truss rod adjustment

[peelar]

I have only been playing the mandolin seriously for less than a year. I have run into a problem and need some help. This may seem like a dumb question but I want to make sure I don't screw anything up. I have a Kentucky 675 and the neck seems to be bowed. The playing action is too high to be comfortable. I tried to adjust it a couple months back and it didn't seem to help much. If I am looking down the neck from the headsock which way should I turn it to make the neck straiten out? How much can you adjust the truss rod at one time without hurting it? Last time I turned it clockwise (tightened) and I'm wondering if I made a mistake. I didn't notice this problem when I first got the mandolin and I'm worried that when I got reassigned from SC to Honduras (Air Force) that the weather change may have caused the problem. However I shipped it in its case and it seemed to be in tune when I took it out. Any help would be appriecated. Thanks, Jason

[sunburst]

You turned it the right way. "Righty tighty, lefty loosy".
As long as you are using the right tool and have it securely engaged with the nut or socket or whatever you have on the end of your truss rod, you can tighten it pretty tight. Sometimes that's what you have to do to get a little short mandolin neck to straighten out. Long necks like banjos usually respond better.

Use your common sence. If you feel the wood starting to compress under the washer under the nut, it's too tight. If the neck isn't straight by the time the rod seems tight enough to start causing damage, it's not going to adjust and you need a repair.

Keep in mind that the truss rod is only meant to adjust the straightness of the neck, not the height of the action. If the neck has the amount of bow you want, anywhere from straight to slightly bowed, and the action is still too high, you need to adjust something else- like the bridge and/or the nut.

[peelar]

Thanks for the info.

[Bandersnatch Reverb]

Just for to get peelar up to speed.

Depress the G string closest to you at the first fret, and the fret that is closest to where the neck joins the body. Look at the midway point between the two frets. The doubly depressed string will be a straight line and any neck "relief" will be seen easily. It ought to be just a wee bit - about as much as your E string is thick (as a starting point at least).

If your neck has too much relief, and you want to adjust your truss rod do the following.

First back off the string tension to where the strings are fairly slack. Take off the truss rod nut, counting the turns needed to get it off the rod. Put ONE drop of oil on the truss rod - NOT TOO MUCH - and reinstall the nut the same amount of turns.

Next, tune to pitch. Check the relief again. If you have excessive relief, slack the strings just a little, tighten the nut about 1/4 turn. Repeat until you have it right, keeping in mind that some fine tuning later one may be needed - and that its not a bad idea to keep a slightly greater amount of relief in the neck than "perfect" to account for some natural variation in the neck wood due to climate changes. In other words, your neck may straighten a little with climate change, then you'd have not enough relief, which is waaay worse than having a little too much.

And when it doubt, or if force is excessive - take the instrument to someone familiar with truss rod adjustment.

[labraid]

Always better to take it to someone who knows, mostly cause they can put the neck under clamps, _then_ tighten. Tightening, tightening, tightening, puts more stress on the rod and the wood under the truss nut washer than does bending the neck to spec, _then_ tightening. Messing up the truss threads/snapping the rod can cost more than the trip out to your friendly local luthier who'll probably be kind enough to do it for free.

[London Al]

Just a small point, but no ones mentioned it so far. I was told a long time ago always slacken your strings of an instrument if its going on an aeroplane, whether its going in a pressurised hold or not . I've heard horror stories about necks on planes but I've never had any grief myself, maybe 'cos I've always done this.
Sincerely
Al