Method for Etching Gem Bronze and Other Copper Based Alloys

The long awaited 💎Gem Bronze etching tutorial!
I’ve been hard at work this past week playing around with soak times, and combinations of ferric chloride + Etching Elixir, to find which I work best! The ferric chloride bought online does not contain any extra HCl in the mixture and this is absolutely essential for getting a high-quality etch for any of your materials. Mixing your own according to the instructions below will guarantee the best results. If not done correctly do not expect your etch to shine like it does in the videos taken by myself and others who have followed the process to the T. 

Since this process uses acids to remove material to reveal the grain of the metal, a very small amount of metal will be lost during the etching process. If one is making folding knife scales or a slotted guard for a tang, it's important to cover the inside of the tang hole and the sides of the scales connected to any wood or synthetic to ensure a perfect fit up. The amount of material lost comes out to less than 1/2 a mm in most cases but, that can be enough to throw off spacing on precise projects and to share to avoid any potential unfortunate situations.  

Don't pour any of these mixtures down the drain, I will make a separate post detailing how to safely clean the waste chemicals with minimal effort. 

Materials needed to make 100ml of Etching Elixir:
30ml of water
30ml of 30% or higher muriatic acid (HCl)
40ml of 12% Hydrogen Peroxide.

Method:
1. Begin by adding 30ml of water and 40ml of peroxide to a jar.

2. Next slowly add 30ml of HCl. It is important to add the HCl last to avoid any acid splash back, remember, ‘always add acid.’
And you’ve got yourself 100ml of Etching Elixir!

Gem Bronze Etching Process:

1. Clean the material and get it to its final polished condition as polishing after the etch will diminish the pattern to some extent.

2. Submerge the Gem Bronze completely in Etching Elixir for 5-10 minutes. Make sure to do this outside, as this will produce small amounts of chlorine gas. 

As a note the first etch can be a little bit more aggressive and may produce some bubbles and heat, this is totally normal. If you notice this, check the Gem Bronze after ~5 minutes in the elixir instead of 10 minutes. 

If the piece is not etched to your desired finish, add it back to the elixir for another 1-5 minutes depending on how deep you’d like the etch to reach 

3. Remove the Gem Bronze from the Etching Elixir and submerge the piece completely in acidic ferric chloride.

4. Let the piece soak for a full 5 minutes in the ferric chloride. 
5. Check the depth of the etch. If the grains are not visible enough, repeat step 2 for a maximum of 5 minutes in the elixir. Then return to the ferric chloride to check the etch quality. 
5. Once you’re satisfied, remove the piece and dunk it in a baking soda/water solution to neutralize any remaining acids, and wipe down with a fine cloth after removing it from the baking soda water
6. Enjoy your etched Gem Bronze 

Another note being that small pieces without very much surface area may need slightly less time in the etching elixir. 

Materials needed to make 350ml of acidic ferric chloride:
300ml of 12M HCl
15g of fine steel wool
50ml of 12% hydrogen peroxide.

The extra acid creates an environment where the reaction of ferric chloride to cupric chloride can occur, this is how metal is removed from the piece to reveal the grain. 

Method:
1. Begin by placing the steel wool inside a glass container capable of storing the 350ml of liquid safely. Place the container outside in a well-ventilated area.
2. Add 300ml of the HCl to the container and let this react until all of steel wool has dissolved. This may take up to 24-36 hours depending on the temperature outside, colder being slower.
3. Add 10ml of the H2O2 into the solution and wait 30 seconds before adding anymore, repeat until all H2O2 is gone

All of these chemicals can be stored in glass without issue. I like to use mason or jelly jars.

One final note here being that etching is as much of an art as it is a science. As you practice the process it will become more intuitive and the quality of your etches will get better and better! 

Feel free to email or message me on instagram with any questions!