Help with brace shaping on first kit guitar

[Chuck Dvorak]

I've glued braces on to the top of my kit guitar, and now I've hit a bit of uncertainty. I'm experiencing paralysis by analysis.

I'm working on a Martin OM guitar kit from John Hall. I'm using Bill Cory's guide to building Martin Guitar kits to lead me, as well as reading plenty on the internet, books, magazines, as well as viewing John Mayes' DVD video on Advanced Voicing. I've read some suggestions that the first kit should really be an exercise in learning the basics of how the guitar is put together, and not getting into the fine detail. However, I still think it would be useful to take small steps in trying to improve on the tone of my first kit.

I'm considering the following adjustments:

1) Adding a cap to bridge the joint where the x-braces intersect

2) Shaping the finger braces to a more parabolic shape, they are currently rectangular

3) The ends of the x-braces and transverse brace will be inlet into the kerfed lining. I would like to feather down to nothing the ends of the finger braces and tone bars short of the lining.

4) I would also like to feather the ends of the tone bars and finger braces where they meet the x-braces.

5) The x-braces and tone bars are already rounded over, but I may consider lowering these to improve tone.


Would anyone be able to advise me on these ideas for a first build? I would also appreciate info from others on how they approached brace shaping on their first kit guitar.

A picture of my top in its current (unaltered) state is included below.

Any help is very much appreciated. Thanks!

Chuck

[enalnitram]

1. a small circular piece of linen soaked in glue will work. I did that on my first, with pre-made Martin braces. On my second, I glued a spruce cap going across the X, but the tops were flat at the intersection, as I built em that way.

2, 4 & 5. You might want to browse this thread, and copy the shape and look of these braces:
http://theunofficialmartinguitarforum.y ... BRARY.html

There are some pictures of OMs and 000s with scalloped braces in there, play it safe and copy them.

3. Sounds good to me.

My first guitar was a 000 Martin kit. I pretty much left the braces as is, but did shape them a little by copying pics of 30's guitars.

[kencierp]

I think copying an instrument wtih sound qualities that appeal to your ear is a good idea. Bob Taylor did a piece awhile back and one of the main points of the article was that each and every guitar has its very own personality. So it is impossible to tell what effects the minor changes you are considering might have on the instrument you are constructing ---- for one it will be subjective -- and secondly there is no way to actually compare what you've done. Note that of all the years I've participated in this forum I have yet to read that someone thinks they have built a "crappy sounding guitar". So no matter what you do, mostly likely you'll be safe. I personally believe a very tight fitting X brace intersection is important (I use epoxy) so if the joint is not precise a cap of some sort would be in order.

[tippie53]

In all my years of repair I never had an issue with a cloth strip but have repaired many caps , the braces you have are not designed for a cap so use the cloth and be sure to use glue in the joint ,. That will secure things very well .
You can work the finger braces as you choose. they do little in tone they are more an anti split braces. Also be sure you break any sharp edge.

[Darryl Young]

Chuck, I have little experience so take what I'm about to say with a grain of salt.

One thing I would caution against is feathering the top tone bar down to nothing where it intersects the X-brace. I would leave some meat there to provide stuctural support to resist bridge rotation and on my build Mario Proulx advised me not to feather it all the way down. You can go down some.......but not all the way. On the lower tone bar I think it's fine to feather down all the way......and in general it seems this brace needs less beef.

I'll give one other opinion, I don't think it buys anything to inlet the braces. However, you do need to make sure you have glue on the end of the braces so the are glued not only to the soundboard but also to any other braces it contacts.

[Chuck Dvorak]

Thanks to everyone for the advice. I'll see if I can find a good design to "copy" as best as I can and make notes and measurements for future reference. I appreciate the cloth cap suggestions, too, sounds like the right way to go.

Chuck

[tippie53]

here is a link of to photos of different bracing. http://theunofficialmartinguitarforum.y ... /topic/847
A note for you for future reference . Any brace that will get glued to another should have a good clean contact surface. A brace that will not be inletted into the kerfing will have to be thinned as to fade to the top. The vibration will cause the brace to loosen otherwise .

[klooker]

I'm working on my first build but I do have woodworking experience. I scalloped & tapered the braces according to a Stewmac drawing. I'm not sure if their OM plan has the same details.

I used a razor sharp chisel with the bevel down & only made cuts when going down hill. I also held the chisel close to the cutting edge and kept my hand (near the edge) in contact with the top when cutting. Always think about the worst that could happen if the tool got away from you & adjust your technique to minimize the potential damage/heartbreak.

After rough shaping with the chisel, I went back with sandpaper to smooth things out.

Kevin Looker