Truss rod tightened to the max but neck still not straight

[Johnny]

I have an old Ibanez acoustic guitar and can’t get the neck to straighten out.
To ‘help the truss rod’ I have loosened the truss rod completely, gently pulled the neck back and whilst keeping the pressure have tightened the truss rod to the max but the neck still remains up bowed. Normally I can get a back bow, then loosen the rod until it’s dead flat.
Could someone explain what is happening here?
I this something that happens to acoustics over time or is it just a case where the rod was never installed properly from day one and the neck was never able to go straight?
Thanks.

[jjh]

I had a repair where I needed to adjust the truss rod past max if that makes sense I clamped the neck into the position I wanted it then tightened the truss rod and it held fine you may be able to do this if the nut isn't bottoming out on the thread.

[Nick]

One possible option is a broken truss rod, does it rattle when you thump the neck with the heel of your hand? Although if the rod was insulated properly from the factory, it may not rattle. Another option as JJH pointed toward is the adjustment nut has bottomed out on the thread, it's been repetitively adjusted in the past that the wood under the head of the nut has compressed so the nut has run out of 'adjustment'. Two possible options for you to consider.
A company like Ibanez would have built it to work right from the start so unless it's had a truss rod replaced by a third party then the chances of your last suggestion would be slim to none.
Does the rod adjust from the body or the head end?

[christian]

Hi Jonny,

I've stuck this problem a couple of times on repairs, i wonder what strings were on it, if it was a heavy guage over time it may have curved your neck, changes in temperature can also move your neck, poor neck wood ie not well quartered,maybe the truss rod isnt set deep enough.
To fix it you could try heating your neck with some lamps and clamp a straight piece of strong wood to your fretboard and place a shim at either end of the fretboard, put a clamp in the middle of the fretboard and tighten to counter the upward bow.Turn the lamps off but leave the clamps on leave it to settle over night.
hope that helps.

Cheers

Christian.

[Johnny]

Hi guys,
It adjusts from the head.
Yes the nut wont turn any further. (Like when a screw is screwed into a piece of wood and is flush with the wood. Anymore and it starts eating into the wood.) You can feel it has reached the end.

There’s no rattle and it does adjust, but only to that limited setting.
I’ve taken the nut off and lubricated it as well as the thread.

When you say "the wood under the head of the nut has compressed so the nut has run out of 'adjustment'"

So that's because the nut has nothing to adjust against?
Thanks.

[Johnny]

Could it also be that the wood is also compressed at the other end down inside the neck?

[jeffhigh]

I'd try an extra washer under the nut, to get you a little more travel before reaching the end of the threads.
You do have a washer under the nut at present don't you?

[Johnny]

I think I worked out the problem.
The neck angle is out.
I used a long steele ruler over the fretboard and the straightedge does not lay right on the top of the bridge. It falls short under it.
Is this assessment from a novice correct?

[Bob Connor]

Sounds like it may be the cause.

Can you take a picture of the neck with the ruler on it.

Regards

[kiwigeo]

If the neck has up-bow and youre laying a straight edge along it then be careful youre actually getting an accurate picture of the neck rake.

[Johnny]

Picture.

[jeffhigh]

Measure your neck for bow by holding down a string at the 1st fret (use a capo if you have one) and at the 14th and check at the midpont for clearance between the string and the fret.
It should be about the thickness of a thin business card.
This needs to be right and is all that you adjust with the trussrod, the neck angle is a separate issue.

[Bob Connor]

Sorry to be a pain but can we get a look at that straight edge sitting along the neck.

Regards

[Johnny]

The relief is .005". at 12th fret
Height at 1st stg is 1.5mm
6th stsg 3.1

I can take another pic but the straight edge is running in a straight line in the middle of the fretboard to the bridge
Thanks

[Bob Connor]

Need to know the relief at around the 7th fret.

[Johnny]

sorry, I meant to say relief at 8th ret.
On the 7th is the same .005" (using feeler gauge)

[jeffhigh]

If you have 5 thou relief measured at 7th with string or straight edge spanning 1 to 14 then the neck is in perfect adjustment.

You also have plenty of saddle height on the bridge

What actually do you feel is a problem with the guitar

[tim mullin]

Jeff is right, if anything your neck has too little relief -- less than 10 thou is asking for buzzes and rattles. The only thing you would accomplish by tighening the truss rod further is to decrease the relief, and yours is already on the small side.

Likewise, your action as measured at the 12th fret is not bad (although 3.1 mm for a 6th string is getting up there). And the pics of your strightedge against the bridge look fine to me, as does the general height of the saddle -- meaning that it hasn't been shaved down in a desperate attempt to compensate for insufficient neck angle.

So, what exactly are you trying to fix? Are the strings rattling against the body frets when you play up the neck (a ski jump effect when the neck angle shifts even a little)? Or are you trying to bring the action down? The truss rod has negligible effect on action -- that must be adjusted at the nut and the saddle

[kiwigeo]

I agree....from the info I'm seeing/reading the neck is ok. I prefer a bit of relief in my steel string necks rather than a perfectly straight neck.

[Johnny]

Well despite all the positive specs showing up, it still feels a little bowed or clumbsy.
Just doesn't feel right...
I was questioning the truss rod because I am normally able to creat a back bow bow but can't with this guitar.
Also regarding the straight edge, I picked this up from Frank Ford where hes says if the straight edge is not clearing over the bridge the the angle is wrong>
heres:

http://www.frets.com/FRETSPages/Musicia ... angle.html

Thanks guys!

[Johnny]

Ahh now the neck has pulled forward since I last checked. The relief is now measuring around 14 thou


I might go and meditate for a while

[Johnny]

What do you reckon guys?Just a weak truss rod??

[tim mullin]

What do you reckon guys?Just a weak truss rod??

I think most of us here might be a bit confused about what your issues really are. Perhaps the most useful piece of information you've given us so far is "feels a little bowed or clumbsy. Just doesn't feel right...". The most serious issue you've identified with your quantitative data is that the relief changed for no apparent reason from 5 to 14 thou. Neither of those figures strike me as way out of wack (as relief is quite a personal thing and dependent on playing style), but it shouldn't change for no reason, and a change as big as that would have been accompanied by a marked loss of tuning.

From my interpretation of the photo, your straightedge strikes the bridge about 1 mm low -- which is not so bad, given the usual ups and downs of guitars, and certainly not itself indicative of a major issue.

If we're to help, I think we need some more information:
1. What is your point of reference -- what do you usually play and/or build/repair?
2. Is this guitar exhibiting any buzzes or rattles? Under what conditions (what strings, fretted where?)
3. Where do you feel the neck is bowed?
4. How does it feel when you play with a capo on the first fret?
5. With that capo still on the first fret, fret the 1st string at the body fret (14th) and measure the clearance at the 6th fret (what we've been calling relief). Now, fret that same string at the LAST fret and do the same measurement at both the 6th fret and the body fret.
6. Did the action change when the relief went from 5 to 14 thou? (earlier, you stated 12th fret clearance of 1.5 and 3.1 mm for the 1st and 6th, respectively.) If it did, what is that action height now?

You see, I'm accepting that the guitar doesn't feel right to you, and maybe you need a odd-ball setup to feel comfortable, but I'm not yet convinced there's anything structurally wrong with the guitar, save that one remark you made about the relief suddenly increasing by 9 thou -- that's a concern, but even a weak or broken truss rod wouldn't show up like that.

[Johnny]

Tim thanks for the reply.
Lets simplyfy it.
The relief has moved and I can't any thing about it because the truss rod wont turn any further.
Surely with a guitar that has 'nothing wrong with it' I should be able to adjust the rod to have as much or as little relif as I want.I should like on other guitars ,be able to even create a back bow if I choose to.
So my question is why has the neck moved again and why can't I adjust it?
Cheers.

[Puff]

bein naughty here Tim but baritone guitar strings on a baritone uke could do that
Apart from that I am equally bemused.
Johnny you use the terminology that "the relief has moved". Meaning what please. That the depth centre of the bow has migrated up or down the fretboard, migrated and grown a higher action ....
For mine. Unstring it and start from scratch. If it comes in pretty close to the specs already given here then it ain't the weapon"s issue.