Salt etching aluminium

Due to varied reasons (one of the main ones being a desire to create something), I wanted to try my hand at etching aluminium. I've had prior experience with it from one of the places that I used to work at and from College, but I was hoping to avoid having to use Ferric Chloride or other strong chemicals. After a bit of browsing I found that it is possible to do with salt water and a bit of electric current. That seemed like a better idea than to be using toxic chemicals (and then trying to dispose of them).

The first couple of prints failed because I was trying to print an Australian flag, but the detail was too fine. My very first print I rubbed the paper too hard and it ripped, so I scrubbed that one. The second one had many defects of missing toner or details covered by paper pulp. I used magazine paper, and that wasn't blank so some of the toner from that ended up filling in what was meant to be blank spaces.

For my third attempt at a print, I opted for large lettering, but even that was fairly dull and blurry once transferred onto the ali.

The setup … looked dodgy as anything!

Basically running a 5V DC power supply. A bit dodgy to have a stainless steel knife in a salt water bath along with the piece of aluminum being etched. I could see it not taking much fort things to shift around and get a short.

I did tape the knife to the side of the container to try and reduce the risk. Long term, I'd like to maybe get a holder 3D printed or something in order to make it safer and eliminate the chances of a short. But that's a long term thing - right now I'm trying to keep my costs down to a minimum. Current spend: $2. Not counting prior items that I already owned (such as a multimeter to check the polarity of the wires).

The result … is less than what I was hoping for.

I'm 95% certain that the reason for the failure was not enough toner on the print. I needed to use a destructive method (soaking in water) to remove the paper backing, I may need to explore other methods to get a cleaner deposit of the toner onto the aluminium. A pretty decent etch (depthwise, I mean) for only a few minutes of effort.

The end goal is nice crisp writing, and I think I am going to either need better transfer medium to get the toner onto the ali, or a better printer. I think buying toner is going to be my next step, unless I can find another option of paper I can use. Fingers crossed!