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I've previously asked about "heat treating" necks here and I've gotten some good advice. And now that I have met some people smarter than myself and have learned alot I can say for certain that heat treating is a bad idea and does not fix the underlying problem. Since I've been at my current shop I have consistently gotten instruments in with twisted and warped necks and a majority of the customers told me the same thing. "Another guy tried to fix it but it came back" and upon finding this website I now know why as this shop is maybe 45 minutes away from where I am currently.

http://www.warpedneck.com/

Just found it interesting that they have a shop dedicated to this method. Also that it advocates doing this repair in place of a neck reset, doesn't really fix the problem but still.

Agreed Dan. The ones I get in get the necks re-leveled or get new necks.

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I have used heat to get a neck straight temporarily then install carbon fiber rods to lock it down. Has worked successfully several times. Of course it requires the removal of the fretboard. I've got a couple of extensive threads over at the MIMF detailing these jobs. If anyone is interested I can provide a link.

I'd like to see those for sure. I like your idea of using it to make a neck straight before reinforcing it. That's an excellent application. But relying on it to straighten a neck that has no adjustable truss rod isn't a good idea, usually they just creep back to where they were before.

Here you go.

https://www.mimf.com/phpbb/viewtopic.php?f=8&t=5637&hilit=gibson+J45

So, how common are twisted necks? I get that they happen, but I just had a Taylor 110CE in with a slight twist, and I'd actually never seen that before. I actually thought it was an optical illusion at first because the nut was physically shorter on the treble side, but with the nut off it was clear that there was a slight twist. Nothing like what you show in those pictures though Barry.

I was able to make the guitar playable by dressing and levelling the fretboard, but it will be something for the customer to keep an eye on.

In my experience they are just the normal result of aging and the wood moving. Twist is something that you just deal with like any other aspect of owning and caring for a guitar.

On average I see 4-8 every 2 weeks. Sometimes mild sometimes insane. Lots of times it's just on instruments that are cheaper or just not maintained well. Usually the owners are told at GC that it just needs a truss rod adjustment which doesn't fix the issue and then they come by my shop.

So would a proper fix on a minimally twisted neck be dealing with it through levelling and dressing the frets taking the twist into account? Then milling the board flat when it's time to re-fret? But if its really bad ultimately dealing with it as Barry suggested above?

Yes that is a good fix when it's minimal. But when the twist is severe enough that it would require grinding the frets to pancakes then it's time to level/re-plane the board.

Have leveled a few and have had no other issues

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I don't see how you can heat the neck and not replace the frets.

Twisted neck is pretty major and if the twist is slight I prefer to just plane the fingerboard, but if you heat it to remove the twist it's hard to control where the neck will end up, and to ensure the guitar is fully playable I think it's still prudent to remove the frets and true the fingerboard before calling it good. Not to mention who knows if the frets will pop back up when heated?

In the MIMF post it seems clear the problem may in fact be caused by compression rods... it's not hard to over tighten them and they will eventually distort the neck especially if the neck needed a lot of correction (heavy strings for example, or bass necks). Not a bad idea to just use a double rod since they're not all that expensive and is easier to make/install if you really have to.

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We see perhaps one or two a year that have a noticeable axial twist..something more than what can be accommodated with minor fret dressing. An axial cyma curve or other minor curvature is not unusual, but not something we consider as a warped neck, given the total curvature is usually no more than 10-20 thousandths, and appears to us to often be more of a leveling issue with the board versus a neck issue.

In new construction, careful stock selection and use of a strongback when gluing up the fretboard to neck seems to avoid the issues that some builders report using waterbased glues. I know the boss briefly used epoxy glue for fretboard-to-neck glue-up a decade or more back, but the switch to strongbacks and hide or fish for the job yields a straight neck without the epoxy-related repair issues.

Taylor, Gibson, and Guild all used or currently use tension-style one-way truss rods, and we see little evidence to suggest they are any more or less prone to twist or axial weirdness than two-way rods. The worst we have seen in terms of sensitivity to adjustment are the dual rods in some instruments such as Guild 12 string guitars, but that seems to be more of a lack of knowledge on the part of the person doing the adjustment than any issue with the basic operating principle of the truss rod.

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If twist is caused by compression rods/truss rods then pretty much every single Gibson or Taylor would have twisted necks. Twisting is the result of wood being wood. If you leave a 2x4 or pretty much any construction wood it will twist/bow/wane all on it's own without any interference. The neck of a guitar is still wood, and the wood always thinks it's a tree so it will move as the seasons change as any other piece of wood.

The twist in the J-45 neck on the MIMF discussion was caused by extreme tightening of the truss rod. Apparently, someone was trying to do a neck reset with a truss rod adjustment. The over-tightening of the rod buried the nut/washer into the grain of the neck, going a little bit sideways (a little over 1/8") which caused an unbalanced condition that let to the twist. Once I removed the compression rod, a heat set and un-twisting allowed the neck to go back to its original straight configuration where the neck seemed to be very stable. Of course, the installation of the carbon graphite bars didn't hurt.

I have used a heat set to untwist a couple of other necks where I did not remove the fretboard or install carbon. They both seemed to have turned out well and they have not come back in for repair. This relies on the joint between the fretboard and neck to be softened due to the heat, then the neck is un-twisted and clamped into a slightly over set position, while the glue joint is allowed to cool. The fretboard joint appears to be more than strong enough to keep the neck straight. But I don't seek out these types of jobs because I have heard of lots of poor results from others experience with heat sets.

What are the epoxy-related repair issues? From other recent threads, it sounds like epoxy releases with heat more easily than hide glue, and without water so the fingerboard doesn't get warped in the process.