>I was trying to find some FeCl for etching brass,
Mike, the peroxide/hydrochloric works well enough for brass too, or at
least well enough that I haven't bothered trying the FeCl I have.
Agitation/etchant flow is a big factor as was noted on the page linked in
this thread, but it's not all that difficult to manage even without
setting up a bubbler. I've also found that variations in the mix, if
you're doing simple tray-rocking, can produce different surface finishes
on areas that aren't etched through - finding that I could get a shiny
surface on the parts I was working on was nice (seems to me that was with
etchant that had lost effectiveness and didn't have much copper in it,
with just enough peroxide to liven it up)
-Gary