A few design decisions were made along the way. At first a five layer brace for the top was the plan. With the use of two layers of carbon fiber between three layers of mahogany. Instead to decrease the surface area to allow for more resonance a three layer brace was used with only two layers of two wood and one carbon fiber.
To provide the strength we need the center braces are extra tall. The strength of them grows proportional to the height. The main stress on the guitar is on the bridge and down the neck. So the structure of the braces reinforce that area the most
After the braces are glued onto the top, it is put through a process we like to call torque tuning. A weighted arm is put on and we measure the amount that the arm bend. By a simple calculation we know exactly how much deflection we need for a minimally braced top. The braces are sanded until we are satisfied it will be strong enough and responsive enough.
Here are the pictures documenting the process. Enjoy!
First are the materials used for the braces. Carbon fiber and mahogany
The wood is bent while dry and kept in a form by clamps
Lots of clamps are used to glue the layers together. We use a 2:1 epoxy for this.
The braces are placed on the top and the best placement is considered.
Here’s Jay sketching out the brace position
Then the extra brace is trimmed
To glue them in a go-box is used with tension rods. Glue is slippery and sticky, so care is used when placing the rods.
The height of the back braces is about a half-inch. Less brace is needed on the back because it doesn’t need structural support it only has to hold the shape in place
Onto the top, Lots of bracing going up the bridge to the fretboard. It must support about 160-200 lbs of tension from those strings.
The brace height is higher.
The back braces are shaped to look pretty
This is the setup for our torque tuning. The top is clamped down simulating the stiffness of the sides. A lever arm is attached at the bridge and the weight is put on. We measure the bend.
The braces are sanded to decrease the stiffness
The amount of bend
The finished top!
Thank you for reading!