Guitar action reverting to high action after truss rod adjusting?

[Sonics]

I suspect there is more going on here than meets the eye. The OP tightened the truss rod, then after a few hours the neck reverted to its original relief. The OP also detects no change in the 'tightness' of the rotation of the nut/screw.

Two and two usually makes four, but can anyone see what these two pieces of data indicate? That's why we need the input of an 'expert'.

[chessmate99]

Originally Posted by GBS

Others have commented, and as noted, while the truss rod is primarily for addressing proper height in the mid-range of the frets, as you found, it does affect the height of the strings over the 12th fret ("action"). Just as lowering the saddle (the primary way to lower action) also may change the need for some neck bow (truss rod adjustment) to eliminate buzzing in the mid-range.
All guitars need some time to settle into new adjustments, so make them in small steps, and give it time (a day or so) to find its new equilibrium. Truss rods typically are adjusted in 1/8 turn increments. Needing more than 2-4 indicates something is not right.....Adjust yours until you get buzzing in the mid range, then back it off until it stops. This may take several days of baby steps. Then if your action is still too high, look to adjusting the saddle height.
In the case above, it may be that the rest of the guitar body readjusted itself to the new tensions, or the wood in the neck under the truss rod nut has compressed a bit, reducing the tightness of the truss rod a little. Try going a 1/4 turn more. If, after a day or two, you have the same issue, or after going a grand total of 1/2 turn and you still cannot get the midrange frets to buzz - stop and take it to a professional.

I had my guitar properly set up once, with the action reduced to a very low level. I suspected my action was too high when there was a song I kept playing, but it became harder and harder to play. Turns out when I twisted the truss rod, it was so loose and I suspected the strings were pulling the neck together.

Afterwards I twisted the truss rod clockwise till it was quite tight, and the action became so comfortable. I only do not know why the action became worst again after I left the guitar alone for a while. But one thing I did after the adjustment was to put on a capo to try out the song again - would this have an impact on the readjustment of the truss rod?

I still can't reliably tell whether the neck is straight or not. How can I tell?

[Sonics]

Originally Posted by chessmate99

I had my guitar properly set up once, with the action reduced to a very low level. I suspected my action was too high when there was a song I kept playing, but it became harder and harder to play. Turns out when I twisted the truss rod, it was so loose and I suspected the strings were pulling the neck together.

Afterwards I twisted the truss rod clockwise till it was quite tight, and the action became so comfortable. I only do not know why the action became worst again after I left the guitar alone for a while. But one thing I did after the adjustment was to put on a capo to try out the song again - would this have an impact on the readjustment of the truss rod?

I still can't reliably tell whether the neck is straight or not. How can I tell?

If your truss rod is still intact...

[chessmate99]

Originally Posted by Sonics

I suspect there is more going on here than meets the eye. The OP tightened the truss rod, then after a few hours the neck reverted to its original relief. The OP also detects no change in the 'tightness' of the rotation of the nut/screw.

Two and two usually makes four, but can anyone see what these two pieces of data indicate? That's why we need the input of an 'expert'.

Yes you are right. The action was so darn comfortable after the adjustment, and I could suddenly play all my runs without a hitch. That was the reason why i adjusted in the first place - all my notes became harder to play after a while, and I suspected it couldn't just be my problem the notes were hard to reach. My left hand couldn't press the strings as fast as my right hand picked (I was playing fingerstyle) so the coordination error was the problem.

But one thing was the action was still lowered, and I guess the adjustment did work. My problem is the adjustment did not retain at the optimal level I wanted, which was the puzzling question. Why did the action increase yet again after the adjustment to the level I found best? Although the action did improve it wasn't what I was looking for.

One thing to note is my guitar had been left in an air-conditioned room at 25 degrees celsius for a long time. But when I adjusted the truss rod, it was also at 25 degrees.

One very important question I have is if I tighten the truss rod by a fair bit (until quite tight), will the action still be high? My hypothesis is this: I didn't tighten the trussrod enough, and after I played the song with the capo on right after I adjusted, the string tension increased above the normal tension the neck was used to, and so the truss rod got loosened again. Could this be the reason?

[zmf]

Originally Posted by chessmate99

I still can't reliably tell whether the neck is straight or not. How can I tell?

Not hard. Capo the 1st fret, hold down the 6th string on the 12th fret, and measure between the top of the 7th fret and the string. A recommended gap is around the thickness of a business card (0.005 inch).

Your problem sounds a bit like what happened to my wife's guitar. She stopped playing and left the guitar in a humidified case. It swelled, the action got ridiculously high, and a good luthier wouldn't touch it until it dehydrated.

If this has happened to your guitar, then the usual measures of relief, action, etc might not help. To check relief, try sighting down the neck to see if there is forward or backbow. If the neck seems straight, there's no point in playing with the truss rod.

Good luck with solving your problem.

[redir]

Originally Posted by Sonics

I suspect there is more going on here than meets the eye. The OP tightened the truss rod, then after a few hours the neck reverted to its original relief. The OP also detects no change in the 'tightness' of the rotation of the nut/screw.

Two and two usually makes four, but can anyone see what these two pieces of data indicate? That's why we need the input of an 'expert'.

A problem that is not easily solved over the Internet

[GHS]

You did not mention so I would suggest using a gauge to measure the distance from the top of the fret to the bottom of the low E string. Do this at the 2nd,5th and 12th fret. This way you have some exact way of knowing the change in string height with each adjustment made. Otherwise you are just guessing.