Neck problems xS

[krstko]

I bought a used bass. It was really cheap because the neck was bowed (I hope this is the correct word xD). The owner told me that he had already tighten the thuss rod. So why is the neck bent? Can the thuss rod untighten itself through time? (the bass wasn't in use for 6 years)
And what can I do?

Sorry for bad english

 

[the wako kid]

well,a neck can bend towards the fretboard(bow) or towards the back of the guitar(hump),so you should adjust it accordingly,aslso,you should wait about 45 mins to an hour between quarter turns of the truss rod(give it a quarter turn and wait.)if all is lost,you can buy a replacement neck from mighty mite,warmoth or go cheaper and go guitarfetish.

 

[Rocky McD]

If it has a bad bow and the previous owner already tried to adjust the truss rod without correcting the problem, I would be very suspicious that the truss rod was not in good condition. I would loosen the strings and check the neck bow. Then loosen the truss rod nut to see if it turns freely. If there is bow in the neck, tighten the truss rod nut slowly, 1/8th of a turn at time and check for neck improvement after each turn. If the nut binds up, stop and take the instrument to a service tech.
Rocky

 

[krstko]

Tx, I will try to repair it myself Just one question, can this rod strech or untight. I wonder how the neck bowed if the thuss rod was tightend already