Step 15: Details - Steel Buckles and Acid
For the most part I just followed the process outlined in the link above. I started out by picking up a bottle of Muriatic Acid, picture 2, which is available at most hardware stores. You shouldn't have too much trouble finding it as it is used to clean concrete driveways and pools. Just so you know, Muriatic acid Is hydrochloric acid so it is dangerous. I started out by pouring about an inch of the acid into the plastic container and adding the copper wire to it, any copper will do, even pennies. I put the bucket into a safe place outside with plenty of ventilation where people and animals wouldn't be able to access. It is important NOT to put on the lid completely, as the acid eating away at the copper generates gas, and if the lid is on tight the bucket could explode. I left the solution for about a day giving plenty of time for the copper to dissolve. You'll notice in picture 3 that the normally clear acid has now turned green.
You can now remove the copper wire from the acid. As a first step to help eat away the coating on the steel buckles, I put the steel straight into the acid for about 2 days. The result is what you see in picture 4. The shiny coating is completely gone and the bare steel is now exposed. Now we are ready for the magic to happen. Since I'm not a chemist, I'm not sure why this next step works as well as it does, but this is what seems to work really well for MetalGeek in the link above. Watering down the acid solution will create a much better effect, somewhere in the neighborhood of 20/1 to 100/1 of water to acid/copper solution should work well. I dipped the buckles into this new solution and let them sit overnight. MetalGeek seems to get results within about a half an hour. I left them over night as I wanted a really strong effect. You can see in picture 5 that the buckles are now nice and rusty. Perfect to match the rest of the Digger Launcher.
Again I can't stress enough how important it is to use all the proper safety gear when working with acids. The risk of losing your vision if it splashes in your eye or burning your skin just isn't worth it. Be safe.
Materials Used for This Section
Tools Used for This Section
Mask - the fumes are awful
Acid save plastic bucket