ETUDE: Arched Plates: Bracing the Top

These 11 videos show how Ken braces the top of his archtops. Following the gallery of videos is Ken’s monograph on bracing, which gets into the history and how it informs his unique way of working with braces or tone bars.

KEN: Looking into the history of early archtops, it’s interesting to try to understand how braces evolved and came to be an integral part of nearly every archtop.

Strangely, braces were not part of the original Orville H. Gibson archtop designs at all!

O. H. Gibson’s “Fewer Parts Make A Better Instrument” dictum is quoted here in his 1898 patent. He explains that braces are not needed and names them first in the list of unhelpful interior reinforcements....

“Heretofore mandolins and like instruments have been constructed of too many separate parts bent or carved and glued or veneered and provided with internal braces, bridges, and splices to that extent that they have not possessed that degree of sensitive resonance and vibratory action necessary to produce the power and quality of tone and melody found in the use of the instrument below described…“

Even though he clearly states that braces are part of the problem, in at least one example of a guitar by his hand, he employs a light cross brace just south of the oval sound hole, see John Thomas’s x-ray image here (thanks again, John!).

This instrument was completed in 1898, the same year that his patent was granted, and several years before the Gibson company was founded.

It’s important to know that OHG’s main interest was the mandolin family, wildly popular in the US at this time, mostly played in the many community mandolin orchestras across America that provided entertainment and served as vehicles for co-ed meet and greets in the days before radio, movies, and recordings. In this popular context, the guitar was seen as less useful, less important, and made its appearance in the mandolin orchestras as a rhythm, not a soloists’ instrument.

Of course, the name of the new business itself told this story, “Gibson Mandolin-Guitar Manufacturing Co, Ltd.” Kalamazoo, Michigan turned out to be a great place to assemble a workforce of top-flight woodworkers, as it was then the nation’s Detroit of the horse drawn carriage. 

Not Motown, but Hosstown? Hooftown? It was home to many large carriage and furniture manufacturing firms that attracted talented artisans and craftsmen from far and wide. Immigrants from Northern Europe settled in the area, bringing their old-world training in woodworking with them. Before Henry Ford, wheelwrights and coach builders in the highly competitive carriage trade performed some truly spectacular industrial woodworking, and accelerated the development of cutting edge manufacturing. The carriage companies built everything from farm carts to presidential limousines, and were distributed nationwide by the expanding US railway system, beginning after the Civil War. The carriages, like Gibson’s instruments, were made mostly by hand from wood with a few metal parts. This labor pool had chops! It was also key that the material demands of carriage and furniture manufacture meant that locally harvested red spruce, birch, maple, etc, was cheap and plentiful.

Only a small number of the very first guitars made in 1902-3 were built to designs by OHG as it was quickly discovered that OHG’s eccentric building methods could not be translated to the factory environment. In the Gibson Company’s first 17 years before Lloyd Loar was hired to modernize and redesign the companies’ product line, their acoustic mandolins, archtops, and harp guitars were designed not by Orville, but by unsung (and un-named, as far as I know) employees of the Gibson Co.

Tasked with the job of designing for production and building an array of newly invented carved top instruments, they experimented and surely tried all kinds of things, trying to get the best out of their materials, just as every builder does. It’s fascinating to see the variety of approaches and designs that came from this time. Check out the stylin’ “Style 0”, then Gibson’s top-of-the line guitar offering.

In 1902, these were offered in three sizes, up to 18”.

It’s hard to imagine that they wouldn’t have tried a violin family style bass bar and soundpost as a jumping off place, and it’s not surprising that they didn’t employ a soundpost, but rather chose to add a treble brace, a mirror image to the bass bar, positioned under the feet of the bridge, in a bracing pattern we usually call ‘rail bracing.’

These rail braces were slightly splayed, so as to be further from the centerline at the tail of the body, just like the violin bass bar that inspired them. I confess, even though I know what you mean if you refer to these as parallel braces, it just bothers me, as they’re not. (Splayed bracing?) Backs of archtop guitars are normally unbraced, like instruments of the violin family.

Striving to optimize power and tone, and develop a buildable design, these innovators at Gibson must have decided that their best prototype instruments were equipped with rail braces. Their conclusion must have been that there was a clear benefit from bracing the top. It is a demanding, tricky, and time-consuming job to hand fit the braces to the interior surface of a carved top. Lots of skill and practice are required, and they wouldn’t have taken the time and trouble if they weren’t certain that braces were necessary. We agree! The proportions, the stiffness, and the locations of the braces are hugely important to the voice of the instrument.

The X brace made its first appearance in the archtop guitar in 1931, when the Martin Guitar Company introduced their first archtop offering, the C-1.

The C-1 was an entry level pressed-top archtop guitar model designed to compete with Gibson and now Epiphone, which had begun its bid for the growing archtop market in 1928.

Since Martin’s flat top guitars were X braced, it must have seemed a normal way to support the pressed top, although they soon switched to rail bracing for their upmarket carved top models.

For about ten years they explored the market, building some attractive archtop guitars in several styles, peaking with the F-9, their most expensive instrument, priced 25% higher than a D45!

I was surprised to learn that these sold very well, at times during the 30s representing 1/4 of Martin’s output. Although I’m no expert on this topic, I think Martin archtops are kinda cool, even though most of us wouldn’t think of Martin as an archtop company.

Production of these stopped in 1942, as they never did catch on in the archtop world and are now nearly unknown to most folks. Here’s a great site for a deeper dive into this obscure corner of archtop history: http://vintagemartin.com/archtops.html

The next X braced guitar was Gibson’s Super 400. This impressive 18” ultimate over-the-top-of-the-line flagship was their first X braced archtop, appearing in 1934. I think it’s fair to say that the origin of our field’s current obsession with bling is rooted in this enlarged, inlaid, engraved, and re-voiced “King of the Archtop.”

Epiphone, Stromberg, and D’Angelico immediately enlarged their patterns in response and the 18” archtop, once an early offering of the Gibson Co, was reintroduced. It’s hard to know exactly what the decisions were based on, but it seems that Gibson went back and forth between the two bracing designs, so although the early 400s were X braced, in 1940, Super 400s reverted to rail braces. I’ve looked and looked for more information on Gibson’s bracing designs, and there’s not much to find. It seems the Gibson company’s practices weren’t well documented, complicated by the fact that most archtop fans seem more interested in the style of tuner buttons used than they are in major construction specs. Fair enough, not all of us can be brace nerds. After all, if you’ve read this far, you’re on the team.

Gibson’s early X bracing design included two substantial transverse braces, seen here on Marty Lanham’s bench, as he expertly reassembled a very rare and cool flood-damaged, largely disassembled 1939 Super 400N for Tom Van Hoose. We see that the braces number four, not two, with the addition of two substantial transverse braces. The braces were left square in section, a big departure from Lloyd Loar’s elegant, carefully sculpted and tuned brace designs.

Opening his own shop in Manhattan devoted exclusively to archtop building in 1932, John D’Angelico used rail braces in his early guitars, which were originally faithful copies of Lloyd Loar's 16” Gibson L5. He built with both X and rail bracing patterns after WW2. There isn’t a record of how he braced each of his fine archtops through his career.

I don’t know of anyone who has seen one of Jimmy D’Aquisto’s guitars with rail bracing, so at least for now I think his guitars were all X braced.

From Charles and Elmer Stromberg’s Boston shop, this early period pressed top dates from circa 1930. The numerous braces were tasked with the job of reinforcing and holding the arch of the pressed top in the same manner as the early Martin C-1’s. Pressing the arched shape of the top was a cost saving method, deforming a thin piece of spruce with moisture and heat, rather than carving it from a thick board in the usual manner. Lots of folks tried to make good archtop guitars by this pressing/bending/torturing method, and likely are still trying, as Martin, Harmony, Regal, Premier, and Kay did, but at least in my opinion, none succeeded.

Around 1940, Elmer Stromberg switched from pressing to carving the tops and introduced his massive Master 400 with a 19” wide lower bout. He developed a subtractive variant of the X brace, a single diagonal brace, running from the upper bout on the bass side to the lower bout on the treble side, so that only the treble side of the bridge was positioned over a brace. It is said that Freddie Green’s favorite guitar was a 17 3/8” Stromberg Deluxe with this unique mono bracing pattern. Pretty sure the Strombergs went from “wow, that’s a lot of braces” to “are you sure that one brace is gonna do it?” in search of more power and a bigger voice. Well done, comrades!

In my repair work, I noticed that Gibson archtops from 1930 and later were sometimes braced with what we call kerfed braces. Of course, “1930 and later” is easy to say now, but the reality of the terrible damage to life and commerce after the collapse of the economy in late 1929 is impossible for us to imagine. I’m certain that Gibson management was panicking like everyone else, struggling to find ways to reduce costs and survive. In fact, a whole host of wonderful guitar, mandolin, and banjo companies went under in the 30s, much to our cultural impoverishment.

Just like kerfed lining, the braces were deliberately weakened by a series of saw cuts that reduced their stiffness and made the brace compliant, relieving the builders from the job of fitting the braces at all! After this kerf - emasculated piece of spruce was twisted and crushed by clamps and glued to the top, the top of the brace was shot straight with a little hand plane, and a piece of veneer was glued on to restore some tensile strength of the brace. These braces were a joke, and, no surprise, sounded like it. I’m not sure how widespread this practice was, or how long it was employed, but I have seen quite a number of them with my own eyes.

The most disturbing example was the first one I came across, a 1930 L 5 which presented as a pristine, lovely guitar, but sounded muted and awful. It so happened that my customer had also brought a 1929 L5 that looked identical, but had been beautifully tuned by the Gibson artisans, and sounded splendid. A look inside with a mirror revealed smooth, beautiful top carving and delicate braces in the ’29, and in the ’30, apart from the hacked braces, unbelievably rough work inside the top, including crude flat spots, horrible coarse disk sander scratches, and puddles of hide glue, making the cheapest Kay guitar interior look like a masterpiece. This appalling practice was designed to save time (time is money) and was clearly a desperate move to keep the doors open during the depths of the depression. OK, I get it, times were awful, but it still hurts to see this unforgivable abdication of excellence. I have here in my shop a 1932 Gibson L 12 which is another example of this terrible cop out, and this otherwise nicely built, well preserved guitar sounds unimpressive and quiet. I promise you that this instrument, which the pundits claim will “drive a big band with its cutting power” is clearly not up to the task.

Here’s a photo of the aforementioned kerfed 1932 L 12 braces.

This guitar shows neater work and somewhat less drastic kerf depths than other examples, but I’ve never seen a kerfed braced guitar that showed any hint of brace carving or tuning.

Sadly, although Gibson miraculously survived the depression, never were they able to assemble an all-star team like they had in the 20s again, with the possible exception of the (default) nearly all female labor force during the WW2 years. Please get a copy of John Thomas’ “Kalamazoo Gals” for this incredible hidden chapter in Gibson’s history.

Most contemporary archtops are X braced because the X design seems to help the top to vibrate in a wholesome, musical way. By design, the X design adds stiffness in both diagonal directions, as well as in the longitudinal and cross grain directions. The X tends to help power up the low end, adding warmth, sustain, and evening out the response.

In the days before acoustic archtops morphed into a kind of electric guitar, the instrument replaced the banjo as a rhythm instrument in big and small dance bands and was valued for its ability to ”bark,” or ”punch,” when very heavily strung with high action and heartily struck with a pick.

Tenor guitars were designed for players crossing over from the 4-string banjo, and like them, usually tuned in 5ths. A more modern, "less tenor banjo sounding" instrument was called for, and the archtop beat out the other two contenders, the steel bodied resonator guitars, built by National and Dobro, and the Macaferri designs built by Selmer in Paris in the 30s and 40s.

Although the archtop succeeded in its role as a rhythm instrument in a jazz band, claims of the archtop’s legendary “cutting power” can be overblown. Count Basie said to his horn players, “If you can’t hear Freddy Green, you’re playing too loud!” Since the magnetic pickup changed everything, these legendary attributes have long been out of style in commercial music.

You can still buy a heavy set of strings, eg. .014” - .068” that were commonly used at standard pitch back in the day, but maybe not at your local music store, as they are used in very small numbers. Today, very few players use these heavy gauge strings that were stock on the early archtops. Even with the original “short” 24 3/4” scale employed by Gibson, string forces were massive. In my days as a repairman, I witnessed some career ending repetitive use injuries, potentially a tragic result of this kind of heavy setup. It turns out that most of our hands and wrists are just not built for applying the large forces required by them over the long haul.

The great Eddie Lang’s favorite string set was .015” - .075”, with a wound .018” for the B string! Lang was the influential, virtuosic innovator who played Gibson L-4s and L-5s, and is thought of as the father of jazz guitar.

The .012” - .053” phosphor bronze strings that I like best on my own 25.5” scale guitars apply a tensile load of around 165 pounds, while Eddie’s setup on the L-5’s 24.75” scale would have been 220 - 240.

Obviously, bracing requirements for this kind of string force are on another level, and it is said Gibson had to replace Lang’s guitars when they became distorted from the string forces.

Currently, there seems to be broad agreement that X bracing helps make better sounding guitars. Most of us don’t mourn the near passing of the rail braced archtop, although a few are still braced this way today, and of course, builders continually experiment with new bracing strategies (just try and stop us).

It seems to me that the keys to power and tone lie in the flexibility and responsiveness of the top no matter what style braces are used. After all, Gibson made some stunning sounding rail-braced 16” L5s from 1923 - 1929, thanks in good part to Lloyd Loar’s experiments and guidance. These were light guitars, usually around 4 1/2 pounds, and the braces are lovely, delicate little things, having been installed, shaped, and tuned by master craftsmen who were given the time to do their best work.

It is reported that one of the very first L5 prototypes is inscribed in pencil by Lloyd Loar, “make the braces a little thinner,” as an instruction to one of his assistant “A team” builders. Master Loar wasn’t a builder himself, but a virtuoso performer and acoustic researcher. He ran a crack development team that followed his lead and learned to apply his plate and brace tuning methods.

My observation is that many archtop guitars are wildly over-braced, the result of which is a needlessly low powered instrument with a weak bass response. To produce low frequencies, the top must be light, supple, and easily driven by our tiny little wire strings. After all, we have only a fingertip or a plastic pick to energize the strings, which aren’t very massive, and can deliver only a relatively small amount of energy to the top, no matter how we strike them.

My thinking is that the brace’s main job is to unify the behavior of the top, especially at low frequencies, not so much to prop it up. The low E on the guitar has a wavelength of 13’ 8” (419cm), and the guitar top is less than 2’ (61cm) long. We can imagine that the guitar body needs all the help it can get to develop this massive wave, so I try everything I can think of to make it easy for the low notes to start and sustain.

The job of brace fitting is the careful shaping of a stick of spruce to perfectly fit the complex, twisting surface of the top. The two parts need to meet closely, ideally touching each other everywhere they can, requiring only the slightest pressure to bring the surfaces together. It’s crucial that they are carefully fitted and solidly glued so that they can be relied upon to never come undone. One of the most miserable jobs in the repair shop is the re-gluing of a loose or cracked brace, working through two tiny f-holes. Ugh.

Tuning is the process of slowly and carefully shaving the brace to reduce its stiffness so that the braces and the top can cooperate and become optimally energetic while retaining enough strength to resist permanent deformation. It’s easy to chicken out and leave the braces and the top thickness “a little big, just to make sure,” but this is the road to mediocrity, not excellence. It’s difficult to know just when to stop removing material, and without the willingness to experiment and risk failure, probably impossible. Because the stiffness of a material changes with the cube of the thickness, tiny reductions in thickness have profound effects on the stiffness, and therefore the responsiveness of the top. Patience and sensitivity are required to achieve optimum results. In my opinion, this is what separates the stars from the understudies, as knowing exactly when to stop cutting makes such a huge difference in the final voice of the guitar. This process is critical.

The traditional fitting methods, centuries old and still employed, involve the use of planes, spokeshaves, gouges, scrapers, chalk and hide glue. This is not an easy job for a beginner. It requires judgment, patience, skill, and practice to succeed. Builders of violin family instruments have developed a bag of tricks to precisely, repeatably locate the brace during marking and fitting, often using chalk or carbon paper as a means to identify the places that are in contact as fitting proceeds.

Ultimately, the question comes down to defining the brace’s job. I believe that the braces can help make the top behave in a more energetic and wholesome way by adding strength in the cross- grain and diagonal directions. Add too much strength, though, and you immobilize the top, making it too stiff to respond to the strings.

My braces are extremely small and light, tapering gradually to zero thickness at the ends, almost like variable thickness fiber tape. Before gluing, I make sure that the mating surfaces are perfect and that they fit together tightly with just a fingertip’s pressure.

You might say I’m with both Orville and Lloyd on this, as Orville thought braces weren’t needed, but used them anyway, and Lloyd says, make ‘em thinner!

Here, I’ll show the methods I use to accomplish this demanding and important task in my own work. I have devised my own positioning fixtures, precise marking tools and methods, and some tomfoolery that have taken all the pain out of this job for me and, I hope, maybe for you too!

As I have been obsessed with archtop guitars my whole life, the analysis and historical view I’ve presented here is the current version of my own evolving perspective. If you think that I’m mistaken, have missed an important facet of the story, or feel that you have some useful information to contribute, please contact me, and we can chew the fat. I’m always grateful for new information and editing input!

I’ve been frustrated with how little is known about Orville’s development work and would be grateful for any insights or additional information about his hand made instruments. If you happen to own one of Orville’s creations, I would be especially happy to meet you, and gain some insight into his remarkable work. I’m eager to see if we can locate, measure and X-ray other instruments made by Orville, the primordial ooze of archtop guitars. His was, as I see it, daring and original design work from a powerful guy who put his money where his mouth was.

Finally, apart from credit for photos, I’d like to thank some comrades who have helped me get this introduction to bracing into focus with their experience and expertise. In alphabetical order, then: Dick Boak, Walter Carter, Chris Mirabella, John Monteleone, John Thomas, and Joe Vinikow.