Truss rod with a nut

[Wooly]

I'm trying to add a bit more relief into a neck that is pretty flat. It has a truss rod with a nut at the head stock. When I turn the nut counter clockwise, it just loosens the nut. What am I missing here? What should I be doing to add some relief? Thanks

[charles Tauber]

Adjustable truss rods are one of two functional designs. One type is "single-acting" and allows tightening of the nut of the rod to counter the strings' tension and reduce relief (bow) in the neck. Once the nut is completely loose, it has no affect.

The second design is a "two-way" or "double-acting" rod that allows actively adding or removing bow in the neck. There can be a small region in the rotation of the nut where turning of the nut neither bows nor un-bows the neck. Further turning of the nut will then either increase the bow or decrease the bow, depending upon the direction of rotation.

If your guitar has a single-acting rod, once the nut is loose, it isn't capable of influencing the neck: it can't add more relief, only reduce relief to counter the strings. In that case, string tension might eventually bow the neck some, adding relief. Failing that, compression fretting is an option, as is judicious levelling of frets or removing the frets and planing the fingerboard, then re-fretting. Some have had success with heating and pressing the neck.

If your guitar has a double-acting rod, it might just be in the "neutral" zone and further turning of the nut will again engage the rod and allow you to add relief.

[nikpearson]

This will almost certainly increase relief to some extent.

The make and model of guitar would help identity whether the instrument has a single or double action truss rod. If it’s the former then heavier gauge strings should increase relief. You may also find that leaving these on for a while increases relief even when you change back to your normal gauge

How much relief are you looking for? Quite often a guitar will play perfectly with less relief if other aspects of the set up are fine tuned. I find 0.15mm is a good compromise on most steel-string guitars.

[mirwa]

Originally Posted by Wooly

I'm trying to add a bit more relief into a neck that is pretty flat. It has a truss rod with a nut at the head stock. When I turn the nut counter clockwise, it just loosens the nut. What am I missing here? What should I be doing to add some relief? Thanks

When working with a one way truss rod you are limited when you still have backbow or insufficent relief after the nut has been relieved of all tension.

From easiest to more complicated repair options IMO

Option 1 fit heavier strings
Option 2 file some relief into the frets
Option 3 we heat the neck from the underside with a heat lamp and allow it to bend under string tension
Option 4 we heat the fretboard and clamp it to try and "slip" the fretboard a little
Option 5 remove frets plane the board refret
Option 6 install dual action truss rod

Steve

[Wooly]

Thanks for all the info.

I went from 11's to 12's and this added just a little more relief. Just enough to put it where I like it. I left the nut just snug but not tight. Maybe this will add some bow in time.