Any one here ever done much with salt water etching?
Just had a play with an old, folded aluminium box and wondering if I was expecting too much:

(big versh here if interested:
https://i.pinimg.com/originals/b2/16/f1/b216f17d6668b90995eef3ede1e860aa.jpgI just scribbled the design on with a paint marker and left it for 10 mins in a salt water bath (wired up to a 12V 2A supply). The -ve connection was bubbling away but not much seemed to be happening on the box so I left it for a bit (ie. got distracted and forgot about it for an hour...). So this was the result after a light wire wool buffing (yeah, scratched the unetched detail...)
I really like the texture of the etched metal but thought it would be deeper, you can just about catch the raised bits with your finger nail. I did slip up in that the bit of scrap I used wasn't aluminium as I first thought, I guess it was galvanised steel, wonder if that mnakes a big difference?
Anyway, I like the general feel of it so will play some more.