Refretting fret board issues

[Song Writer]

I am refretting an old classical. I've successfully pulled all the frets from the granadillo fret board without incident. But now, a straight edge and a feeler gauge indicates that I've got a .03 bow from fret 6-11. It's a fret board with black plastic binding. Can I sand down .03 into the binding, or block off the last 32nd on the edges of the fret board to preserve the binding and take down that .03 without removing the binding? Or do I bite the bullet and take off the binding?

[Silly Moustache]

I'm no luthier but I think that is often done. As long as you bevel the edge.

[redir]

I'm having a hard time understanding what you are saying but it's probably just me (block off the last 32nd on the edges ?). If what you want to do is just resurface the fretboard to make it dead flat again then yeah that's commonly done all the time and you would want to do it with the binding on. Because if the binding was off then it would be too tall when you re-installed it. No biggie either way but why bother taking it off?

Having said that 1/32 of an inch is not that much but if the fret slots were cut right to match the fret tang then you might have to reslot them. Usually there is enough fret slot depth for a resurfacing though.

[Rodger Knox]

There a chance that 0.03" was built into the fretboard, nylon strings don't usually pull enough relief. I'm assuming it does not have a truss rod, since you are contemplating planning it flat.

[cobalt60]

On higher-end classicals, a small relief is typically built in to the neck or fretboard. This can happen in a few ways, including a tiny bow or a sloped-down bass side from 9th fret to 12th, etc.

Cannot speak to the exact one you're working on, but it's possible that it's entirely purposeful.

[Song Writer]

This is not a high end classical, but a student model from the 70’s. The fret board from frets 1-5 is flat, and so is the area from the frets 12 on up. I assumed the bow was due to age and am not aware that it could be “built in” specifically for the area around frets 6-11. That seems odd to me, but I’m not a luthier.

[mirwa]

Typically, we remove frets, back truss rod off, engage truss rod back on just a smidgen, level the fretboard and then fret it.

If it’s an old guitar with value and fragile binding or inlays, we defret, set the neck dead straight using the truss rod, lightly sand the fretboardand then refret.

If it’s an old guitar with value and the truss Rod is already maxed out, we defret, remove the fretboard, reinforce the neck, refit the fretboard, wind the trus srod off, bring it on a smidgen, level the board and then fret.

If it’s a guitar with neck twist, we defret, string the guitar up on a duplicating jig, wind the truss rod off, engage it a fraction, set the jig to keep the neck in the same twist bend, remove the strings, remove the frets, level the board, refret

This is only some of the examples of ways we refret, many many more exist

Steve

[Song Writer]

Originally Posted by mirwa

Typically, we remove frets, back truss rod off, engage truss rod back on just a smidgen, level the fretboard and then fret it.

If it’s an old guitar with value and fragile binding or inlays, we defret, set the neck dead straight using the truss rod, lightly sand the fretboardand then refret.

If it’s an old guitar with value and the truss Rod is already maxed out, we defret, remove the fretboard, reinforce the neck, refit the fretboard, wind the trus srod off, bring it on a smidgen, level the board and then fret.

If it’s a guitar with neck twist, we defret, string the guitar up on a duplicating jig, wind the truss rod off, engage it a fraction, set the jig to keep the neck in the same twist bend, remove the strings, remove the frets, level the board, refret

This is only some of the examples of ways we refret, many many more exist

Steve

I am refretting a worn out classical that has no truss rod.

[John Arnold]

I'm having a hard time understanding what you are saying

+1. What do you mean by:

"block off the last 32nd on the edges of the fret board to preserve the binding"

??
It is possible to remove the binding, then plane flat and re-rout the binding ledge so that the binding height is uniform. But I would never go to that extreme on a guitar of this description. IMHO, the only reason to remove the fingerboard binding on this guitar is to deepen the fret slots, since I like to do that with a straight saw.

[Song Writer]

Originally Posted by John Arnold

+1. What do you mean by:

??
It is possible to remove the binding, then plane flat and re-rout the binding ledge so that the binding height is uniform. But I would never go to that extreme on a guitar of this description. IMHO, the only reason to remove the fingerboard binding on this guitar is to deepen the fret slots, since I like to do that with a straight saw.

Ok, as described above the bow is from the area around the 6th fret to the 11th fret. I've known for years that the intonation reeks in this area and my first thought was, "I need to chalk this puppy up and get a sanding block on it and true the fret board before I refret." But.....is that going to ruin the black plastic binding if I leave it on?

Oh, yes it is a cheap student model but I've got all the time in the world to work on it, so hey, I'm having fun.

[B. Howard]

Often when re-fretting we true the surface of the FB to remove any playing wear and any slight warping that has occurred over time.

Guitars without adjustable fret boards like classical or pre 90's Martins need special attention to set relief. On steel string guitars a technique called compression fretting is mostly used. This can be used on nylon strung guitars as well. Another easier option for a nylon guitar since the working tension is lower is to level the frets with the guitar "loaded". This is done by supporting the neck at the nut only with the guitar resting on it's tail and placing about 5-10 lbs. of dead weight on the shoulders of the body. This will simulate some string tension and and decrease actual relief when strung.

[Bruce Sexauer]

Some direct answers: If you are going to level the fingerboard, the binding is part of it and stays in place.

A classical guitar requires a little relief. Measuring relief BEFORE detuning and defretting is important. Then measure relief w/o tension, and again w/o frets. This gives you a chance of creating a fingerboard surface that will naturally result in the ideal for playing.

Assuming fret tang size and slot width are compatible, induced back bend from fretting is close to equal to the relief created by string tension on a classical guitar. The actual deflection at the nut caused by the 160 pounds tension of a steel string guitar is only about 4 pounds. Much less on a classical guitar.

My educated guesstimate would be to restrain the body on its back, put 2 to 3 lb pressure up at the nut, create a perfectly flat fingerboard surface, refret, and restring. If there had been any saddle height issue, the plane of the fingerboard relative to the saddle can be adjusted in the process enough to make up to a 2 mm difference at the saddle.

Have fun!

[Song Writer]

Originally Posted by Bruce Sexauer

Some direct answers: If you are going to level the fingerboard, the binding is part of it and stays in place.

A classical guitar requires a little relief. Measuring relief BEFORE detuning and defretting is important. Then measure relief w/o tension, and again w/o frets. This gives you a chance of creating a fingerboard surface that will naturally result in the ideal for playing.

Assuming fret tang size and slot width are compatible, induced back bend from fretting is close to equal to the relief created by string tension on a classical guitar. The actual deflection at the nut caused by the 160 pounds tension of a steel string guitar is only about 4 pounds. Much less on a classical guitar.

My educated guesstimate would be to restrain the body on its back, put 2 to 3 lb pressure up at the nut, create a perfectly flat fingerboard surface, refret, and restring. If there had been any saddle height issue, the plane of the fingerboard relative to the saddle can be adjusted in the process enough to make up to a 2 mm difference at the saddle.

Have fun!

Thank you Bruce. That gives me something to think about.

[MC5C]

This is where one of those fancy neck jigs would be interesting. First off, saying "bow" without saying back bow or forward bow is kind of irritating. Second off, is the bow with or without string tension? That's where I would be measuring and notating the neck with string tension (and before removing the frets), so I could at least make an informed decision about what happens after the strings are off and the frets are out. Then, I would look at how much things change with that simulation of string tension noted above. I might or might not leave that pre-load in when moving on, but it would definitely be a step I would take to let my understand what I needed to get relief in the ball park. I'd start by flattening the fretboard, probably add some fall-off above the 14th fret, depending on what I found from pre-loading the neck I might add some relief, I'd then install frets, dress and carry on. I have added relief by dressing frets, if it only needs a few thou.,, similarly I have dressed in fall-off when dressing frets in a set-up. Oddly, having written this out, this is extremely similar to the steps I take making a new neck. I do the preload stuff with the double-actuing truss rod, mind you, but when I used single acting truss rods I sure paid attention to possible back-bow issues.

[charles Tauber]

Originally Posted by MC5C

...probably add some fall-off above the 14th fret,

Just out of curiosity, and clarity, what do you perceive as the advantage of adding fall-off/fall-away to the fretboard of an acoustic guitar, steel string or nylon?