Truss rod problems - wood compressing!

Natima

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Hi guys, I recently acquired a Les Paul with some pretty major neck issues.

As far as I can tell the truss rod is working, but the wood behind the nut is compressed significantly and has even caused a small amount of finish cracking on the back of the neck behind the nut. The half moon washer is pretty embedded into the wood and I can't remove it.

The result of this is that the neck is pretty massively bowed and I fear tightening the truss rod at all. I have the strings totally slacked and the truss rod totally backed off.

I have seen Mr Erlewines video on gluing a 3/32nd piece of rosewood into the cavity where the wood as compressed. Can anyone speak from experience how often this works and what other complications there might be?
 

Natima

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chasenblues

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Wow..
You might have a few different issue's going on, I would suggest finding a luthier to send it to.

I think that will need more attention than what you could pickup in a few 3-4 minute video's on youtube.(No offense meant..Just my .02c)

Did you know it was in that condition when you bought it?
 

Natima

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Nope. The frets are fine, the whole guitar is in cosmetically good condition apart from the cracks behind the nut. In fact, I'd say it's in excellent condition save for the obvious unplayability of it :C
The ad was in Japanese and something was mentioned about the neck, but they also said there is room left in the truss rod making me think that the cracks were purely cosmetic. I'm pretty sure they didn't explicitly say the truss rod was maxed and not straightening the neck. Because that's what's happening - tightening it has obviously just compressed the wood and not straightened the neck -.-

The nut is fine, just really tapered in thickness - just how it was made.
I apprenticed with a luthier in Oregon and went to Roberto-Venn after that, but I am out of practice and have no workshop space to speak of, thus, I am probably gonna take it to a repair shop here in London.

I have heard of and seen this issue before, but without the side-effect of finish cracks. I'm hoping a fix is possible.
 

ARandall

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The truss rod forces the neck up in the middle, not down. And at the adjustment nut there is very little movement of wood - the 7th-12th fret area is where I'd guess the most bowing force is centred. The force around the adjustment nut is along the line of the rod. It will certainly want to crush the fibres, but I can't see it causing the marks on the back.....that is most likely from a fall.
 

Natima

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You misunderstand.
The end grain where the half-moon washer sits has been compressed significantly.
The washer has become around 1/8 to 3/16 embedded into the wood.
The truss rod is not gripping as the half-moon washer simply sinks deeper into the neck and has caused the wood to bulge behind the nut creating the cracks.
 

Baylin

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Looking at the indentation in the cracked area of finish it definitely looks like some kind of impact damage as ARandall said. If it was from the stress of the wood compression from the adjustment nut, which I think unlikely, I would have expected it to belly outwards.

Is there any movement of those cracks in the finish if you try to flex the headstock whilst holding the neck?
 

six pack

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did you contact gibson they should fix that. you could put another waser on top of the old one
 

ARandall

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You're right, I am struggling to understand how the wood is bulging where it is (which seemingly is the headstock side of the TR) .....its not something that would happen under simple compression IME (which is not as much as many others here its fair to say).

If the bulge in indeed happening the way you say, this neck would seem to have the guitar equivalent of late stage cancer.
 

Bill Hicklin

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I would try as a first shot putting another washer on top of the old one and seeing if the rod will now start to remove the bow. Watch that crack carefully for movement as you tighten! I fear you may have a hairline headstock crack which is the real source of the problem, in which case it's Guitar Hospital for your axe.
 

ZWILDZR1

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My friend brought me his 91 Custom which was showing about the same amount of thread showing. I ordered a couple of the washers from Philadelphia Luthiers and when they came it only took one to fix his guitar so the truss rod would work ok and not risk bottoming out the nut and snapping off the end. I took the nut off and lubricated the threads then installed the second washer and it was good to go. Adjusted correctly the nut is now just about flush with the threads. On his guitar the wood really compressed from the other end. It looked much like yours does.
IMG_0092.JPG

You can see how far back the washer is on this Custom only the wood has not compressed from the other end.

Barbed half moon washer from Philadelphia Luthiers
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A link to them on ebay.

Barbed Half Moon Truss Rod Washer for Some Historic Vintage Guitars Qty 1 | eBay
 

rabidhamster

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That nut is just atrocious!!!! Or I guess pretty good if it was whittled with a butter knife...
That makes me suspect a twisty neck right there.

The headstock crack might be partially contributed to by the truss rod wood compression, but I think the cause was the hard impact to the back of the neck at those two indentation points above the crack. The compromised compressed wood in there will give way easier.
 

Paragon

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You talking backbow or upbow?

Almost looks like an impact mark on the back of the neck. From the reflection in the photos, it doesn't look to be blowing out. Perhaps just the finish cracking from impact.
I would think if the wood was stressed to the point of bursting out the other side the headstock would be having second thoughts about staying attached.
 

Ole'Lefty

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I have seen that kind of cracking on a dual(two) trussrod Guild 12 string on which the rods had been over-tightened. The fix on this is to pull the fretboard and completely rebuild the wood contact point of the trussrod washer, and then fix what are cracks in the WOOD which is likely a combination of a fall and abusing the trussrod. Those are classic headstocks cracks and I think after the impact, the neck became unstable and some idiot tried to suffocate it with the trussrod, cranking it down, trying to straighten a floppy headstock. Millions of guitar owners do not know, as previously stated, that truss rod adjustment affects the general area of 5-10 th frets. First thing to do, if possible is to get the washer out,[check it more by removing the nut-Looked again-oops, there is about a 1/4" of headstock below the TR access but sometimes the filler won't be ther and you still can see what is now the backside area of that nut.] BUT it looks embedded enough that the fretboard removal will be necessary. Without good tools, it should go to a luthier, even with your training. Could easily be $750 USD or more if there are any serious finish issues while removing the fretboard. You were outright cheated-very sorry. DO NOT just add another washer and go cranking on it.

I have seen a straight grained quality walnut shotgun stock come to pieces by someone who was just addle-headed convinced that the stock bolt had left hand threads and I was there and heard and saw it and nearly cried- it was a very high quality boxlock Belgian village gun- double. (cottage industry common in the Victorian and Edwardian eras). My almost vicious arguments against his assumption ruined a long time friendship in addition to the gun- I have it now after he tossed it down and I re-stocked it. I had to cut the bolt, and rethread for two metric sizes up after feeding silver solder into the diameter of the old screw . He had been using a screwdriver bit (credit for it being well-fitted) on an extension and a breaker bar. At least he did not strip-out and ruin the Snap on Brand 3/8 inch ratchet he had first employed. Irish whiskey was involved- would that better he had used it as a rust solvent, though I don't think even the best of them (in orange can- memory failure; it is a tapping fluid too) would have done it- worst I ever saw in 60 years of gunsmithing starting with Dad. We started my basic tutelage at age 9 with how to drift punch remove a Colt 1911 rear sight without gouging everything and I was so fascinated I was "off to the races."

Edit- Below the "V" shaped cracks, I see a straight-line, the lengthwise line about 1 1/2 inches long that looks like a scratch but would likely be a crack consistent with abusing the trussrod- trying to split the neck along its length. (the washer doing it, not truly the rod except for the rod providing the leverage[ remember that a thread is a spiral lever]One would hope it is a scratch in the finish, but I have seen too many cracks in wood under finish, and it just has that sad look about it.
 

THEBIGOLDDIRTYBIRD

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It looks like an impact fracture on the back of the neck but not necessarily. I think the rod is seized in the channel. That would explain why adjusting the truss isn't able to straighten the neck and why the washer is crushing the end grain. The force applied to the rod has nowhere to go if the rod is seized. It could definitely cause cracking on the back of the neck. The next step will be the end of rod breaking off or maybe the headstock. I had a similar problem with my Les Paul classic. It's on rod #2. I think it's time to see a Luthier. Don't want to be negative but I think it needs a new rod.
 

fumblefinger

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OK, I can't hold it anymore.

Yes, tightening the truss rod exerts upward force against the neck in the area of the 5th to the 10th fret or so. But it does so by pushing down against the wood in the area under the nut to the 2nd fret and the base of the rod. Newton's Third Law states "For every action, there is an equal and opposite reaction." The "opposite reaction" is the force I'm talking about. To dismiss the force under the nut/1st to 2nd fret, is to ignore basic physics.

This particular case does exhibit the dents in the area of the cracks, so it would be difficult definitively say why the cracks are there.

However in this thread (http://www.mylespaul.com/forums/luthiers-corner/335658-strange-fret-height.html), I still hold that the truss rod over tightening is what separated the headstock, as there is no indication of any sort of impact anywhere on the headstock.

Excuse me while I put on my flame suit....
 

Ole'Lefty

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I'm with you- "screw is a spiral lever"- but I am convinced there was a fall. The dents show the impact- the cracks occur at the classic weak spot. They do not necessarily superimpose. No fire suit ( I prefer Hinchman) needed. I think we all agree that this LP is in big trouble and piling on washers will make it worse. Time for "Headstock BCR Greg" or his equivalent ( if such exists where our victim resides). I would be thinking of a "contract" with a ninja in Japan-outright fraud; just shameful. It appears to be a Wine Custom so it is worth the repair investment- can't determine its vintage, but if the new owner's description of the rest of the guitar is not fueled by optimism or by comparison to the neck situation, it ought to be fixed ( and while it is in the ICU at the guitar hospital
, I personally, just me, would have it shot black.) I like Wine, but I am just a stubborn purist on Customs- probably because a nice Black Beauty is my ultimate desire in an LP. However, even in wine, it is basically a very fine guitar deserving of rescue and years of pleasure for the owner knowing he saved a special guitar.

And, if the new owner does not want to fight the fight, I am sure I and others would be interested in going the distance and PM's should be flying around.
 

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