I began an etch on a large 12" diameter copper disk by wiping it on.
After 1 1/2 hours of little results, I taped the back and laid it
face down in shallow ferric chloride. The etchant was cold and no
movement except I would move the container around periodically.
Still almost nothing after 4 hours. I realized my etchant was too
old AFTER I got into the process. I thought, even old, given enough
time it would etch. I had had to iron on the toner resist 3 times to
get a good resist, so I didn’t want to lose the resist. I wiped it
off, pulled the tape off the back, patted it dry and will try
tonight with fresh etchant.
So, when you get into a predicament like this, how do you postpone
the process safely? Being my own fault about the used etchant not
withstanding, I still was up till 12:30 am to try and deal with
this. What can one do in this situation?
(And I learned that ferric really burns in a cut.)