Re-radius fretboard w/out relief adjustment

[arficus]

I need to refret my Kalamazoo Oriole. It has been well played, and apparently for some time by someone with long fingernails judging by the large divots in the fretboard. I'd like to sand/re-radius the fretboard. It may or may not have truss rod(?), but either way there is no adjustment. How do I approach sanding the fretboard on such an instrument when considering relief? Just make it flat (lengthwise) and assume/hope that string tension will produce an appropriate amount of relief? Or?

[CowhornShoehorn]

Yes, string tension will produce relief. If your guitar plays fine as it presently is, I’d be inclined to leave it as is. Frets jobs are complicated making this a difficult question as there are many factors to consider. If you decide to do the work you describe, sanding and radiuing the fingerboard flat would probably be the safest approach IF you want to maintain your current setup. Even then, you’re likely to run into some bumps along the way and if you haven’t already I wouid recommend looking into instructional materials on line (online courses, Frets.com, youtube, etc.) as well as refretting and more detailed and comprehensive repair books at the usual lutherie supply houses.

[JonWint]

What is the relief when strung? and unstrung?

Are you planning to sand out the divots or filling and leveling?

What is need to re-radius? Are you changing the radius?

If the relief is much greater than 0.000" when unstrung, use a 4" long radius block.

[arficus]

Originally Posted by JonWint

What is the relief when strung? and unstrung?]

0.012 strung, 0.004 unstrung.

Are you planning to sand out the divots or filling and leveling?

Divots seem too deep for sanding, don't think I'd want to take that much mass off of a neck that doesn't have adjustable truss rod (or may not even have a rod). The rosewood is so aged looking I imagine that any filler I might concoct out of rosewood scraps and CA would have a drastically different appearance so was planning on leaving them as is.

What is need to re-radius? Are you changing the radius?

I believe it came with 12in radius. A 12in gauge rocks and a 10 shows light everywhere along board (except at very end closest to saddle where 12 fits), but both rocking and gap happen to varying degrees so I thought it might just be good practice to sand board with radiused block. Perhaps it would be better to just leave board as is? My main mission here is a refret (frets are around 0.032 and still grooved).

If the relief is much greater than 0.000" when unstrung, use a 4" long radius block.

What is the intention of using short block? Being able to selectively target areas of the board for removal?

Thanks,
Ethan

[JonWint]

Originally Posted by arficus

0.012 strung, 0.004 unstrung.

Looks like you need to install neck reinforcement or plane the board to correct relief.


Divots seem too deep for sanding, don't think I'd want to take that much mass off of a neck that doesn't have adjustable truss rod (or may not even have a rod). The rosewood is so aged looking I imagine that any filler I might concoct out of rosewood scraps and CA would have a drastically different appearance so was planning on leaving them as is.

Check out Frank Ford method: http://frets.com/FretsPages/Luthier/...boardivot.html You can try amber CA and sanding dust or just live with the divots.

I believe it came with 12in radius. A 12in gauge rocks and a 10 shows light everywhere along board (except at very end closest to saddle where 12 fits), but both rocking and gap happen to varying degrees so I thought it might just be good practice to sand board with radiused block. Perhaps it would be better to just leave board as is? My main mission here is a refret (frets are around 0.032 and still grooved).

It might be variable radius. For light sanding you could use a flexible block.

What is the intention of using short block? Being able to selectively target areas of the board for removal?

Provides more contact with a high relief board. For 0.004" relief any radius block should work.

Thanks,
Ethan

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[arficus]

Originally Posted by JonWint

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neck reinforcement?! Isn't 0.012 well within spec for a strung acoustic guitar?

[JonWint]

0.004" to 0.010" is recommended range.

[redir]

The problem with starting out flat is that you may end up with back bow. When you hammer a fret into a fret slot you put forces on each side of the kerf essentially expanding it open a little bit. This adds up and can cause back bow. This is sometimes intentionally done to correct too much forward bow and the technique is called compression fretting.

The way to avoid it in your case is to either, or both, guess at how much forward bow to plane into the surface or make sure your fret tangs are perfectly fitted to the slots so you don't have to hammer them in hard. Just lightly tap them in and glue in place. Thin CA is a good choice of glue.

[arficus]

Wouldn't the relief expected after refret be about the same as now if the new frets have approx the same tang width as what's coming out?

Originally Posted by redir

The problem with starting out flat is that you may end up with back bow. When you hammer a fret into a fret slot you put forces on each side of the kerf essentially expanding it open a little bit. This adds up and can cause back bow. This is sometimes intentionally done to correct too much forward bow and the technique is called compression fretting.

The way to avoid it in your case is to either, or both, guess at how much forward bow to plane into the surface or make sure your fret tangs are perfectly fitted to the slots so you don't have to hammer them in hard. Just lightly tap them in and glue in place. Thin CA is a good choice of glue.

[redir]

Originally Posted by arficus

Wouldn't the relief expected after refret be about the same as now if the new frets have approx the same tang width as what's coming out?

Yeah in theory and if you did nothing put pull the frets and refret with carefully measured frets that fit but once you re-sand and re-radius the fretboard you won't have the same geometry.

[EZYPIKINS]

If you need frets, then by all means, do the do.

Just an FYI. You can plane a fretboard, fret by fret. By scraping with a good sharp razor blade.

Allot less intrusive.

[arficus]

Originally Posted by EZYPIKINS

If you need frets, then by all means, do the do.

Just an FYI. You can plane a fretboard, fret by fret. By scraping with a good sharp razor blade.

Allot less intrusive.

Given the current relief (0.012 strung, 0.004 unstrung) I suspect a flat fretboard would give a good strung result. Any reason not to use a radius block to "plane" the board?