Is this method of neck reset physically possible?

[kizz]

Originally Posted by mirwa

Common sense and I repair guitars for a living

The clamping and steaming does not address the core issue

I would never have tried if it didn't somehow make sense. Wood can be bent with stream, it can also be straightened with stream. I agree that it doesn't solve the core issue, but that's not the point of this method either. Even neck resets in the traditional way do not last forever.

[Fawkes]

Let's have a look at this in the abstract, since doing so is now on the table as an option (this is a way of looking at claims that can be done well or poorly, so the real big question is: how to do it well?)

Heat-bending of wood is real and is commonly used in both new-making and repair of stringed instruments.

Neck rotation happens over time, and at varying speeds depending on the specifics. Only when it happens quickly absent maltreatment and/or on types of guitars in which it is not easily fixed is it considered an important flaw.

Neck rotation can be caused by leaving a guitar in an overly hot environment for too long, such as a car or some storage conditions. Cars can reach interior temperatures as high as 170 F and are often mentioned as the cause of a rotated neck.

John Miner, who is now retiring, has posted three videos about a method of carefully applied steaming and clamping which he claims resets the neck to a correct angle. In the four and a half years he's been doing it he has not had a neck come back up. Many commenters, at least one other Youtuber, and a few people on various forums have tried it with mostly positive results. In one instance failing to protect wood in uninvolved areas led to undesirable bending in the back plate.

No one has accused John Miner of specific instances of cheating people by selling a guitar with a short-term fix in which problems soon re-appeared.

How to evaluate his claims? If you look at the full context of relevant information it's clear that:

-some kind of procedure for heat-bending can be expected to reverse neck rotation.

-For instruments in which neck rotation took long enough for the guitar not to be considered a lemon, inexpensive restoration of correct neck angle that lasts nearly or as long as the original correct neck angle did would be a successful repair.

-John Miner didn't have much to gain by presenting the technique.

I think the preponderance of the evidence points to this being something worth looking into, although I am entirely sympathetic with the fact that professional repair people will need a long history of reliability and the development of a set of best practices before they trust this on a customer's guitar.

[rollypolly]

I think this DIY method could be perfect for old Yamahas or other budget guitars, if it can bring them back to playable condition, it’s a win win. Will I do this to my Martins, prolly not.

[JonWint]

Solid wood sides are bent at 350 to 400 degrees F. Glue releases at 150 degrees F. The only effect steam can perform in this method is to loosen glue.

[kizz]

@Fawkes

Good points.

[kizz]

Originally Posted by rollypolly

I think this DIY method could be perfect for old Yamahas or other budget guitars, if it can bring them back to playable condition, it’s a win win. Will I do this to my Martins, prolly not.

I think it´s primarily a method aimed at guitars where e.g. epoxy has been used and a traditional reset is difficult. I would never do it either if I had a guitar where the neck could come off without major problems.

[printer2]

Originally Posted by JonWint

Solid wood sides are bent at 350 to 400 degrees F. Glue releases at 150 degrees F. The only effect steam can perform in this method is to loosen glue.

I can not say every wood can be bent at lower temperatures, only bent about a dozen species, but I bend with a damp cloth over a hot pipe. The steam that comes off the rag is about the boiling point of water as far as my thinking goes.

[Fawkes]

...and bending wood to a new shape can happen across a range of heat vs. time. There is a method of bending violin sides called "cold bending" and it involves bending over time at room temperature.

Steam bending, which of course adds moisture to the wood, bends wood at the temperature of steam (around 212 F).

Note: I do not claim that what Miner is doing is the same as the pressurized steam process normally used for bending wood. But these are all data points that support the possibility that what Miner is doing actually works.

[Henning]

A guitar, tuned to concert pitch, is exposed to tensions by the strings. Those tensions are taken up by the neck heel block, which introduces forces into it, that over time causes it to alter shape. Imagine the effect of dryness and humidity changes temperature and naturally that will fasten the process of altering the shape of the neck heel block.
So why shouldn't it be possible to run that process "backwards"?
That's what being done in the video imho.
Introducing humidity in the guitar is a risk as this increases the risk for building mold. Bending back the neck, as this neck reset really is, is quite a time consuming process though not as labor consuming as a traditional neck reset.
I get to ask myself, will it be possible to "bend back" a sunken top too?
(A bridge rotating, now being cured by a 'bridge doctor'.)

[printer2]

Originally Posted by Henning

I get to ask myself, will it be possible to "bend back" a sunken top too?
(A bridge rotating, now being cured by a 'bridge doctor'.)

From my understanding the neck reset is needed when the top is folded on itself rather than it being a neck, heel block issue.

[phavriluk]

Fred, mine too. The only means of restoring neck/string geometry when the body changes shape is to relocate the neck. There's nothing wrong with the neck or the neck block.

[mirwa]

Originally Posted by kizz

I would never have tried if it didn't somehow make sense. Wood can be bent with stream, it can also be straightened with stream. I agree that it doesn't solve the core issue, but that's not the point of this method either. Even neck resets in the traditional way do not last forever.

Any steam that is introduced that is possible to soften the wood structure enough to straighten it out, is also more than sufficient to pop every glue joint in the neck socket, top, bottom and sides. These will release way before the lignen in sides or tops is soft enough to all ow the wood fibres to be repositioned.

the steam that he is introducing is inconsequential to the job, it is doing nothing, what is making it appear straight again is the forced clamping for a one month period (cold bending), again none of this deals with the core issue, so it will revert back to how it was originally over time again.

His process would possibly work long term on a guitar that had been left strung up in a hot car, not a guitar that over time has succumbed to failure from string tension

Traditional neck resets deal with the core issue, they set the neck in the position the guitar has come to settle in, sometimes a guitar may keep bending over time, but it is rare.

[kizz]

Originally Posted by mirwa

Any steam that is introduced that is possible to soften the wood structure enough to straighten it out, is also more than sufficient to pop every glue joint in the neck socket, top, bottom and sides. These will release way before the lignen in sides or tops is soft enough to all ow the wood fibres to be repositioned.

the steam that he is introducing is inconsequential to the job, it is doing nothing, what is making it appear straight again is the forced clamping for a one month period (cold bending), again none of this deals with the core issue, so it will revert back to how it was originally over time again.

His process would possibly work long term on a guitar that had been left strung up in a hot car, not a guitar that over time has succumbed to failure from string tension

Traditional neck resets deal with the core issue, they set the neck in the position the guitar has come to settle in, sometimes a guitar may keep bending over time, but it is rare.

I think most people agree that this method is for guitars that are either too cheap to invest in a traditional reset or are built with epoxy glue so it makes it almost impossible to take apart, I hardly think he would show the method on an old Martin or similar. But you are probably right, like others who have argued that it does nothing structurally. I tested it as I felt I only had something to gain, it straightened the neck about 1-2mm and did no damage and as written I sold the guitar later, so I'll never know how far it lasted, but maybe steam284np can tell about his experiences further down the road.

[JonWint]

Originally Posted by kizz

I think most people agree that this method is for guitars that are either too cheap to invest in a traditional reset or are built with epoxy glue so it makes it almost impossible to take apart, I hardly think he would show the method on an old Martin or similar.

The appropriate method for neck angle adjustment for epoxied necks is sawing the neck off and converting to bolts.

You can prevent tension-caused guitar body deformation by removing the tension (175 pounds) from your strings and reversing the load for the same period of time that they were tensioned. You would need a compression (175 pounds) apparatus between the nut and saddle (turnbuckle adjusted strut).

Impractical? Yes, that's why I leave most of my guitars tuned and am willing to reset necks if and when required. Normal maintenance that takes a couple of hours of work.

[kizz]

Originally Posted by JonWint

The appropriate method for neck angle adjustment for epoxied necks is sawing the neck off and converting to bolts.

You can prevent tension-caused guitar body deformation by removing the tension (175 pounds) from your strings and reversing the load for the same period of time that they were tensioned. You would need a compression (175 pounds) apparatus between the nut and saddle (turnbuckle adjusted strut).

Impractical? Yes, that's why I leave most of my guitars tuned and am willing to reset necks if and when required. Normal maintenance that takes a couple of hours of work.

Or a California neck reset...