1930s National Triolian 4-String Resonator Mandolin

Last year I worked on the same-model mandolin that I picked-up in fairly-excellent shape. I promptly sold that to a customer/friend of mine out on the West Coast, however! Still, I always get the "resonator mandolin" bug because I love the sound. I've always wanted to do-up a 4-string version, however, and have drawn-up plans to make a solidbody one from time to time, but have never gotten around to it. Since I've been plinking-around on my electric 4-string, I've been thinking about it more.

As these things happen, however, I was offered this beat-to-heck Nat'l on email a few weeks ago and we ironed-out a price and it arrived last week. It had the aforementioned trouble of "a warping neck when tuned to pitch." Perfect fodder for a 4-string, I thought. It turns-out not only was the neck cut thinner (front-to-back) than the average Nat'l but it also had a half-detached fretboard -- so of course it was warping when strung-up. These Nat'ls have nearly 15" scale lengths (like a short mandola rather than a mandolin) and a regular set of strings puts a lot of tension tuned to full pitch. Most mandolins have scales an inch-plus shorter and that reduces a lot of tension compared to the Nat'l scale.

Anyhow, I did convert it over to a 4-string and did all of the other necessary repairs to get it up and going, too. I'm very happy with the result -- it has that super-sustained, effortless-volume, reverb-laden National sound to a T. Because it's a 4-string, the increased tension-per-string due to the scale length doesn't make it tougher to play, too, and the 4-string setup allows a jazzier/more-electric feel and ability to bend and fingerpick strings. It's fun. It also looks stellar with every bit of finish trying to flake-off, heh heh.

Repairs included: a neck reset, fret level/dress, partial fretboard reglue, mod to original nut, mod to original saddle/biscuit bridge, reinforcement/mod to dowel and mushrooms/island posts inside the body, cleaning, a new strap button near the heel, fill of the old extra tuner holes and screwholes at the headstock, new Gotoh "aged" Kluson-style tuners, resoldering of a loose back/side body seam near the endblock, and modification of the "bridge cover/wrist-rest" to a bolt-on setup. Half of it was off the coverplate already, anyway, so this made it easier to adjust the setup

Setup notes: it plays bang-on with 1/16" action at the 12th fret, a straight neck, and string gauges 32w, 20w, 14, 9.

Scale length: 14 15/16"

Nut width: 1 5/16"

String spacing at nut: 1"

String spacing at bridge: 1 7/16"

Body length: 13 1/8"

Lower bout width: 12 3/4"

Side depth at deepest: 2 5/8"

Body material: steel

Neck wood: hard maple

Fretboard: ebonized maple

Bridge: ebonized maple

Neck feel: slim C-shape, flat board

Condition notes: clearly, I've modified its saddle, nut, and tuner arrangement to a 4-string setup. It has a non-original strap button and tuners but is otherwise original. The finish is thrashed and has lots of worn edges, flaking-off paint, and tons of scratches, nicks, and small dings. There are no major dents like one often sees on hard-played Natl's, though. The body is steel. I did have to solder-up one spot on the back/side seam under the tailpiece, too.