Instructions for building the top plate of a modern flattop guitar. The instrument used in the example photos is a classical guitar but the procedure is the same for the steel string guitar as well. Power tools (planer, jointer) are used in the examples but hand tools can be substituted as desired.
Initially appeared: January 19, 2010
Last updated: September 11, 2018
After buying or selecting from your stock the wood you'll use to make the top, the first real step in the process of building the top plate is assessing the wood. In the best case, we do this to use the wood so it looks the best it can look in the finished instrument. But we also want to critically assess the wood we intend to use at this time to be sure it is really suitable to be used in an instrument. Lutherie wood is expensive, but it is still cheap relative to the labor that goes into making an instrument. So, before we start work we want to make absolutely sure that the piece of wood we intend to use is not defective.
Hobbyists will usually buy wood specifically for a project. I tend to buy most of my wood for stock, so it usually is sitting around the shop for a while before I use it. This being the case I like to go through these steps of examining the wood as soon as I get it. This way if it is defective I can return it easily. If I keep it, I know that the wood I have in stock is sound and ready to use.
In general, wood for an instrument top comes from the supplier as two bookmatched pieces about 0.25" thick and long and wide enough to make an instrument top. Some suppliers deliver top wood planed - others plane the surfaces of top wood hit-or-miss (also called skip planing), which means they pass it through the planer once per side, which rarely leaves the piece perfectly smooth over its entire surface. Still other suppliers deliver top wood rough cut. If the top wood you have is not planed smooth on both sides of both pieces, that should be done now. You don't want to take too much material off at this point, just enough so you can assess the wood. This can be tricky, as top pieces tend to come pretty thin these days, so keep in mind while you are doing this that ultimately the top will be a bit less than 0.125" thick. If you can plane the pieces smooth and still have 0.16" or a bit less at this point, that would be good. Great care should be taken to avoid planing into the runout on the top pieces. Doing so will tend to pull big chunks of wood up, and you really don't want to do this with pieces of wood that are pretty thin and pretty close to their ultimate thickness to begin with.
You can do the planing with a planer or a plane. If what you have is a thickness sander I suggest that you take a few passes on each side and then finish up with a card scraper or cabinet scraper. You'd be amazed at the things you can see when the surface is finished with an edge tool.
It is good to have a nice straight ripped edge on what will be the inside seam of the finished top, and also good to have a nice clean cut at the ends of both pieces so you can assess the end grain. Here again, lutherie suppliers don't often give you a lot of extra length and width to play with these days, so be careful when making these cuts not to end up with a piece that is too small for the instrument.
Once the top pieces are ripped and planed they can be examined for checks and other cracks. If you hold each piece in the air by tightly gripping just one corner and then rap on it sharply on the center of the piece with your knuckle, you should hear a solid "thwack" sound. If you hear any buzzing or if the thwack ends with a buzz, then there is probably a crack somewhere. I like to pick up each piece between my hands and flex it slightly across the grain. Doing this with your hands near the top of the piece and then near the bottom should turn up any cracks. If you find a crack you can either glue it or reject the top. I will generally glue a small crack if it follows a grain line, but will reject a top if it has more than one small crack or if any of the cracks cross grains lines. The latter cannot be fixed invisibly.
This is a good place to point out that reputable lutherie wood suppliers should replace tops with cracks or other defects that are not acceptable in the grade of the wood you bought. I inspect wood as carefully as I can when I get it, but there are still some times that defects turn up that you didn't catch up front. Lutherie wood is expensive because it is, by definition, suitable for lutherie use, so never feel you need to get stuck with a defective piece of wood.
If there are no obvious cracks then we can go on to assessing the top wood for aesthetics. Position the two top pieces as they would appear in the finished instrument. The pieces are bookmatched, so we basically separate them like opening a book. The grain of each piece will be wider at one side than the other - keep the wide grain on the outside, that is, open the "book" so the narrow grain of one piece touches the narrow grain of the other. Now take a good look at the top under good light.
We're looking for two things - oddities in the grain, and oddities in the overall color. Color oddities are pretty basic. The higher the grade of wood you bought, the more even the piece should be in color. But even low grade lutherie wood usually doesn't have abrupt color changes where they are most obvious, right at the center seam:
This would make for a pretty bad looking top, but fortunately the dark band is only found on the very surface we are looking at in the picture. If the whole thing is turned over it looks fine on the other side. As you find flaws like this it is a good idea to mark them with a pencil. It will make it easier to make decisions about which side of the top to use as the outside surface if you can clearly see all the flaws.
Other flaws to look out for are things like pitch pockets.
These usually run pretty deep so there is really no hope of planing them away. If you have one or more that fall in the area where the instrument top will be then the top blank should be rejected.
The remaining types of flaws are all perturbations of the grain. In the higher grades of wood the grain tends to be straighter and more even, with the grain lines closer together. Lower grade wood has more irregularity in color and in the grain. Some types of grain perturbation are desirable, at least by some people. The grain pattern called bearclaw, which looks like the wood has been deeply scratched by the claws of a bear is one of these:
I like the look of this myself, but some folks don't want to know about it. The irregularity of the grain is usually very shallow, so sometimes you can plane the bearclaw away. If you intend to do this you should take a very careful look at the back side of the plate to see if you can find evidence of the bearclaw figure. If so, it is all the way through the plate and planing it off is not going to happen.
One grain flaw which really bugs me is knot shadows. These are places where the grain is bent locally around a knot in the wood. The actual knot is not in the piece of wood you have - it was in some previous slice or slices. But you can see the place where the grain in your piece bends around the knot:
The problem with knot shadows is they stick out like sore thumbs in the finished instrument because they reflect the light differently. If there is a knot shadow within the outline of the instrument's top I reject the blank.
At this point you should have a good idea where all the flaws are on the two pieces of top wood and a good idea of how deep they run through the pieces, too. If you haven't rejected the top outright at this point, it is time to figure out which surface will be the outside of the top plate. Placing the body mold or the completed rib garland on top of the two plate pieces will give you a good idea of how things will look in the completed instrument top. Try both sides, and try rotating the blank 180 degrees, too. If the pieces you have are long enough you can also slide the pieces up and down a bit. The point of all this is to find the best looking surface of the blank. Once you've found it you can pencil or chalk the rough outline of your instrument on the blank. But be aware that if the blank will be planed some more on this side your marks will be planed off as well.
Since I examine top wood in this way as I receive it and then store it away for later use, it is very possible that I won't actually use a set for years after I've first examined it. If you are not going to use the wood right away it is a good idea to write some information about the set right on it. One of the upper corners is a good place to write as it will be outside of the instrument outline. I generally write the date, the species of wood, the grade, the name of the supplier it came from, and the amount paid for the set. This information ends up being very useful in the future.
If it has been some time since you did the original examination and assessment of the top pieces it is a good idea to do this again now to reacquaint yourself with the wood. If the top pieces are thick it is a good idea to reduce their thickness now, before jointing. My planer will plane down to 0.125" thick, so I tend to plane to that thickness before jointing. Don't plane down to the plate's final thickness as there is still the possibility that the joint will end up not quite flush, which would require further planing.
Once the halves are at the desired thickness they can be jointed for the center seam. Needless to say this joint has to be perfect because it is in plain sight, in light colored wood, right on the front of the instrument. I generally use a well set up jointer to do this operation. The two pieces are folded together and jointed at the same time:
You want to keep even pressure on the pieces and run them over the cutter at a nice even speed. I set the jointer for a very shallow cut and I listen to the sound it makes while the pieces are being cut. It should make a very even sound for the entire length of the joint, indicating that the entire length of the cut has taken off some wood.
When you think you've got a nice joint, the halves are opened up like a book on the bench and then picked up in the hands while holding the jointed edges together. The joint is candled, that is, held over a bright light so you can assess the closeness of the joint.
If you can see light anywhere through the joint it will be necessary to joint the edges again. I find that my best efforts to set up the jointer with a straight edge are never good enough for this operation. So I set up the jointer as best I can with the straight edge, then run a dummy "top" over the jointer and candle the joint. If the joint gaps in the middle, I raise the outfeed table a hair. If the joint gaps at the ends, I lower the outfeed table a hair. It usually takes a few tries to home in on it. But once it is set, I rarely have to take more than one clean pass to joint the top halves.
The top halves can also be jointed using a hand plane and a shooting board. In this operation both halves are jointed at the same time using a plane that is on its side.
In the picture I'm using a #5 plane, but I generally use a #7, which unfortunately is just too long to be used for the picture. The shooting board is just a flat board with an end stop and a raised platform on it. The platform raises the top halves up enough so they can be touched by the plane blade. Mine also has a holding bar to keep the top pieces in place and an edge that the base of the plane runs against. That edge is made flat and straight using an iron level covered with self-stick sandpaper. Some folks joint the top halves using a level and sandpaper. This method does not likely result in as strong a joint, but on the other hand I don't know of anyone that uses that method that complains that their top joints chronically open up.
The top halves are glued together on a gluing board. Any flat board that is slightly bigger than the top blank can be used. You have to make the board so glue seeping from the joint doesn't glue the top to the gluing board. You can simply place a piece of wax paper on the board, or you can wax the board, or you can use some kind of board that glue doesn't stick to. For my gluing board I use a sheet of Melamine covered particle board.
Before joining the halves, the outside edges are ripped off square to the jointed edges on the table saw. Leave the pieces as wide as you can, that is, only take off as much wood as you need to make the outside edges parallel to the jointed edges. This way, if you screw up the join, you can always rip the pieces apart and try jointing and joining again (yes, I have needed to do this, more than once).
The setup for gluing and clamping the top halves is pretty straight forward. One picture is worth 1000 words, and here is the picture:
A flat board with a straight edge is placed on either side of the top and clamped in place. Space is left on one side to place pairs of small wedges (on the right side in the picture) between the board and the edge of the top. A bead of glue is run down one edge of the joint and then the top is assembled on the gluing board as shown. The wedges are lightly tapped into place. Then the joint is pressed firmly down to the gluing board - I do this last step with a rag at the same time as I am wiping the glue squeeze out from the joint. Then some weight(s) is placed on top of the joint itself to keep it from popping up. In the picture I'm using the #7 plane for this purpose, and I have a piece of wax paper between the plane and the joint. As usual with gluing operations, it is always a good idea to do a dry run first before applying the glue. I like to leave the top and bottom edges of the two plate halves slightly out of line. This makes it easier to find the centerline during future operations.
Now the top can be thinned to close to final thickness, which will be somewhere in the vicinity of 0.1" for most instruments if it it spruce and about 0.12" if it is cedar. Get this info from the plan you are using. In my shop I use a drum thickness sander to do this. Since the sander leaves noticeable grooves in the wood even with 80 grit paper I try to only sand the side of the top that will be inside the instrument. The outside surface will always have some hardened glue at the seam and one side may end up raised a bit at the seam, too. Imperfections like these can be quickly dealt with using a card or cabinet scraper before beginning the thinning process. After the top is thinned if I've obliterated my pencil markings I will write on the outside surface in pencil to indicate which is the outside face.
The next step is to mark the outline of the instrument top onto the blank. Lay the blank outside face up on the bench and then lay the mold on top, aligning the centerlines of the mold and the blank. It if often difficult to see the center seam of the blank, particularly if you've done a good jointing job, so if necessary mark the centerline with pencil now. Move the mold as necessary to exclude any imperfections in the wood from within the outline. Then mark the outline on the blank with a pencil.
Since most of the work on the top will be done on the inside surface I like to mark the outline on that surface as well. On the outside surface, measure down from the top edge of the blank to the top of the outline. Flip the blank over and place a mark on the inside surface at that distance from the top edge. Then position the mold over the blank as before but this time also aligned with that top edge of the outline mark. Now the outline can be traced onto the inside of the blank with pencil.
If the instrument you are building has a cutaway (or if the outline is otherwise asymmetrical about the centerline) be sure the inside and outside drawings are mirror images of each other.
As mentioned many places on this site, I am a big believer is writing information right on the instrument. These notes help keep the screw-ups to a minimum (as also mentioned many places on this site, I screw up a lot). If you haven't already done so, writing "outside" on the outside in pencil wouldn't hurt. I don't like to write on the inside since it is not likely I'm going to sand it, but if you do want to write a note on the inside a good place to do it is at the top or bottom edge, in an area that will be covered up by one of the blocks.
There are three general classes of soundhole decoration: binding the soundhole, purfling rings, and the tiled rosette. Soundhole binding is a simple decoration that goes well with some modern guitar designs, and it can be used in combination with other decoration as well. See the page on binding the soundhole on this site for instructions how to do this. It is traditional for steel string guitars to decorate the soundhole with concentric purfling rings. In this class of decoration each concentric ring around the soundhole contains some purfling lines, and the main ring sometimes includes a line of pearl inlay as well. I don't have instructions for doing this on the site (yet) but it is easy enough to figure out how to do it based on the instructions for the next general class of soundhole decoration, the tiled rosette. Classical guitars are traditionally decorated with a single ring that includes an area of wood mosaic tiles bordered by purfling lines on both sides. See the page on making the tiled rosette on this site for instructions how to do this.
I like to keep the plate blank rectangular while doing the soundhole inlay, as it makes it easier to butt the plate up against a stop or bench hook for planing and scraping. Once these operations are done, the outline of the plate can be cut out on the band saw. Leave some space - don't cut too close to the line, as the final outline will result from fitting the top to the ribs.
Cut out the outline so that you can retain the full width of the top and bottom cut off pieces, like this:
These can be used to make the reinforcement strips for the center seam when you make the back plate.
After the soundhole is cut out, the entire area is very delicate and so I try to get the upper bars and soundhole reinforcement patches glued on as soon as possible.
The braces and patches for the top are generally made out of quarter sawed spruce, although steel string guitars will usually use hardwood for the bridge patch, because this piece bears compression from the string end balls. What we need to do first is to take inventory of all the top braces and patches we'll need and then figure out the dimensions of the rough rectangular blanks needed to make those braces. You'll generally find that there are only two or three thicknesses of braces required and this makes this task a bit easier.
The top for the classical guitar I'm building in the pictures makes use of a very common classical guitar bracing pattern called a seven fan bracing pattern. The braces look like this:
A little vocabulary is in order before we start in on the wood work, just so the explanations make some sense. The topmost horizontal brace is called the upper transverse bar (or brace). It is also called the upper harmonic bar, but I eschew the use of the word harmonic when describing this brace because it makes it sound like the dimensions of this brace are somehow related to the harmonics of the tone of the finished instrument. Although the dimensions of each and every part of an instrument contribute in some way to the sound of the instrument, this brace is located in an area of the top that doesn't vibrate much and therefore doesn't contribute much to the sound of the instrument. The purpose of this brace is as a beam to support the end of the fingerboard, and as such it is usually quite thick and quite high.
Below the soundhole is the lower transverse bar (or brace), also called the lower harmonic bar. Between the transverse bars on both sides of the soundhole are located thin reinforcement patches. These provide strength to the thin area of the top below the rosette.
Below the lower transverse bar are the seven fan braces, and below those are the two cutoff bars. In this instrument the two transverse braces are the same thickness, the fan braces and cutoff bars are the same thickness, and all of the patches are the same thickness.
After the list of all the needed stock pieces is made, a suitably big piece of brace stock is selected and then cut up into sticks. The traditional way to do this is to split off the sticks, leaving them wide enough so they can be planed to proper width in a subsequent operation.
The advantage to splitting the pieces is that there will be no runout in the braces, as splitting exactly follows the grain. The disadvantage is that splitting and planing is time consuming and really offers no structural advantage in the finished brace. No factory splits bracewood and not all hand builders split bracewood either. The alternative to splitting is to simply rip the pieces off on the table saw. This is a whole lot quicker because the pieces can be sawn to width - no subsequent planing is necessary. If you want to keep the pieces close to quarter sawn, adjust the blade angle to match the angle of the end grain.
Note that in the picture the blade guard has not been removed for clarity.
Not all luthiers bother to angle the blade, and the resulting braces will not necessarily end up quartered. Here is some information that may help you decide how you want to cut the brace blanks. These pieces were traditionally split and planed, but that tradition was established before table saws were available. Back then, splitting and planing were more time efficient than ripping with a hand saw and then planing. Over the years some lutherie lore has evolved which maintains that the brace blanks must be split and planed so the braces end up perfectly quartered, which is necessary for stiffness and stability. In fact, there is solid evidence that wood is no stiffer when quartered, and stability is hardly an issue with components this small that are glued down along their entire length. This all argues for just ripping the bracewood on the table saw with the blade set straight up.
But (there's always a but) braces are far easier to carve when they are quartered and don't have any runout. Not too much of an issue if you intend to machine your braces to shape or shape them on the belt sander, but something you may want to consider if you intend to carve them with plane or chisel, especially if you are not yet skilled at brace carving. My personal preference is to cut brace blanks on the table saw with the blade angled, but I am not adverse to ripping with the blade straight up if the chunk of wood I have is on the thin side or if I intend to shape the braces before they are glued to the top. For first timers that intend to carve braces with plane and chisel, I heartily recommend that you split and plane your brace stock. Handling a paring chisel takes quite a bit of practice to begin with, and having to pare from all different directions and angles to deal with grain irregularities makes things a whole lot more frustrating.
After you've sawed and possibly planed some pieces to width, they can be sawed and planed to height. The pieces for the big transverse braces can just be planed to close to the height of the finished braces. The finger braces and fan braces are often shallow enough so that you can get two or more blanks out of a single stick. In this case I'll rip the sticks on the band saw and then run them through the planer to plane them to near the finished height of the braces.
At this point you have a bunch of long blanks with the rectangular dimensions of your braces. I generally cut these to length as they are needed, but the finger braces can usually be chopped off to finished length at this point. One reason not to do this now is that the finger braces can often be made from the off cuts from longer braces.
The material for the patches must also be prepared. Again, quarter sawn stock is preferred, and is planed to proper thickness. Then the individual pieces can be cut out.
Shown in the picture are the bridge patch and soundhole reinforcement patches for a traditional style classical guitar.
This process is pretty straight forward. In general, all brace location measurements should be referenced from a single point. The point on the centerline that is the neck end of the body is the one I usually use. As you take measurements from your plan, you can mark the locations of each brace on the underside of the top in light pencil. A carpenter's framing square is very useful for this process. It is big enough so you can reference the centerline anywhere on the top, plus it is heavy enough to keep the top flat on the bench.
I generally only mark the locations of the ends of the braces, because I don't want to spend a lot of time either erasing those pencil lines or covering them up. The problem with only marking the brace ends is that if you are not really familiar with the bracing pattern you are using, it can be easy to get confused about where the braces actually go when it comes time to glue them down. You do get better at this with time and practice, but I would recommend that first timers may want to more fully and unambiguously pencil in the brace locations.
It is considered good workmanship for no pencil lines to appear anywhere on the inside of the instrument when it is done. This is a matter of social convention really, and I am not all that sanguine about it. Antonio de Torres is generally considered to be the greatest classical guitar maker ever, and the insides of his instruments are full of pencil lines, as are those of many early builders. The attitude of most of our luthier ancestors seems to have been that there was no sense in prettying up the inside of the instrument, since no one can see it anyway. This attitude changed over time, and I suspect that it was the popularity of factory made instruments that changed things. In general, factories will locate braces during assembly using a template, and so they just don't make any pencil lines because they don't need them.
Here's a little tip for keeping the visible pencil lines to a minimum. When you mark the position of a brace, do it a bit undersized, so that when you glue the brace down the brace will completely cover its positioning pencil lines. Any lines that remain can be cleaned up by scraping and sanding after the top is otherwise ready to be glued to the ribs.
The main thing to know about modern guitar construction is that the plates are domed. They hold their domed shape because the bottoms of the braces are domed to the correct arch, and when the braces are glued to the plate it (the plate) is placed into a dished workboard. Clamping pressure bends the thin plate to conform to the shape of the dish and when the glue dries on the braces the dish stays domed.
So the first step in gluing on the braces and patches is to cut them to approximate length (keep them a little long) and then dome the bottoms of all the braces. You can make a brace arching jig to do this, or you can scribe the curve of the dish onto the brace and then plane or sand the bottom of the brace to shape, but the typical radius of dome of the top is so small that you can easily do it just by sanding. Here is a brace sitting on the sandpaper-covered dished work board:
You can see that the flat bottom really needs just a bit of sanding to dome it to the radius of the board. It is a good idea to mark up the bottom of the brace with pencil before sanding, so you'll know when the job is completely done.
Sand the bottom by holding the brace with two hands and scrubbing it back and forth over the dish.
Don't push down on the middle of the brace while sanding. That will spring the middle of the brace down and the bottom will not be sanded to the radius of the dish. This is a little tricky to do with very thin and shallow braces, but if you hold the brace just at the ends while sanding it works out fine. Don't lean the brace over as you sand either.
The thin patches don't get their bottoms sanded like this, but if the bracing for your instrument has any thick (over about 0.125") patches then they should have their bottoms domed, too.
After all the brace bottoms are domed it is time to glue them on to the top plate, assuming fo course that you intend to profile (shape) the braces after they are glued on. This is the way we'll do it here. I like to use the go bar deck for this job, but clamps or a vacuum clamping frame can be used as well. If you intend to use clamps, keep in mind that you need to have one arm of each clamp under the dished workboard, so the collection of clamps you'll need will include a number of long ones. I like to put a piece of heavy plastic drop cloth between the dished workboard and the plate to keep the image of the heavy sandpaper grit from being impressed into the top.
The order in which you glue down the braces is usually not critical, but I generally start with the patches. Doing so lets me get the patches that reinforce the soundhole rosette in as soon as possible - that area of the plate at this point is extremely delicate, so I want to get the reinforcement on quickly to avoid a costly accident. And I like to glue down the bridge patch (assuming the bracing pattern has one) because its location is critical and the bridge patch usually serves to align other braces.
In the pictures that follow I am building a fairly standard Hauser style classical guitar, and that dictates the order I am putting the braces down to some extent. Generally speaking, it is often a good idea to put some braces down, carve them, then glue down others that would get in the way of carving those first ones. The pictures show a lot of basic brace gluing technique that is applicable to most bracing patterns. The first brace I glue down is the upper transverse brace:
A light coat of glue is applied to the bottom of the brace and it is dropped into position. When the glue grabs, the clamps or go bars are applied. Here I am using fiberglass go bars that exert a lot of pressure and leave dents in the spruce. This brace has been cut to height already so I'm using a caul to prevent the dents in the top of the brace. If you look closely at the picture you can see some of the rest of the layout marks for the other braces.
When the clamps are applied you'll get some glue squeeze out around the brace. You can wipe this up, but if you do you will smear it into the spruce and it will take some doing to clean it up so it is not visible later. You may not care about this, as it is on the inside of the guitar after all. But the generally accepted modern hand builder's method of dealing with the squeeze out is to wait 20 minutes or so until the glue gets leathery and then chisel it away using a long chisel. I use a special bent glue clearing chisel designed by the late Richard Schneider. It doesn't take a lot of work to clear the glue - you just run the chisel up against the brace on one side, then the other. If the glue is still wet, wait a few more minutes and try again. Don't want to spend the money for a special chisel just to clear glue squeeze out? Clear the glue with a plastic soda straw clipped at an angle. Do this before the glue gets too hard.
I glue the top transverse bar first on this instrument because the two sound hole rosette reinforcement strips butt up against it, and then the lower transverse bar butts up against them. So in the next brace gluing step, I'll add all those, plus the bridge patch. Note that you may want to leave the lower transverse bar off for now, because it will get in the way when you carve the fan braces. This is of course not an issue if your instrument doesn't have fan braces. But I am gluing this one down now on this instrument because I want to be sure the rosette is supported. Again, note the use of cauls. The bridge patch caul is just a bit smaller in dimension than the bridge patch itself.
On this instrument, I glue down the fan braces next. There are seven of them, and five of these have to be notched to fit over the bridge patch. A fan is put into position and then it is marked on both sides with the front and back edges of the bridge plate. These lines are connected on the bottom of the brace, then a razor saw is used to cut shallow cuts at the ends of the notch. Cut a little inboard of the lines so you can make a nice tight fit later. Then the notch is cut out with a chisel and/or knife. The bridge patch is so shallow on the Hauser that I just use a knife.
The idea is to chisel and test fit until you end up with a nice tight fit and the brace is in contact with both the surface of the bridge patch and the top plate. After the notch is cut, the fan brace can be cut to final length. Then it is glued down. Cauls are needed to distribute the clamping pressure with these slender and shallow braces. I usually glue all the fans down at the same time, but if you are going to do any glue clearing do keep in mind that you'll need to do it around the clamps, so plan the sequence in which you glue things down accordingly.
This instrument has two more braces near the tail block called cutoff bars, but I usually glue these down after the fan braces are carved.
Again, I am working on a Hauser style classical guitar here, but the brace carving techniques are generally applicable to other instruments. One thing I want to point out is that braces need not be carved after they are glued down. A lot of hand builders and most factories shape the braces before they are glued down. But carving braces in situ is the most common way one-at-a-time hand builders do it.
Braces are usually carved first to some longitudinal profile along their entire length. Your plan will show an end view of the profile of each brace. There are three basic profile styles: rounded, triangular, and "parabolic". Rounded braces just have their tops rounded over, so the profile ends up with straight sides and a rounded over top. The profile of triangular braces is, well, triangular, with a wide base and a narrow peak. This profile doesn't necessarily have a sharp point on top, but the basic shape is more like a triangle than anything else. "Parabolic" braces are shaped more or less like parabolas, with a wide base and thinner rounded over top. I have the word "parabolic" in quotes because I want to be sure you understand that this shape is only approximately that of a parabola and is not is any way derived by a formula.
Every luthier has their own set of tools used for brace carving. I use a small flat-bottomed violin maker's finger plane, a paring chisel, a knife, and a larger palm plane (Stanley #100 type). A small palm skew chisel is also useful, as is a small sanding block with an angled side (more about this later). Here's a picture of the tools I use:
The planes are used preferentially, because they are far easier to control than the chisel is. But the chisel is almost always necessary for a couple of reasons. The first is that you can not plane the sides of a brace right down near where it joins the top plate with a regular plane (note that some luthiers use a rabbiting plane to do this). The second reason is that you will invariably run into situations where you will need to cut from a certain direction to avoid tear out and you won't be able to get the plane in there to make the cut. The chisel and/or knife will be the only tools that will allow your to make the cut. This is much more of an issue if your brace stock is not perfectly quartered and has runout.
The transverse bars are the simplest to carve because they are big and access to the ends is not blocked by anything. I shape by eye only, always starting with a plane if I can help it. The top edges are faceted first.
Note the masking tape on the plate around the base of the brace. This is to keep me from gouging up the plate while carving. Sometimes this is necessary and sometimes not. Masking tape and thin cardboard work well to protect the soft plate. Note that even repeated passes with the plane can wear grooves in the soft top wood with the edge of the plane.
Here the fans braces get the same treatment, only with a different plane.
As mentioned, you can't get right down to the bottom edge using a conventional plane.
To do that, you'll need either a small rabbeting plane like a #90 or you'll have to use the paring chisel. The paring chisel is long and is handled a lot like a pool stick. You push it with one hand while guiding the cut with your other hand, like you were making a bridge to support the pool cue for a shot. With both planing and chiseling, if you find the blade is gouging out big hunks of wood then you are cutting into the runout, so make the cut from the other direction.
On the classical fan braces, the neck ends are close to the lower transverse brace, so I can't get either the plane or the chisel in close enough to start a cut at that end. here I have to resort to the small skew chisel or the knife.
After the profiles of the braces are cut everything can be cleaned up and smoothed by sanding. I find a small sanding block with one angled side makes it easy to sand the sides of the triangular braces.
After the braces are profiled longitudinally their ends can be carved. This is called ramping the ends. It the ramps are long, they can be started with the plane.
But if they are short they have to be done completely using the paring chisel. For those braces that ramp down to nothing, the ends have to be finished with the paring chisel in any case.
There are a few variations on the straight ramp described above. The first is the curved or hollow ramp. As the name implies, rather than ramping down in a straight line, this style of ramp kind of curves down. You pretty much can't cut one of these with a flat-bottomed plane. But a small plane with a sole arched front-to-back can be used to good effect, as can a longitudinally curved sole spoke shave. It is also possible to shave out a hollow ramp with the paring chisel by digging in deeper at the center of the cut than at the start and end of the cut. Sanding drums mounted on a drill or flexible shaft tool can also make fast work of these cuts.
The other variation on the ramp that is worth mentioning here is the scallop. Scalloped braces have a hollow cut in the center of the length of the brace. In terms of how the work is sequenced, cutting a scallop it exactly the same as cutting two hollow ramps toward each other in the center of the brace.
Once cut, the ramps can be finished up with sandpaper on a small block. This is the final step in carving the braces.
Cleaning up the inside of the top is the last step before the top plate is finished and ready to attach to the rib garland. This generally involves scraping and sanding the inside surface to whatever level of cleanliness you desire. Any remaining pencil marks or glue squeeze out can be removed at this time. Some folks leave the inside of the top beautifully smooth, while others consider any serious effort on an unseen part of the instrument to be superfluous. Even if you don't want to spend a lot of time on this step, it is probably a wise idea to at least clean up the parts you will be able to see through the soundhole once the instrument is assembled.