neck bowed backwards.. won't return!

[GoChris]

I recently acquired a Yamaha BB-V MIJ bass that had spent an unknown amount of time with no strings attached and with the truss rod tightened down quite a ways. Consequently, the neck is bowed backwards. I released the truss rod nut all the way, and strung up the bass, let it sit for a week. The neck came back a considerable portion but still has a way to go before being playable, and I think that all I will get with string tension alone. I see various videos on YouTube regarding neck straightening, although only for necks banana'ed in the usual forward direction. If anyone can give me advise on how I can resurrect the Yamaha neck, I would very much appreciate it. Sorry if this topics is already addressed but I couldn't find anything. Cheers Bass Chat.

[Ou7shined]

You can make a jig that trains the neck back into shape. I built mine in an afternoon.
I'm on my phone just now so can't really find links for you but you can Google for plans or ideas.

[Mr. Foxen]

A wood block, some clamps and a table will provide an improvised jig, you don't have to push it hard. Also, heavier strings, always heavier, cures everything except bad setup.

[Billy Apple]

If you have loosened the rod off and it has moved, you may find over time it will settle back further. Try a set of heavier strings, Rotosound are very tension-y. Just goes to show what happens if you take the strings off without loosening off the truss rod.

[GoChris]

Thanks so much for the feedback. I will try the Heavy Strings for a while. If that fails then I'll make myself a jig and apply light pressure for an extended period of time.
Cheers!