1920s Harmony-made "Lindbergh" 00-Size Flattop Guitar

Most of these Harmony-made "airplane bridge" guitars seem to have been made in the late 1920s and bear the Sears "Supertone" branding. This one bears some sort of confusing label in the soundhole but is clearly of the same general style and I've worked on three "airplane bridge" tenor guitars from the same time and a few ukes that feature the shape. I've seen some of these guitars with much fancier trim and a few rare examples sporting koa back and sides, but this one is more typical and has lightly-figured mahogany on the back and sides, instead. This one probably dates from just before 1930.

It's a 00-sized guitar wtih a 14" lower bout, so it's clearly "concert" in size as opposed to the average 13" lower bout "Harmony parlor shape." The scale length is also longer at 25" compared to the more-usual 24" on Harmony 12-fret guitars. The build is much the same as those parlors, however, and is super-extra-light with ladder bracing throughout. Harmony parlors, even strung with 10s, tend to have pretty dramatic weather-shift problems due to that bracing, but because of the way the long "airplane bridges" reinforce the top, some of the bellying and "doming" is mitigated and stabilized.

That "airplane bridge," though, by the way? It's "in honor" of Lindbergh's flight across the Atlantic. I'm assuming it was a pretty neat and easily-hit marketing gimmick, too, as Harmony used it for most of a decade after introducing it!

This nice, rare old box was sent-in by a repair customer more than a year ago, and after much effort I'm happy to say it's finished. Repairs included a neck reset, fret seating and level/dress, replacement binding on the neck, several seam repairs, hairline crack cleating/repairs, brace replacements on the back and top, saddle fill and re-cut for compensation at the bridge, a good setup, and replacement ebony pins at the bridge and endpin. All done-up it's playing on-the-dot at 3/32" EA and 1/16" DGBE action at the 12th fret and sounds gorgeous as a fingerpicker -- a lot like those "usual Harmony parlors" of the 1920s but with the flaws in the tone and handling ironed-out.

The top is solid spruce, the back, sides, and neck are solid mahogany, the fretboard is dyed maple, and the bridge and headstock veneer are rosewood. The nut is bone and both the original and my new saddle are bone as well.

Note the Harmony "swoop" to the top of the headstock. Also note the line below the nut on the fretboard. This was used with a Hawaiian-style extender nut for a long time. I'd hazard to say that's how it was always played, as many of these were.

The pearl dot at the bottom of this picture replaces a missing diamond inlay. The neck binding would've originally been multi-ply black/white, but the original celluloid stuff is so darn thin it's often very difficult to re-bind these with anything similar in spec. This came without binding so I needed to do something.

I chose to use some 1960s Harmony binding (amazingly, the correct height and width) from a Sovereign 12-string that was in recently, and I've known Harmony to mix black and white bindings on the same guitars at the time so it looks natural to me. It's also a bit like a kid giving his pops a kidney transplant -- in my harebrained way of thinking.

Note the discoloration around the 12th fret on the board. These stained/dyed/ebonized-maple fretboards get mealy and very brittle as they age. During the reset the extension actually split into a couple of pieces as it was lifted, and there was minor chip-out in that area that needed filling. I'm always leery of having to take this stuff up because it can be quite the hassle to preserve it.

Because these were upscale for the Harmony-made line, the trim is elegant and Martin-esque. They're classy guitars.

5 of the 6 original pins were left, but these new ebony ones are in far better condition for regular use. I filled the original (straight) saddle slot and then cut a new, compensated slot and made a new, compensated, bone saddle for it. There's enough height after the reset that adjustments to the action should be easy down the road.

Just like Gibson Kalamazoo products, the tops on these old ladder-braced guitars always belly or dome -- which is most of the reason they need neck resets. Because of the long bridge, this one domes-up, which is what I prefer to see as it's more stable in service than a bellying-behind issue.

The strings are 48w, 38w, 28w, 18w, 14, 10, by the way -- though it'd probably enjoy 46w, 36w, 26w for the EAD as well. I would under no circumstances string these guitars with anything heavier.

It's hard to see in the photos, but the back has some nice figure to it.


George said...

Hi Jake - What are the nut and bridge spacings?



Chris Debarge said...

You say never use strings larger than .010 on these. Good advice I'm sure, but what would they have originally been strung with? Thanks!

Nicholas Ratnieks said...

According to a knowledgeable chap on the Unofficial Martin Guitar site, the Harmony "Aero" bridge was announced to the trade two weeks before the Spirit of St Louis took its first flight- let alone crossed the Atlantic. The bridge was fitted to some new Roy Smeck instruments. Of course, the epic flight of Charles Linbergh was a very fortuitous development but flying was all the rage at the time as anyone that has read Bill Bryson's book "One Summer: America, 1927" will know. He misses out the Hawaiian guitar boom in the book- a major lapse! Quite frankly, I thought I knew plenty about the 1920s before I read this eye-opening book!

Jake Wildwood said...

Chris -- beats me what they were originally strung with -- gauges vary from something close to regular "11s" and "12s" as far as I've seen from taking them off of old boxes -- with tension somewhere between, too. Add to that a propensity for higher open Hawaiian tunings and you can see why so many of these old guitars are trashed! The bracing on these is, pretty much, lighter than your average fan-braced classical... which is why you can expect the top to dome so much on them as you bring them up to pitch.

Jake Wildwood said...

Nut is 1 13/16" wide and spacings are: 1 5/8" nut and 2 1/4" bridge.

George said...

Thanks, Jake. That's the third clip I've heard of that guitar, I think they sound great. Carl Bludts (daddystovepipe) and Paul Brett have clips on youtube.