I’ve had the banjo for about 5 yrs and its never been playable above the 5th fret because of a bow in the neck. I was aware of this when I bought the instrument, but it had good hardware & sounded fantastic so assuming that the truss rod would allow me to set it up right, I bought it anyway. Turns out that the truss rod adjustments were having no effect at all.
After using steam to soften the glue, I managed to ease off the finger board to reveal the problem. There was no washer fitted to the truss rod for adjustment nut to tighten up against.
I added the washer and then made & fitted another filler strip before gluing back together & then filled a couple of light cracks where the neck had got damaged. Finished off with a coat of black aerosol and some heavy t-cutting.