Is It Possible to "Fill In" a Nut Slot to Start Over? UPDATE: Shaping the Nut Slot...

[Pete Andreev]

To make a long story short, I'm installing a new bone nut and I took a little too long trying to get the nut slot nice and flat. I couldn't get both sides of the nut to lay nicely in the slot and ended up filing too much. Now the nut slot is too deep...and still not flat.

It wouldn't be as much of a problem if I was using a nut blank but I got a pre-shaped Gibson nut from StewMac.

Is there a way for me to somehow fill in the nut slot so that I can start over??

UPDATE

The CA glue + baking soda worked like a charm...really, really great tip. Now I just need to make sure I don't file it too deep again, but I'm having trouble.

Any tips for squaring the nut slot up and getting it perfectly flat? I'm filing with a mill file and checking the fit very often...but I just can't get the ends of the nut to fit perfectly in the slot.

[Mike Kolb]

...and yet, so many factory guitars have the nuts glued-in on every available surface.

A few bad experiences (OK, more than a few) have taught me to score the bottom edge of the nut at the headstock with a razor-knife before trying to tap it out.

It won't eliminate any tear-out under the nut but it puts the brakes on chipping along the edge. 

[Peter Poyser]

Quote : "You may want the nut slot to be perfectly flat, but you don't need to have it that way." 

- Snipped for Shortness -

Quote : "Trying to fit a perfectly square and sharp corner into a perfectly square and sharp corner for the full length is a procedure for CNC machining, and a monumental waste of time for hand work."

- Snipped for Shortness -

Quote : "And, before you ask, NO I DO NOT THINK THE NUT NEEDS TO FIT SOLIDLY ON THE BOTTOM FOR ANY TONAL REASON."

 

 

 

For anyone who had faced, worked with and had to manage the mysteriously vagrant inconsistencies that Great Guitar Manufacturers have been responsible for Producing, over the last Centuries.

Franks Advice and Methodologies, will be instantly recognisable as an unsurpassable way of coping and dealing with the slight inaccuracies, inevitably and ubiquitously associated with Hand Crafted Instruments of Yesteryear.

However, as someone with "an interest" in Product Design and  Product Manufacturing, (of Premium Quality) for whom CNC Machining, and Robotic Devices are much more a Way of Life, and indeed as someone with a "Mind" for the Consumers Viewpoint.

 

 

I have to write, that I not only want the Nut Slot to be Perfectly Flat.

I Expect it to be Perfectly Flat, and take the View that by Default, Most Customers would be Reasonable to Assume it to be Perfectly Flat, on any New, Quality Instrument.

With complete respect to the Original Poster, I also take the view that the "I'd rather not buy a new nut blank..." approach is incredibly short sighted. Ask instead, "What would your Customer, Ideally Prefer."

When you go the extra mile, take the extra step, to "Ideally Satisfy your Customers Highest Aspirations", this is like Money in the Bank, it establishes Reputation and Superior Work demanding a Premium. It sets Yourself and Work apart from the typical "Botcher" and what is easily achieved by "Players Own Effort".

Today, Direct Drop In Replacement Parts are Available from Guitar Companies for Factory Parts like Nuts and Saddles. I can well imagine someone, on seeing a Shimmed Nut, fitted to their Precious Instrument, buying a Direct Factory Replacement, fitting it themselves, and never bothering to Darken the Door of what they presumed to be a Skilled Luthier ever again. Please do not think these comments are intended in any way at all, to be Scathingly Critical. Heaven Forefend, far from it, they are Purely Intended to Encourage the "Idea" of "Seeing Things the Way the Customer will See Them" and "Thinking the Customers Thoughts, before they even Think Them."

 

 

This is Exactly what Frank was doing when he shouted, "And Before You Ask" etc. (Snipped for Shortness).

A Good Luthier, has the Same Qualities you will always look for in a Good Valet or Head Butler, they have "The Gift of Anticipation", They Look Ahead, but from another's Point of View.

They Know what the people they Serve will Need, Want and Expect, even before any of these things have Occurred in the Minds of their Customers, and have Everything Done, just as they know, their Customers would have Ideally Desired.

Whilst I understand "The Sense" of Gluing with a Couple of Spots to the Fingerboard, whether or not I added a Couple of Additional Spots of a Much Weaker Glue to the Bottom of a Nut would specifically depend upon the Quality of the Wood End Grain on the Fingerboard.

Some Fingerboards have a Fine, Close Knit Grain of High Quality Wood, but I have alas seen many End Grains on Fingerboards, that to my mind left a lot to be desired with plenty of Airy Spaciousness between the Fiber's of the Wood. Usually this is the Case on Cheaper Instruments, made with Lower Quality Materials, but such Instruments Exist and need a Properly Appropriate  Method of Securing Nuts (via a Method that enables Removability). Broadly, I think it's worth making the point that Every Instrument Should be Assessed and Approached in a Manner Best Appropriate to the Specific Case in Hand.

Lastly, I have a Book just to the Right of my Eye. It is Entitled "The Book of General Ignorance" and its basic premise is that almost everything you can think of that is Generally Held to be Common Knowledge, is actually provable to be wrong. Clearly, I am thinking of Frank's Comment regarding the unnecessary "Need for a Solid Bottom to a Nut" presumably  for the Transmission of Vibration. Whilst I have no reason whatever to disagree with his comment, Personally I would exercise caution in regard to Restating It. My reason, is the Absolute Over Confidence in their Own Knowledge and Wide Spread Opinion, of many Guitar Players of Average Ability who appear to have "No Ears to Hear With",  and the widespread prevalence of "Common Sense Knowledge" as my "Book of General Ignorance" tellingly reveals.

Photography is a Life Long Hobby of mine, and I can vividly remember a Store Manager, a man I knew to be Most Knowledgeable and Experienced, get into an Entirely Unnecessary,  Heatedly Blazing Row with a Customer. Over something completely inconsequential that she Stated (perfectly reasonably as a typical, average consumer) which was Factually Incorrect. I Actually Believe there will be many, many Guitarist's, that will take (with all probability, completely and utterly incorrectly) a completely opposite view regarding the need for a Nut to be Solidly Secured (Glued) on its Base to the Headstock Wood, and would Disagree and Argue Vehemently about that. All I'm writing, is that unlike my Photographer Friend (who didn't make the Sale), it is best to Correctly Assess the Psychology of the Personality you are dealing with, and Avoid Allowing, Any Argument to Develop about such things, because Guitarists in Particular, are Incredibly Conservative, and in General, Absolute Suckers for Absorbing Commonly Held (but Completely Incorrect) Knowledge and would greatly benefit from reading "The Book of General Ignorance".

 

http://www.amazon.co.uk/QI-General-Ignorance-Noticeably-Stouter/dp/...

 

http://www.amazon.co.uk/product-reviews/0571246923/ref=cm_cr_dp_see...

 

"This book, along with the others in the series, is an amazing insight into the rubbish that we have been fed by parents and teachers. It highlights key points in history and facts that that we thought were true, blows them all away and starts from scratch. You might as well forget everything you've ever been taught and then read this book!"

 

 

I'm writing that Correcting Players Misconceptions with Plenty of Good Humour is the Way to Go.

But When it's the Case that their Ego, Self Identity and Feelings of Self Worth are Strongly Attached to and Directly Indentified with a Particular Brand of Musical Instrument.

Or Some Specific Issue or Musical Instrument Belief, regarding or associated to How Such Instruments Properly Function. Then there is a point at which it is probably better to be Sensitively Aware of their Personal Sensibilities, and allow the "Bliss of Ignorance" to those Bigots of Totally Polarised Opinion.

The phrase "Are you Teachable?" has I confess, at times fallen from my lips, and usually gives pause to such folk.

 

P

[Ned Knepp]

The first time I removed a nut, I wasn't aware that it should just knock off easily. I use the back saw from my Dad's miter box and cut down through the fingerboard next to the nut. I replaced the original, plastic nut with a walnut block that was roughly nut shaped that had some slots cut into it.  I didn't really think too much about string spacing or slot shape and depth. Oh yeah, I used the same saw to cut the slots. I never did get that "nut" to work properly... and for some odd reason the guitar never played in tune again.

THAT was a botched nut repair! Fortunately, it was on a guitar that had 3 screws (and 5 screw holes) on the back of the neck to "repair" the broken head. 

Personally, I don't think having a nut seat that is less that "perfect" is a problem. One of the things I learned from my teachers and parents is that "perfect" is a word, not a fact. The term lacks a universal definition and isn't really possible to achieve anyway, at least not if more than one person gets to vote.   Do I want a "perfect" guitar?  Not when it would almost certainly cost many time as much as the same guitar with a few, slight imperfections. I sincerely doubt if anyone could actually tell the difference anyway and THAT completely avoids the fact that perfection is totally subjective. I have "perfectly" good guitars that have flaws. The lack of "perfection" doesn't matter. 

A lot of what we do to an instruments when we build or repair them is compromise. That fact alone eliminates the possibility of true "perfection".  Good work usually means sweating the details but it also means knowing what CAN be done as opposed to what should be done.  One of the thing that I learned on my own is that all my work is transient, no matter how "perfect' the instrument is when I finish, it has already begun to change. Personally, I see no reason to demand a perfection where perfection isn't truly possible.   

[Russell Vance]

Hi Ned and all,

Yep, it's a tricky place to be philosophizing about technical procedures, especially when one person's idea of satisfactory is unsatisfactory to those who have the technical expertise of equipment to consistently achieve better results.  FF alluded to this in his reference to those who have CNC of maybe Plek machinery at hand to do these delicate jobs and achieve "perfection" as we know it.

I take a holistic approach to tone - and take the position that a guitar's performance is a function of the sum of all it's parts.  Obviously,  these parts and their quality and fit have a larger or smaller part to play in achieving good results but regardless, they all matter.  The best wood in the business can be defeated by poor quality components or workmanship on critical components.

In design, the quest for appearance is often at odds with functionality - our guitars have a relieved arris at the end of the nut and no  lacquer finish over the nut to neck juncture so it is easy to remove and replace the nut which is often in heavy service in our genus.  I liken flush and thick lacquer finished nut ends and edges to be  the same as welding on your wheel nuts - you know you are going to have to change the stuff one day and I don't believe I should promote a known problem because of traditional throwbacks.

Similarly, anything that encourages an air gap, such as described with a non conformal nut slot bottom, is prone to resonance around vibrating parts (like the strings directly above the slot) so why take the chance. If this is to be ignored, as is suggested, perhaps we should apply the same practices to the bridge saddles of acoustic guitars which have the same sound transmission function and medium, albeit to a greater extent.  

The design practice of removing all possible impediments to overall performance via a "sum of all the parts" philosophy is sound and I subscribe to it. 

Rusty.

[Andrew]

Could you describe for us (me?) this 'relieved arris at the end of the nut' perchance?

[Russell Vance]

The "arris" is the place (in this case) where the bottom edge of the nut end meets the end of the nut slot.   On a lot of guitars, Gibson comes to mind, this area is finished very tightly and smoothly so that the end of the nut and neck blend together  a thick layer of lacquer over the lot seals the deal.

Nice look I guess,  but as most luthiers know, a problematic design because invariably one has to slit the finish, or use a heated blade to break the lacquer to remove the nut.  The lacquer over finish also has a tendency to flow into the cracks and form a glue like bond so that removal of the nut can cause real damage to this area which necessitates a refinish.

Our design solution is to put a slight chamfer  (a narrow 45 degree edge) on the bottom of the nut and install it after the lacquer has been done.  That way popping the nut out is as simple as sliding a narrow chisel point under the nut and it separates quickly and cleanly.

Now, it's each to their own and guitarists are a conservative mob, especially the "coffee table look" guys and girls who will prefer the  look of the finished over nut end. So be it.   But, race cars don't have hubcaps and that's the way we think - performance trumps affectations every time.

Regards,

Rusty

[Andrew]

Ah, thankya. I wasnt quite certain what you meant by relieving the nut, but thats about what I pictured. For the record, Im in full agreement with you re not lacquering the nut. I think a closely fit nut looks better than one thats been buried in lacquer to make it flush anyway. It just looks right that way, to me.

I also took the hubcaps off my Impreza's winter tires. :P

[Peter Poyser]

Quote: "Personally, I see no reason to demand a perfection where perfection isn't truly possible."

 

 

Thank you for this viewpoint.

I can think of plenty of instances where for reasons of Cost, Time and Effort.

Both from a Clients Perspective as well as that of a Busy Luthier's Shop, sensible workarounds and dependable compromises are the order of the day, and we already have some Great Examples of that, in this Thread from some Fine Luthiers.

Inevitably, at times, Economical Reasons are a Clients Greatest Concern, but I'm also especially thinking of where the demands of a Desperate Travelling Working Musician are involved, and urgent, temporary work is required, purely sufficient to get them through the Immanent, Forthcoming Concert Dates.

As a case in point, I will never forget Andrew Lloyd Webbers, Cello Playing Brother, Julian, saying how as he Travelled from Region to Region on his first Concert Tour of America, his Instrument simply fell apart as the Heat and Humidity melted the Glue that held the Elderly European Instrument together. What a Nightmare for a Working Musician!

 

 

Quote: "One of the things I learned from my teachers and parents is that "perfect" is a word, not a fact."

 

 

Whenever I find a struggle with a Concept.

I've invariably found that returning to the First Ever Known Use of a Word to be both Helpful and Highly Revealing.

In England, (where the English Language was Invented), as indeed have been many basic concepts, (like "Gravity" for instance), many of the Words, Originate from Historical Latin, German and French Roots, and this is no exception, but the first ever known use of the English Word "Perfect" as an adjective, although obsolete, actually means:

 

I. † 1.  a. Of a legal act: duly completed. ME–M16.

            b. Of a foetus: fully formed. LME–M16.

            c. Grown up, adult (esp. legally). LME–L18.

 

Although in America, the bottom line for the Legal System is that "Justice Should Be Done", (and highly laudable I'm sure), in the English Legal System, its rather different, instead, the bottom line is that "The Letter of the Law Should Be Upheld".

In other words, in England, there is a "Specification" a "Detailed Formulation" that is Precisely Outlined, which must be Complied With, or indeed Fallen Foul Of. I think for anyone "Exercised over this Concept of Perfection", THAT is a most helpful way to view the Issue.

The Salient Point is, that this Facilitates a Method of Defining, what we Intend. We can Measure when we Comply and Detect we Fail to Comply with a Clearly Established Standard. When we Manufacture Products, Detailed Specifications of Parts are Ubiquitous, and indeed today in order to conform to Recognised Industry Standards, Manufacturing Processes as well as the Final Results, are Clearly Defined, Scientifically Measurable and even Regularly Audited by Recognised Independent Authorities.

 

 

But to boil this same point down, make it straightforward  for anyone to grasp, and directly applicable to any Jobbing Luthier or Small Workshop.

If you are aware of the Factory Action Specification and Tolerances of a Martin, Gibson or Fender Guitar and have a Ruler with which to Measure, then you can easily determine whether the Instrument has been "Perfectly Manufactured" at least in respect to its Height of Action.

Different Players, Perform with a Lighter or Heavier Touch, so for a Manufacturer, "Perfect Specification" Tolerances MUST take into account and allow for a Wide Discrepancy of Individuals Playing Style. Any Player might want a Lower (or indeed Higher Action if they prefer Heavier Strings), but there's no Argument that the Instrument is "Perfectly Manufactured", being within its Published Tolerances.

The Facility to Provably Demonstrate that as a Competent Luthier you can Measurably Improve that, to suit the Individual and Eccentric Traits of a Specific Player, is a Great Way to Fully Justify the Premium your Hand Work Costs your Clients.  It is an Unassailable Argument for the Worth of your Time and Effort. Although the Player should Instantly Feel the Difference, I think it's a Good Thing to talk about these Measurements to Clients. Use the Specifications to Demonstrate the Improvement and Value You Bring to Facilitate and Enable Their Higher Level of Performance.

Although there's No Innate Contradiction between these Two Strata's of "Perfection", (they are simply Ideal General Set Up Specifications for Most Players and Ideal Specific Set Up Specifications for Individual Players) To support your point, I'm thinking there are some hereabouts whom could justifiably put up a Big Sign in their Shop declaiming "Improving Perfection" and use it as a talking point to Demonstrate the Value that Luthier's Bring. 

I visited my Local Music Store a while back with a Long Straight Edge and a 64th" Steel Ruler. Every Montana Gibson in the Shop had "Perfect Geometry" and "Perfect Action", that Fully Complied to or Surpassed their Factory Tolerances.  So while its genuinely difficult for me to imagine that such a Renowned Brand could be Improved Upon. For those that palpably feel they could do so, Fabricating such a Sign might be the Next order of Business. Whatever will happen next? The Parsons St. Gibson Smoke Stack be Brought Down? :)

 

 

Quote: "race cars don't have hubcaps and that's the way we think - performance trumps affectations every time."

 

 

As always, I love your analogies.

And I completely accept your well made points.

A friend of mine is moving to RR Manufacturing in February.

Have you had seen the Centre Caps, that Don't Turn as the Wheel Rotates?

https://www.youtube.com/watch?v=YTsFKAy2MX8

 

Despite weighing 2,26 Tonnes.

The Fastest Model travels from to 60 miles an hour in just 4.4 seconds.

The car's 8-speed transmission gets information from a GPS unit so that it can select gears based on the road ahead.

It can downshift the moment a hill or curve is approached. That helps with both Performance and Fuel Economy. It's Another Form of Excellence, or if you like, "Perfection".

 

 

It just depends upon What the Criteria Is?

How you Define It? What Standards of Performance an Individual Player or Owner will Require. And those will vary from Person to Person and indeed, Instrument to Instrument.

Just to be Crystal Clear, for me personally, whether it's done by Hand or Machine, I prefer an approach to Guitar Repair, that for want of a better description, could be said to "Leave No Footprint", "No Detectable Evidence to an Experienced Eye" of any Work Having Been Done.

That doesn't mean I would argue for a moment with your Brilliantly Conceived Methodologies or indeed of those of Others, who for Sensible and Practical Reasons, take a Different Approach. All these Various Methods have their Place and will be THE Preferred Method or Approach under a Specific Set of Circumstances.

Generally Speaking, I want any Work to be Completely Undetectable, to anyone, unless they were Longstanding Workers at the Factory of Manufacture or So Intimately Familiar with the Materials and Processes used by the Manufacturer over a Very Long Period,  that it would simply be their Internalised Hunch that Work had been Done.

In other words, to all intents and purposes, "A Completely Invisible Repair".

 

 

Beyond that, and for reasons I don't properly understand, Guitarists in Particular (as Opposed to Bassists as Breed for instance), seem to get Hot Under the Collar about "Design and Technical Issues".

Obviously, Frank, by virtue of his rare use of Capitalisation appears to feel very strongly, regarding there being no need whatever to Precisely Match the Entire Base of the Nut to the Headstock or Glue the Base.

I have no argument with this view. Indeed, I Fully Respect and Appreciate the Depth of Experience, especially with the Vagrant Tolerances of Historic Models, that Lead Frank to Boldly and Clearly Declaim that Unequivocal Statement.

However, cognisant as we are, with the Internally Driven Mind Set of Typical Guitar Owners, I see this particular point as one to Avoid Discussion of with Clients. I see it as the Type of Issue, many would be Deeply Concerned about and Continually Obsess Over.

 

 

"Common Sense" would dictate to them, Otherwise.

 

 

For my own part, I don't believe it's beyond any Good Luthier, to be able to Fabricate a Nut that Fits Solidly Flush to both Fingerboard End with its Back and the Headstock with its Base, provided they are prepared to take the Time and Trouble, and the Instrument does not have Subversively, Inherent, Manufacturing Inaccuracies. Cue Franks Methodologies.

Because I want to leave "No Footprint" and most Manufacturers Glue both to the End of the Fingerboard and the Base to the Headstock, as I mentioned earlier a couple of spots in both places would be my Approach, quite apart from any Finish Issues. The point being anyone following afterward would find the Processes Used to have Authentically Duplicated the Standard Factory Methodology.

My Dentist, fitting a Cap or Inlay is capable of making such an Exact Filling to the Tooth, that even without any Adhesive one can Feel its "Perfect" Fit is such that it is Satisfactorily Flush with the Concomitant Surfaces. In Fact, She sometimes has a Devil of a Job to get the Cap Back Off in order to use the Adhesive and Cosmetically it looks "Perfect" too. I think a Well Made Nut, Goes into Place like That, Entirely Satisfactorily and would even Work Perfectly Well, just Held by the Tension of the Strings.

Of course I would Glue it in Place, but I appreciate this approach will not be for everyone. However I believe it's worth mentioning, specifically because it's an approach that is all the More Desirable and Necessary, as the Instrument you Work On, becomes Rarer, More Historically Significant, and of a Higher Monetary Value.    Enhancing and Augmenting that Intrinsic Value, (rather than contra wise, Directly Deprecating the Instruments Worth by Clearly Visible Practical Intervention), is I believe the Finest and Highest, Most Inspirational  Luthier Values we can Upwardly Aspire To, and as such, I would indeed Commend Them, to this Worthy House!

 

 

P

[Ned Knepp]

 I think a Well Made Nut, Goes into Place like That, Entirely Satisfactorily and would even Work Perfectly Well, just Held by the Tension of the Strings.

If a nut is properly fit, it will be pretty much as you describe and it will only need a bit of glue on the fingerboard to hold it in place. It's the poorly made nuts that need glue everywhere to hold them.   

As an aside; there a strong chance that the person you should think for your nice fitting crowns or fillings is a Technician.

[Pete Andreev]

I ended up taking Frank's advice...great solution. I took a few thousandths of an inch out of the center so that both ends fit tightly. I'm perfectly fine with the end result, especially with this being my first full nut installation done from scratch.

Although the superglue & baking soda worked great, I would like to know how to go about inserting a piece of wood to "fill" the nut slot instead of the glue solution like some had mentioned. The reason I avoided doing it this time was that I felt like trying to fit a piece of wood in the nut slot nice and tight was the problem that got me here in the first place...

How would you go about creating a new nut slot by fitting a small piece of wood in there?

[Andrew]

Well, that depends on how much material is being replaced..

But first lets clarify the semantics (is that the correct word? Im lookin at you Peter Poyser :P). The place where the nut is located would more 'correctly' be designated a nut shelf (if the nut is not captured by a headstock overlay) or a nut mortise/channel (if the nut is captured by a headstock overlay - I prefer channel). Anyway, to keep things simple Ill stick with nut shelf. Calling it a nut slot when the nut itself has other slots can lead to confusion, and Im pretty sure it already has.

So back to replacing wood...

If you or someone before you ended up removing more wood than necessary, but not so much as to significantly weaken the neck-to-headstock transition area (Im gonna say about 1/32" - much more than that and Id be a little nervous personally), then two approaches come to mind:

1) you could simply install a nut as normal, using a taller blank if necessary and not worry about the cosmetic issue of the nut bottom not being in line with the fingerboard bottom.
2) you could locate a piece of wood the same variety as the neck andmake a tight fitting shim with that, such that the grain runs the same way as the neck. Glue that in with the closest possible fit, trim as necessary, and then proceed with a finish touchup. Then install your nut and if all has gone according to plan youll have a repair thats hard to see and your nut bottom will be aligned with the fingerboard bottom as it once was. If all has not gone to plan, you might have made things even uglier than just living with a deeper nut shelf.

Now, say youve really removed too much wood, say 3/64", 1/16", or more, you have now structurally weakened this area which is already under stress and is also particularly susceptible to breaking in a fall or as a result of some other shock. The risk amount of weakness youve induced will depend on the wood type , grain direction, and original construction method of the neck. Either way, you end up inducing greater weakness to an area that was already vulnerable. Unfortunately gluing in a shim wont make it stronger again because you have cut through the long grain and are now presented with two end grain surfaces, and end grain joints have a hard time holding very well under the best conditions - subject them to tension or shocks and they nearly always fail. A good epoxy might have enough cohesive strength to improve the situation, but really the only way to get back to original strength would be to remove the fingerboard, cut off the headstock, and scarf in a new one, or get a replacement neck. Doesnt sound like fun to me.

So long story short, its best not to get carried away trying to square up a nut shelf. A fine shaving or two off the bottom wont hurt, much more than that and youre better off adjusting the nut to fit the slot rather than the other way around. This is why I never use pre slotted blanks and rarely use pre shaped ones. In repair situations you frequently end up needing the extra material to play with if you want a nice flush fit.

[Andrew]

It turns out Frank has done the very operation you're wondering about on this page: http://www.frets.com/FretsPages/Blogs/37D28/37d28_5.html

It also turns out the nut shelf he repairs was over-cut by about 1/16", so maybe I spoke too soon? Anyway, its still a lot deeper than I'd like to see.