Straighten A Bolt-on Neck With No Truss Rod

[Guest bartbrn]

OK, no laughing, now! Just for the heck of it, I picked up (for five bucks!), a First Act kid's guitar that I thought I might try to make into a traveler's guitar. It has a 19-3/4" scale, with 21 brass frets (and a plastic nut), and a tiny little double-cutaway body that's about 8-1/4" wide across the lower bout. 1 single coil pickup and a hard-tail bridge with adjustable saddles -- all typical chinese ironmongery. The neck is one-piece maple -- no headstock joint or separate fretboard, and NO truss rod. Unfortunately, over the length from the 1st fret to the 21st (12-3/4"), the neck has an up-bow of about 1/16th", and there's ZERO fretboard radius anywhere. I'm not too worried about the skinny little thing's fretboard radius (neck is 1-5/8" wide at the nut, 2-18" wide at the 21st fret, and pretty much 3/4" deep from heel to headstock). Oh yeah, AND the onboard battery-powered speaker is AWESOME! Just like a Marshall stack...

I know this is no treasure (though the First Act SFA and custom shop stuff is the bomb), but I'd like to save this poor little orphan -- without, of course, spending a significant chunk of jingle... it ain't worth it.

So, any hot tips on straightening a bolt-on neck with no truss rod? If I was going to go so far as to use thicker fret tangs to help crank the up-bow out of it, I'd probably work a light radius on the fretboard while the frets are out. Yes, I have a little time on my hands -- recovering from rotator cuff surgery.

Thanks for your help!

Bart Brown

[ihocky2]

First thing I would do is pull the frets and see what the neck does, it will probably have a lot of back bow. Then I would sand it flat and refret with the proper tang size for the slot width. Thicker fret tangs are usually going to create more back bow, so you would actually want thinner tangs. But if you have that much back bow while strung up, you are probably going to have a lot more without tension on the neck unless it is a very stiff neck. The best way to remove that is to flatten then neck. Then you can work from there. If you don't have it yet, I would either buy or borrow a copy of the StewMac fret work book by Dan Erlwine. He works on several Martin guitars with adjustable necks, you can pick up from where he is going.

[Guest bartbrn]

Thanks for the info -- perhaps I got the terminology wrong: this neck has "up-bow," in other words, looking at the side elevation of the neck, with the frets facing up, the fretboard side is slightly concave (a straightedge laid from 1st fret to 21st fret shows the middle frets with a gap to the bottom of the straightedge of about 1/16th"). I was hoping A somewhat thicker fret tang would incrementally "wedge" the neck back to some semblance of straightness.

And what do you think about a mild (12" to 16") fretboard radius?

I have Erlewine's general repair book, guess I'd better pick up the fretwork volume, too.

Thanks!

Bart

First thing I would do is pull the frets and see what the neck does, it will probably have a lot of back bow. Then I would sand it flat and refret with the proper tang size for the slot width. Thicker fret tangs are usually going to create more back bow, so you would actually want thinner tangs. But if you have that much back bow while strung up, you are probably going to have a lot more without tension on the neck unless it is a very stiff neck. The best way to remove that is to flatten then neck. Then you can work from there. If you don't have it yet, I would either buy or borrow a copy of the StewMac fret work book by Dan Erlwine. He works on several Martin guitars with adjustable necks, you can pick up from where he is going.

[Metalhead28]

I would first of take note of the amount of up bow, and also what string gauges are on it.

Then I would remove the strings and record where it is in terms of bow, then remove the frets and record where it is, just so you have as clear an idea as possible of what you need to accomplish.

Thicker fret tangs will force it into more backbow, but it's sort of trial and error to make sure you've picked the right size to go with.

[Geo]

You could probably strike a balance here... refret with thicker tangs. If this is too much backbow, use heavier strings. Pretty crude, but I bet you could get it into decent shape using frets and strings as your "truss rod".