We did etching on copper and aluminum, using a car battery charger and a plastic shoebox filled with saltwater. It worked really great, and really fast. We masked it with the iron-on/laser print method, and the mask was really sharp and detailed.
It might take some experimenting to know how long to leave it in the electric bath. We etched right through the aluminum can the first time. oops.
take a look through my pics I have a piece of brass etched "pick guard 11811" using ferric chloride. (radio shack)
its a chemical so take the proper care and i suggest diluting it. VENTILATE!
You can use various resists: lacquer, nail polish, sharpie marker and in the case of "11811" vinyl lettering. I have a 24 in. vinyl plotter, comes in handy... I've never done the battery charger and salt water trick.
( I think I have a bad memory and short term memory loss memory loss from an experience with electricity and water and electricity in the same endeavor...)
Diane mentioned (Hi Di) that she etched right thru the can, "etch piericing" is a very cool way to cut thru a piece of metal and can be controlled like a saw with practice. vigilance is recommended. good luck!
I used the so called toner-transfer method to etch an ornament into brass. First I printed the pic on a laserprinter, then the toner was ironed onto the brass. I put the plate into water and took of the paper fibre while the toner pegged on the brass. The I put it into a bath of natrium-persulphate for 30 minutes. This bath is heated to approx 40-50° Celsius; air bubbles maintain a good fluctuation of the liquid. http://handmademusic.ning.com/photo/headstock-brass-cover-plate?con...
The brass had a thickness of 0.3mm, in some areas it was etched through, http://handmademusic.ning.com/photo/headstock-brass-cover-plate/nex...
I went low tech on this one. I cleaned the brass sheet well with denatured alcohol, then applied rub on letters and drew the border with sharpies. I then applied circuit board etchant with a foam brush then rinsed many times to etch the plate. I touched up the artwork between cycles as needed. It was a slow process, and I could have etched deeper, but the overall effect was neat.
Jason, thanks for calling my attention to this idea! I've seen a similar process used to create printed circuit boards, but that always seemed like a lot more expense & effort than simply using perfboard. Anyway, after reading your post I decided that I wanted to try this. The "RootKill" brand of copper-sulfate was over $20 at the store, but I was able to find a 1 pound bag on ebay for $10 shipped. I already had an old 200w desktop computer power supply sitting around, so I'm using that as my power source. I've spent the last couple days experimenting. The etching is really fast using this method. One thing that I found essential is the OHP permanent marker. It's great for touching up any little spots where the toner comes off, but i found that going over all the toner with the marker helped the toner stay on longer during the etching process, allowing a deeper bite before the toner inevitably starts to come off. This is the best I've been able to do so far..