Join Date: Apr 2005
I agree that a few more rounds of etching are likely to reveal some laminations. No twistcore, I’d guess though.
While phosphoric acid may be safer for a permanent etch (BTW, what concentration is given on your bottle, Dave?), ferric chloride yields a strong contrast for an exploratory etch of a not fully polished surface ; be careful though since it tends to promote ongoing corrosion: I’d just etch a window along the middle of the blade first.
The final approach will depend on the outcome.