Bracing kit from LMI

[naccoachbob]

I just received a set of preshaped braces from LMI that should brace the top and the back. I'm thinking that there was a mixup on their part about the correct pieces they sent.
I tried mixing and matching, but cannot figure out if I have the proper bracing for the back of the guitar. I am thinking the back braces are larger, almost near the size of the UTB. And when I try matching up something for the back, I feel like I don't have enough to complete all the top bracing.

I'm including a picture that shows the following from left to right:
1. sound hole reinforcement
2. upper transverse brace
3. the flat brace that goes above the upper transverse brace toward the neck.
4. Two 7/16" high by 5/16" wide braces
5. Four 1/2' high by 3/8" wide braces
6. Two 9/16" high by 3/8" wide braces
7. Two 7/32" high by 3/4" wide braces



Am I missing something? I have a set of their plan for the Dreadnought that should arrive tomorrow, so I can bounce these against that. If anyone can walk me thru what I have, it would be much appreciated.
Thanks,
Bob

[Kevin Sjostrand]

Hey Bob,
I haven't ever purchased the premade braces, but it looks to me like you have plenty there.
The two long wide flat braces are for the lower bout back, according to the plan that LMI sells. Then you'll use two taller narrow braces for the upper bout area. Then you have the flat 1" wide brace for the area under the fretboard extension, top braces now, the thick brace is your upper transverse brace, the one you'll put a hole in for truss rod access. The you should have braces long enough for the X brace and all the finger braces and lower tone braces. And it looks like you have the brace to cover the back seam too.
Does that all make sense?

Kevin

[naccoachbob]

Kevin, looking at it that way, it does make sense. I just didn't recognize the two for the lower back. I was expecting them to be much more like the UTB. The brace for the seam on the back came separately, and is not in the picture. But now it seems right. No pun. My only frame of reference was the StewMac Dreadnought plan that I have from my first kit. Tomorrow I'll have LMI's, so I'll just go from there.
Since I didn't think I had all that I needed, I ordered some brace stock from LMI as well. Perhaps now I'll start making my own, especially since they have to be radiused anyway.
Much appreciated,
Bob

[naccoachbob]

I hope someone comes to this post because now I have another question.
The two back braces for the lower bout are 1/4" high and 3/4" wide.
If I want a 15' radius on the back, how can I do that with these braces?

[darren]

You should still be able to radius those braces.

[naccoachbob]

Darren, it tapers the 2 back braces to their very edge at each end. Is that ok? Doesn't leave anything to slip into notches on the sides. Actually, I'm not opposed to those being feathered to the ends. I'm thinking of making this back pretty loose.

[johnnparchem]

I have used the wide 1/4" tall braces on a couple of my guitars. I did put the 15' radius on them. I did not taper them to nothing; I taper to about 1/8" and inlet into the kerfed lining.

Fgallery5-40.jpg

Given that you bought some spruce for bracing you can also just make the 2 lower braces the same width and height of the upper 2 braces. I currently make all of my back braces the same width and height.

Here is a picture of the same sized guitar with thin tall braces.

fgallery2-6.jpg

I think in this case making the braces to your plans or modifying the braces as you and others have described will all be good options. I think it comes down to what you want.

[Kevin Sjostrand]

Same here Bob, I put those wide braces on my first guitar and was able to radius them to 16'. You should be able to do it.

Kevin

[naccoachbob]

Thanks all. I've got to figure a bracing jig out since I don't have radiusing dishes. Or, hmmmmmmmmmmmmm maybe if I talk nice to my wife (Grin).
I'm gonna give the short wide ones a try.

[johnnparchem]

A radius dish is very nice but if you want to make a tools with the correct arcs go to http://liutaiomottola.com/formulae/sag.htm.

It shows you how to draw and arc of a big radius. From there you can cut out the arc from a board and use it as a sanding surface for the radius.

I hate sanding so for a 15" radius I also have found I can first get really close with a plane by taking a brace and marking it mid point. I mentally and loosely divide each half in quarters do four strokes on the end quarters 2 strokes half way from the mid point of each half to the end and a stroke from the 3/4 point on each half to the end. I check that against a guide to see how I am doing matching the curve and adjust the strokes accordingly. It takes me a few rounds of this and I am loose enough from where I start that I smooth out any facets I may be making. You can see you are progressively taking less off as you approach the center. For the 25 ft radius I start with fewer and longer strokes making less of a curve.

I clean it up on a radius disk, but a sanding bar with the correct radius will work as well if not better.