Maybe Japan Black instead as that allows some of the timber underneath to be seen?
Black inks & dyes can be tricky to use and quite often come out some crappy shade of brown. I have always considered doing a weathered black look and from past experiments good quality fountain pen ink seems to be the best bet, applied full strength, allowed to dry for at least 24 hours, and then wipe as much off with a 'just damp' cloth to soak back up as much as you can. This leaves more of the full strength colour in the grain and removes most of what tends to sit on the surface.
Rarely had a stain idea go to plan as each bit of timber reacts differently and you end up just having to make the most out of how things progress.