Acoustic Guitar Construction

How thick is the sound board now?

Too thick - about .105"

Here's a pic BEFORE I really went to town thinning the braces.

I'm thinking of 3 approaches

1. scallop these braces - I have not done this in the past with thin braces, but removing a bit of wood in the middle can only help.

2. Once upon a time, Brian Burns was using his ingenious testing device on a rim and a glued on top. He tried the following:

- fitted the back onto the rim and TAPED the back down securely. Tested.
- then GLUED on the back and after drying, tested.

The results were the same. So: I may just go ahead and notch the kerfing and fit the top and TAPE it down, and then do some sanding, undo the tape, do some flexing and tapping, and continue that way until I'm satisfied.

3. With the top taped in place, I can use a drill to put holes in the top to the depth I want, then sand down to get rid of the holes, and like that.

What do you think?

I'd scallop those braces and also feather the lower bout using the Teeter spot depth system if necessary. The bridge plate looks much larger than the normal 1.5" wide?

So you are building a lefty?

Scalloping it shall be, followed by a good Teetering. Thanks.

Dave, here are some pictures of two 00-12 Frets that I've been building (KMG Template) - I still have a long way to go in refining my sound, but this gets me headed in the direction I want to go.

I use .250" braces, and prefer to scallop them. On the figured maple 00 I tucked the lower ends of the x-brace into the kerfing - it is a bear claw Sitka spruce top that was a little more flexible, so I'm working to stiffen it a bit without the added mass of a too thick top. On the Ziricote I tapered the lower x-brace ends before the kerfing as it was a stiffer than average sitka spruce top.

On both I used a maple bridge plate that are about .095" thick - these will have solid bridge pins, with slotted bridge.

This is the stiff sitka top on the Ziricote body prior to final cleanup and sanding of the braces (just roughly voiced in the pic)








I remove a lot of wood from my braces:

I would first go after the tone bars, you can scallop as suggested or just plane the braces you have down a bit. The way I was taught and follow is to hit a few target spots to shave down the braces all the while tapping. If after making a change and it sounds better, you found a significant area; take some more off in the same place. If it really did not help select a new target. I will work around the tone bars first and then the x-braces. A little goes a long way. The top is probably within 7 thousands of what it should be.