1931 National Duolian Resonator Guitar

The steel-bodied Duolian was National's answer for a "downmarket" single-cone guitar. This one is from early in the production (they "came out" in 1930) and sports the earlier 12-fret body and flat-cut f-holes. Its original finish was "green frosted duco" which is a crystalline-looking bit of fancy stuff but that's been worn-in all over on this guy to produce a "rich rustbucket" effect. It now looks more like something that's trying to camouflage itself with woodland surroundings.

This came in with a lot of funk attached: it needed a total teardown, the fretboard needed regluing on about 1/3 of its length, the biscuit (bridge on the cone, really) needed a new saddle, the tuners needed overhauling, the frets needed work, hairline cracks on the board needed filling and stabilization, and a number of setup issues needed to be worked out internally (the neck is supported via a long oversized dowel in these like in a banjo rim).

After surgery, though? What a kick. It's just plain fun!

I make no bones about admiring old Nationals: there's just nothing like them. When they're properly serviced they can play the role of an archtop guitar's low-end bark/cut, fingerpicked spanky blues machine, or pseudo-clawhammer banjo-thing. If you're adept enough, too, you can coax some warmer/sweeter flattop strummy sounds out of them as well.

Oh, and don't forget slide... though that's to be expected. The other thing to be expected, too? Ear-splitting volume if you want it. You have to get used to a certain amount of restraint when you play a National like this.

While everything on this looks original, it's not quite. The bone nut is one I scrounged from my parts bin and belonged to a 30s Kay-made guitar to begin with but it sure did fit just right (and looks the part).

The tuner shafts and gears are original, though I've modified some alternate baseplates from my parts bin to fit them. The originals were pretty messed-up and this yields a "shaft under knob" setup which is better than the original layout (which would've had that order reversed) as it means that the string pull tightens the gear up with the worm rather than the other way around.

Note also the "stamped" National Duolian script in the headstock. I believe this was only used for this year and maybe 1932. There's a C-series serial stamped at the headstock "top."

The original "ebonized" maple board is worn-in and pitted from frets 1-5. The frets themselves were a bit worn, too, but a level/dressing got them going just fine with many more years of play left. Action is spot on at 3/32" bass and 1/16" treble at the 12th fret, strung with 12s.

The dots are ivoroid celluloid per the usual National flavor. The neck itself is mahogany and totes a 25" scale length and 1 3/4" nut. It's got a flat-profile board but the back of the neck is a medium C shape not unlike a 40s Gibson.

When this came in the end of the fretboard had a big old screw in it. I've since filled the crack/hole from that little addition and touched-up the board.

I string resonator guitars with the strings passing under the tailpiece rather than over. This improves back-pressure on the saddle and also affords me the possibility of muting the afterlength with some foam stuffed-up under the tail... which I have done.

Note that the body hardware is all original except for one of these coverplate screws.

Update March 25: I bought this from my consignor a little after posting (I love Nat'ls) for the first time and immediately after added this strap button near the heel for live shows. It actually goes right into the dowel and, aside from being really sturdy for your strap, the addition of a stabilizer into the dowel right at the neck joint helps keep the instrument more tuning-stable vs. most old Nationals as well (which, if you know these guitars well, tend to wiggle a little at the neck pocket if you get carried away during a show). As a historical side note, during the 50s and 60s when Nat'l-Dobro revamped the wood and steel-body lines, they added a screw/bolt in the exact same place. I can always take this out per customer request and fill... but I think it's awful useful for live/practical use.

Plenty of battle scars...

Here's where the guitar got a big old "bump." It's not so bad on the top edge...

...but at the bottom the seam sprung a little. I've backfilled it with some solder and then sanded/polished off just to keep any sharp edges from protruding and to remove any chance of weird rattles.

Here are those cobbled period tuners! The important part is that they look "fair enough" and work just fine.