Your guitar’s X brace is a crucial part of the top’s support system. An X that is loose in front of the lap-joint can promote a spectacular top failure, so it’s best to check on it every now and then, particularly on a 12 fret Gibson flat-top from the 1930s like this 1932 L-00.
Here’s the 1940s Regal X brace conversion that I finished up earlier this winter. I’ve finally managed to convince my daughter to let me take it back!
The guitar started as a ladder-braced instrument with Regal’s ‘Small Jumbo’ body that measures 15.5″ at the lower bout and has a fairly deep body depth. It’s a good-looking guitar but needed much repair to its original bracing, bridgeplate, bridge, and top, so was a good candidate for an x-brace conversion experiment.
The guitar’s neck and top and were pulled and all the top’s braces were removed. The top was originally about 1/8″ thick, so I opted to thin it to more of an early 30’s spec, and ended up at about .105″. After gluing a few top cracks, loose sections of back braces, and a couple of back and side cracks, I carved away all the excess back brace spruce to open up the back’s tone.
The top was braced similarly to a ’31 Martin OM, complete with early 30’s shaped scalloped Sitka braces and tiny stiff maple bridge plate. Some modifications were made to the layout to accommodate the guitar’s 000 scale length of 24.9″.
The top was reinstalled with its original binding and without any finish repair or touch-up. The bridge is a 1930’s proportioned small rectangle with through-cut bone saddle, 2-1/4″ string spacing and Antique Acoustic unslotted style 28 pins.
The frets and nut are new, and the guitar plays easily. The original Kluson tuners work well and are fitted with new Antique Acoustic buttons.
The guitar has a lightly-built tone, with lovely openness and warmth in its bases, strong and clean mid-range and trebles that are well balanced. The overall voice is something of a J-45 meets 000-18 and is quite unique among the vintage instruments that we have in stock. The neck has a round, chunky, almost-Banner-Gibson feel, with a 12″ fretboard radius, rolled edges, and a 1-3/4″ nut.
In the end, I discovered that converting ladder braced guitars to X braced guitars is something I won’t do with any regularity, as attending to the details the way I’ve become accustomed to in vintage instrument restoration is simply too cost-prohibitive. As a hobby, sure, it’s a great way to spend one’s time – but as a job, doing a conversion with the care and attention to detail that a pretty old guitar like this deserves is simply not a viable way to make a living! Still, this was a fun and worthwhile undertaking, and certainly a great distraction from the wintertime Covid blues!
In this video Mark discusses some of the unique construction details of an early sunburst 14 fret L-00 from 1933. An L-00 isn’t just an L-00… there’s always more than meets the eye!
A clean brace reglue is all about taking the time to set things up precisely. Gibson brace ends are notorious for popping loose, and getting them back down again can take some real coaxing.
In the case of this early ’50s J-45, the shrinking pickguard had cupped the top so badly that the upper soundhole brace, X brace, and a finger brace were all loose from the top and tightly sprung. The pickguard was removed, the top ‘ironed’ flat, and the braces are now getting reglued one-by-one.
It’s not uncommon to need to make custom brace-end gluing cauls that are specific to the guitar being worked on. It’s a lot of extra work, but a well-fit caul is critical to a clean end-result and a repair that will hold in the long run.
Custom brace-end caul
Mark offers some thoughts on cracks in the tops of vintage guitars. You’ll learn why they happen, which ones are more concerning than others, how to spot them, and what to do about them.
This kind of bridgeplate positioning is a regular sight in a 50’s Gibson.
Someone didn’t like their job all too much, I figure.
A lifetime later, these sort of idiosyncrasies are partially responsible for the tonal variation between otherwise similar Gibson flat tops.
This is a 1951 J-45 that’s on the bench for a neck reset and some requisite brace regluing.
The road to the modern Gibson flat-top acoustic began in 1926 when the L-1’s arched top was replaced with a flat, braced top. Those first flat-tops featured the familiar small and round L-body shape, a carved back, a long and narrow ebony pyramid bridge, and a unique early version of H-pattern top bracing. A year later the guitars had flat backs and the first sunbursts were being rubbed on flat tops.
By 1928, Gibson flat top designs had evolved into the L-0 shown here. The long and narrow ebony pyramid bridge was replaced with a stout, multi-layered rosewood one with interesting architecture and a 7th pin (more about these 7th pins to come). The H-bracing evolved as well, becoming slightly lighter and more flexible, with angles tweaked to improve mid-range presence, volume, and overall sweetness. The first adjustable truss-rods show up in flat tops in early 1928, and necks become a bit more comfortably rounded, narrower at the nut and more highly radiused at that same time.
It’s an interesting transition, and one that continued through 1933 when the first truly modern 14 fret steel string models are shipped from Kalamazoo.
Mark discusses the unique 1932 Gibson L-00 with 13-fret neck joint, and the specific considerations that went into its repair.
Nightshift guitar repair going on here with a 1933 Martin R-18 on the bench – the little sibling of Martin’s C-1 archtop.
Unlike the carved C-1, the R-18 has a pressed top that is just a bit thicker than a normal flattop top and features a beefed up X flattop style X bracing, complete with a little maple bridgeplate.
It is interesting to compare this model with Gibson’s flattop guitars that featured trapeze tailpieces and archtop-style bridges at around the same time.
Both Martin and Gibson were trying out bold new ideas in the early days of steel string guitar-making in the late 20’s and early 30’s.
Some top crack repairs are more involved than others. This is the Sat-on-at-a-party-long-before-Covid 1947 LG-2. Still a long, long way off from completion, but a little bit closer now.
Nothing terribly fancy going on here, but I think it looks interesting enough to share. The top cracks are being glued while the simple wedge system is pushing everything together; the clamps and 25 lb sandbag are keeping things properly aligned. The treble-side crack was done yesterday. It follows the grain at the outside edge of the pickguard to within 2” of the top, and all the way to the bottom of the plate.
