MIMF

Maple and mahogany can be quite similar in properties. The first archtop I made had mahogany B&S, and so far as I know it's still going strong after 30+ years. The way you make it has far more bearing on the sound you get than the material, so long as that's 'reasonable'.

I usually do those with an in-cantle gouge: the bevel in on the inside of the curve rather than the outside. I got one years ago at a yard sale. It has an offset handle, so that you can push it while making the cut. I surmise that it was made as a pattern makers tool, used to form the fillets on ins...

Some old Martins with 'bar' bridges had plates that were exactly the same size as the bridge. The combination of the plate and the bridge ending along the same line made a huge stress riser: all the bending was at that point. I repaired a couple of 0-15s with mahogany tops that broke right at the fr...

I've bound F-holes on archtops by super gluing on strips of veneer. It's about the only way I can think of for binding an irregular hole. For round holes I've made tapered plugs that can be used themselves if you drill a hole through them, or as forms to laminate veneers. The taper allows you to san...

You could taper the front and back edges down: the only part that has to be full thickness is where the ball ends of the strings are. I like to have both the front and back edges of the bridge plate out past the edges of the bridge, but tapered out as thin as I can get them to minimize stress risers...

The X braces seem low to me: mine usually end up around 9/16" at the high point. 7/16" wide is pretty beefy, but width isn't as good as height for stiffness. The stiffness of a brace goes as the width and the cube of the height.

Ends of braces between the neck and the bridge need to have some height, to counter the down force os the bridge torque. Those need to be supported at the ends. Below the bridge the braces can taper out to nothing if you want, but if they don't, for whatever reason, those will neen to be supported a...

Shades of the 'Vin Fizz Special'. That was the first airplane that made it across the country in less than a month: 32 crashes in 29 days, iirc. When it landed in California the pilot had a broken arm, and the only two pieces of the original left were the gas cap and one wing strut. You've got to dr...

I'm going to trot out one of my favorite quotes from British designer and wood worker David Pye: " Where the problem is old, the old solutions will nearly always be best (unless a new technique has been introduced) because it is inconceivable that all of the designers of ten or twenty generatio...

If you use Cladni patterns to look at the way the assembled guitar vibrates it's pretty easy to show what happens. The loudspeaker-like 'main top' resonant mode is the most effective radiator of sound on the guitar, because is has most of the lower bout moving in the same direction at any given time...

Making the sides heavier can alter the sound; it tends to 'keep the sound in the top', and can increase the power. Gore covers this in his book.

Peter Wilcox wrote: "...the center of the x is placed too far toward the tail, toward the most resonant part of the top..." There are a number of different ways to profile the braces, and they produce different timbres. One and of the continuum is 'tapered' bracing, which is tallest around...

II use an arched UTB, but that's unusual: I think it may help stabilize things in the long run, but who's to say? The neck set ends up with a bit of an over stand, and there's a wedge between the fingerboard and the top. I prefer to fit the wedge rather then removing material from the end of the fin...

I've always use the same radius on my 12s and on the 6s; 25'. Don't over build. I've found that using the same bracing pattern, making the top of a 12 about 25% thicker than I would for the same wood on a 6, and making the braces 25% taller and a little wider, ends up being plenty stiff enough. Sinc...

It wasn't clear that you were talking about the top bracing. Did you arch the top bracing? That's often a flatter arch, about 25' radius. It can be made flat, but many of us believe that arching the braces helps reduce cracking problems down the road. Many makers make the upper transverse brace flat...

Backs are usually arched a bit, so the glue surface has to be shaped to the correct curve. Often, but not always, this is something like a 15' radius. There are several ways to do this, depending on your level of experience and tooling. The braces can be glued to the back individually, using a numbe...

I normally go through the side as well. I try to avoid going through the top with the purfling rabbet, though.

Wet wood normally fails first in compression. The sides may have been too thick, or not hot enough.

I'd simply rout the back out, since you're going to replace it anyway. The trick (more often used on tops) is to make the new back first, so that you can trim it exactly to the right shape before you brace it. Once you take the old back off the edge of the rim will distort and you won't have the out...

Do the cycloid arch with the low point well in from the edge. Normally I have that at the inside edge of the liner, so I'd want to use a wider liner than usual: say 1/2"? Then you put on a wide binding that can be rounded over. It could even be laminated and solid, at least in the lower bout on...