Not sure about the ferric chloride
, but I know that the OTHER PCB etchant, sodium persulfate, etches most metals. When I was in college, a stopper with a steel ring through the middle was used to seal a vat of the stuff and it very quickly etched enough of the metal away to start leaking.
I've done a fair amount of etching of PCBs with sodium persulfate
, both using toner transfer and using UV light exposure setups. There are a few things to keep in mind-
1. Toner transfer kinda sucks. It's hard to get fine detail- some places are going to get over etched, some under etched, and nothing is going to come out exactly like you thought. If you're thinking you're going to etch a finely detailed image on a sheet of steel, forget it- it involves too much area being transfered to.
1a. If you don't believe me, go ahead and try. I'd recommend buying the specially designed sheets that are out there on PCB making websites- not cheap, but worth it.
2. Heat and agitation make a big difference. If you can find a pump that will recirculate the etchant without any intervening metal components, that's best. Second best is an air pump and one of those aquarium air stones that is intended to form a curtain of bubbles. A small aquarium heater works just fine for the heat source- you want it warm like bath water, not McDonald's coffee.
3. I'm not *certain* it will work on stainless, but I'm betting it will.
4. If you use the ferric chloride, don't get that stuff on anything you don't want stained or etched. The sodium persulfate is more forgiving. Comparing the two page entries on Wikipedia, I think I'll be sticking to the sodium persulfate in the future, thanks.
So, all that said, have fun, and report back. I'm particularly curious about whether the ferric chloride will work on steel.