Tightening the truss rod.

[Hawaiian]

I just got a used Kentucky KM 380 and the the neck is severely bowed.
Fortunately it has a truss rod and I tightened it (right hand turn I presume is the correct direction for a bow). It looks like it is beginning to straighten and I was wondering :

1. Should I let it rest before taking it further ?
2. How far should I go ?
Should I strive for perfectly straight or be happy if I can get it 'close enough' for fear of breaking the rod or assembly altogether ?
In other words how durable and capable of bending the wood are these things ?
Thank in advance.

[sunburst]

Truss rod effectiveness in mandolins is all over the map. Some of them work pretty well and some are just excess hardware that is of no particular use.
If the neck has been allowed to take on a severe forward bow It may be difficult to impossible to straighten it with the rod. The rod can be tightened pretty tight without doing damage, but if it is not doing it's job with firm tightening, damage is the only result to expect from excess tightening. The tighten and wait then tighten again process might help, but it's not likely to do much more than simply tightening once if that is not getting you close.
Most players don't like the neck perfectly straight, but instead prefer a little relief in the 'board. Knowing when you have the right amount of relief takes some experience and experimentation.

[Graham McDonald]

The first thing to check is if it is, in fact, the neck bowing between the heel and the nut, or is it the neck /body join which has moved and it is at that point the bend is happening. Get a short straight edge (like a 6" metal engineering ruler) that will span between the first and tenth frets down the centre of the fretboard and check the clearance at the fifth fret. If it is more than 1/32" the truss rod may help. If that section of the fretboard is flat, it is the neck join, and the truss rod won't do nuthin'

cheers

graham

[Hawaiian]

Well it looks like I got it straightened okay. Got some serious intonation issues that I'm hoping are all bridge related. And it has something metallic rattling inside the body when I play it or shake it ???? Weird.

[Hawaiian]

Sorry disregard that last sentence. It was only the nuts on the bridge that I left loose rattling. So I got the neck straightened and now just need to lower the bridge and work on the intonation. It looks as though it was never set up properly.
Thanks for the replies and see you around the board.
Hawaiian.