Sorry to dig up such an old thread- but this is the somewhat difinitive instruction on the bluing-bleach etch method.
But I have a question... First off, I am wanting a look somewhat like Andy's "spalted steel", and most all of the tutorials I have found show the knife in a vertical(ish) orientation, I am wondering about a larger bath- like a pyrex 9x13" pan. Does anyone have experience with this? The possibility of the down side of the blade having a different look than the up side- if it does, I am thinking I might just mask with petroleum jelly on the down side, process once, mask the etched side a d repeat with the former down side. Clear as mud?
Any input or ideas or picturs of your experience would be greatly appreciated!