coin blanks were then cut out using a jeweler’s saw. Cutting with these saws is a slow process that requires patience and a delicate hand. There may well be easier and faster tools for this job, but this is my tool of choice out of the tools I have at hand.
Once the coins had been cut, I gave the edges a filing to remove any sharp edges and to smooth out the shape to be a rounder form; even with a careful hand and a watchful eye, the coins weren’t as round as I wanted them with the initial cutting. I also gave the surface of the coins a quick brushing with steel wool to remove any oils and impurities from the metal manufacturing process or from subsequent handling.
When designing an image to be etched into a piece of metal it is necessary to use a resist. The resist blocks the etching fluid (in this case ferric chloride) from interacting with the metal. The simple resist that I use is a black Sharpie marker. Areas that are protected by the black marker will be the raised sections of the coin, and the bare sections will be eaten away by the ferric chloride. Looking at the historical reference piece at the top of this article, the raised sections are the letters, sword, and dots. To give the coins a raised lip around the outer edge, I also added a very fine outline along the edge on the top of the coin. To prevent the outside edge of the coin from being eroded, it also requires a coating from the marker. The coins in my project are designed to be one sided. To protect the back of the coin, it is also covered in black maker.
To etch the coins they need to be suspended, design side down, in the ferric chloride. An easy way to do this is to use packing tape. The advantage to suspending the coins in this manner is that the tape will also act as a virtually perfect resist in preventing the etching fluid from getting at the backs of the coins. Make sure to firmly rub the tape onto the backs of the coins to ensure an air-tight seal. The tape should be long enough to drape over the side of your container of ferric chloride. I also like to fold the ends of the tape over on themselves so that they don’t get stuck to the container. To keep safe, I use goggles and rubber gloves any time that I work with ferric chloride.
After four hours the coins had a sufficiently deep etch for how a coin should look. After removing the taped coins from the ferric chloride, sprinkle the coins and tape with banking soda to neutralize the etching fluid. When the bubbling from the baking soda stops, thoroughly rinse and dry the coins. The coins will need a fairly thorough cleaning with steel wool or a steel brush/wheel.
The finished and cleaned up coin (pictured to the right) looks nice and shinny. However, there’s not a lot of contrast to make the design really pop out visually. Plus, as these are meant to be old and weathered weregild coins from the era of King Eric Bloodaxe, I decided to add some antiquing to the coins.
To antique the coins, they are dipped into a solution of about a half cup of very hot water and about a teaspoon of antiquing gel. The gel is based on liver of sulfur. After letting the coins sit in the solution and flipping them with a long set of tweezers until I was happy with the antiquing, the coins were removed, sprinkled with baking soda, and then rinsed with water.
The antiquing gives the coins a darker, older, weathered appearance. However, this still doesn’t give a really good visual contrast to the designs…everything just looks older and darker. Using some very fine grit wet sanding paper I went over the design work until I had worn off the antiqued metal. The photo below shows a coin out of the antiquing solution on the left, and then the same coin after being sanded on the right. The difference in the coin colour is only due to different lighting conditions when I took the photos.
All in all, I’m happy with the result. The coins look good and have a nice weight to them when held in the hand. The design work is deeply etched and pops out visually after the antiquing and sanding. I’m debating drilling a hole near the top of each coin and adding a deer skin lace to turn it into a pendant. Possible improvements on this would include using an aquarium aerator in the etching solution under the coins for a cleaner and more even etch. Another improvement would be etching the reverse of the coins as well (if you do this, make sure to add a very strong resist to the originally etched side of the coin…nail polish can be applied and be removed very easily for this purpose).
Here’s the finished product under two different lighting conditions:
If you enjoyed this article and would like more detailed information about metal etching, check out my initial article on learning to metal etch with ferric chloride.