[MakeFailRepeat] was heading to MakerCentral in Birmingham, an event to which many makers were bringing coins to swap and trade. Wanting to get in on the action, he decided to etch some coins of his very own.
Etching aluminium is a simple process, readily accessible to the average maker. [MakeFailRepeat] started with an aluminium bar, and applied sticky-backed vinyl to the surface. This was then lasercut with the coin artwork, and the pieces removed to leave a negative space design for etching. With the resist layer in place, the aluminium was placed in a bath of salt water, and attached to the positive electrode of a DC supply or battery. With the negative electrode attached to a bolt, the aluminium is left to etch, with care taken to avoid over-etching. As a final finishing step, the coins were then placed in a cobbled-together rock tumbler, using scrap 3D printer filament as media.
The coins are a little rough around the edges, but we think they’re great for a first attempt. There’s plenty of different ways to etch; toner transfer is a particularly popular method. Video after the break.