Changing scale length after the fact?

[dogboy]

Hello,
Reluctant luthier here. Spent the entirety of my “discretionary“ income over the last 37 years buying and selling (usually at a loss to entice or enrich the posabbility of a trade) guitars, banjos, fiddles etc. Always on the low end (sub 1k). Looking for the instrument(s) that would suit my nature and be physically comfortable to play. Well here I am all these many years later having found that I prefer old Kay and Harmony guitars because of the hefty neck profile and wider than 1 11/16” nut (when that combination is avaliable). Problem is that those instruments I am left with after selling off the few “modern guitars” owned (Larrivee D-09, Gibson J-60, Gretsch G5120) are in exactly the condition you would expect. Four of 4 need neck resets and fretwork.

When I bought these I had figured the lesser initial cost balanced against the greater comfort of the hefty necks would justify my spending a few $$ to have them rehab-ed (one at a time over a number of years) by a competent professional. Then 2009 happened and I am left looking at guitars that are increassingly less rather than more comportable to play in light of advancing age that I won’t make my original investment back on if I sell, and can not afford to send out for repair.

My dream guitar has always been a 40’s era J-45. Fat neck profile, 24 ¾” sacle, 1 23/32nds nut, and maple body if at all possible. Ain’t ever gonna happen, but as considerations progress regarding home repairs of the current crew it occurs to me to wonder if (aside from all the already inherent difficulties of making the currently necessary reparis as a total neophyte in a very small apartment with limited tools) if it might be possible to change the scale length as I make other adjsutments.

For isntance since I have to re-set the necks anyway, might it be possible to pop the fretboard (all are currently 25 ½”) and replace it with a 24 ¾” scale fretboard etiher by upon re-installation advancing it’s placement on the neck closer to the bridge in order to maintain that scale length, or (horrors) by cutting through the neck a few inches south (toward the bridge) of the nut and removing an inch or so of neck length (parts to be re-joined with carbon fiber tenons). Truss rods are not an issue for any of these.

All questions of sacrilege aside, would be interested to hear if anyone has tried this (changing scale length after the fact), and also any considerations re: scale length geometry that this proposal seems oblivious to that would preclude this entire endeavor BEFORE the 1st attempt. Thank you for your consideration, partience, and forbearance.

Fare well, db

[Rodger Knox]

Yes, it's possible, and there's several ways to do it.

The easiest way would be to leave the bridge where it is and set the fretboard based on the bridge location. That would leave the fretboard 3/4" short at the nut end, which is OK as long as it doesn't reduce the break angle at the nut below about 6°. Also, the 12th (or 14th) fret will not be exactly at the body join.

You could also set the fretboard so that the 12th (or 14th) fret is at the body join, but that would require moving the bridge. This way would also leave the fretboard a little short at the nut end.

Another way would be to set the fretboard based on the nut location, but that doesn't make much sense, the bridge would have to be moved and the fret/body join would also be off.

[Ned Milburn]

It is possible, but highly undesireable.

The bridge is positioned from the edge of the body with the 12th fret or 14th fret and scale length being the determining factors.

Roger points out possible options, but the ramifications of the modification you are considering include: different bridge position, different nut position, 12th or 14th fret no longer aligned with body.

[Rodger Knox]

Mr. Milburn is absolutely correct, such a modification will substantially reduce resale value. With an old Kay or Harmony that probably isn't much of a concern.

This would almost have to be a DIY project, having a professional make those modifications would cost more than the guitar is worth, and probably more than you could get for the guitar after the modifications.

[LouieAtienza]

The easiest solution would be to buy a capo, tune down a half step, and clap the capo on the first fret. Wider neck, shorter scale, and no mods!

[B. Howard]

Moving the bridge is not really an option. It needs to be placed not only over the bridge plate inside but also over the X brace at a certain point to interact in a certain way.

Leaving a 3/4 inch space above the fretboard at the nut would require either a 3/4" wide nut or a double nut type of arrangement to make it geometrically feasible. The issue isn't running out of break angle, it's the strings not clearing the original transition. They will be resting against the peg head face, a very bad condition.

Louie has the best solution to obtain the desired results as closely as possible.

[dogboy]

Hello,
Reality of my situation is that I have reached that ultimate termination of G.A.S. only possible through cessation of the ability (not desire) to purchase more instruments. Am of an age that if I were to lose the job I have now, another will never be forthcoming. That and the stagnation of wages over the last 6 -10 years leaves me with little or no wherewithal to purchase much of anything and certainly not guitars beater, dream or otherwise.

Actually encouraged however by the comments and info y'all were kind enough to leave. As I read it, there are 2 major concerns should this project be attempted on at least one of these (zero resale value) guitars. 1) Leaving the bridge in it's current location and mounting the new fretboard short of the current nut location raises concerns about the angle that the strings come off the nut headed for the posts, and 2) that the 12th/14th fret will no longer align with the edge of the body (although I am not altogether clear on why this is might be a problem).

Very practical capo suggestion appreciated. Don’t know if the fault is in my technique or something more vastly unfathomable, but I never get the same aural satisfaction when playing with a capo, as opposed to without. Would like to keep the option for that open string “zing” which the capo precludes (at least to my ears), although all things considered who knows what little more it will take to manifest my “final straw” and convince me to give up entirely. In which case (the black one over there) most likely will either indeed resort to the capo, or put all the gits in a pile and jump up and down on them all until my life is run out. We’ll see.

Thank you for your observations and time in. Much appreciated.
Fare well, db