Official Luthiers Forum!

I have some questions about bracing on the top plate:

1) do the ends of the x bars and tone bars have
-to terminate under the kerfing?
-why? just to keep the ends of the braces from lifting over time?
-If we want a top to be flexable at the rim how does this help?

2) do the soundhole re-enforcment strips:
-do not touch the x braces?
-butt against the x braces?
-be buried under the x braces?

3) same questions for the bridge patch?

thanks

Arie: Some folks do and some don't. I do and figure it's good insurance against a peeling brace. But I do take the braces down quite thin,about .040 or so. If you plan on not capturing your brace ends,I would suggest you do it to the upper ends of the X brace at least.Because of the downward pressure around the sound hole there may be more of a tendency for these to let go. I use braces at the sound hole of about 5/16 " height and butt them to the X brace and the transverse brace. Some folks may chose not to butt them. I don't put the bridge plate under the braces simply to allow an easier removal if needed,it is just butted tight to the X brace.Some folk do capture it with the braces. Have fun.
Tom

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A person who has never made a mistake has never made anything!!!

If the tonebars and Xbraces do not extend under the lining then they should at least be tapered to zero at the ends. this will help eliminate a stress riser at the end of the brace and greatly reduce the likelyhood of the glue joing starting seperation at the end of the brace. Frankly it is best to taper to zero slightly under the lining or use a jointed and glued up inlet connection.

My rule of thumb is that any brace you can't taper to nothing at the end needs to be inletted. And the taper better be pretty long, too. There's enough downward force on the upper ends of the X braces that I would strongly advise not taking those to nothing at the ends, so they certainly need to be inletted, as does the upper transverse brace. After that it gets more optional.

There are different ways of doing the soundhole braces. I make them a bit bigger than usual (say, 5/16" square), inlet them into the upper arms of the X braces, and take them through the upper transverse brace to inlet into the neck block. This 'A' brace is a lot more effective, IMO, than the 'popsickle stick' in keeping the neck from shifting inward if (when) the guitar gets dropped.

Mario will tell you that the bridge patch _must_ butt tightly against the arms of the X brace, or you will lose sound. I've never noticed a problem that way, but hey, who am I to argue with Mario?

Some people do inlet the bridge patch into the X braces slightly. It might help some to keep it from peeling up, but then, if it ever does, or it cracks, it makes the repair a whole lot harder. Pity the poor repair person. If you do the patch right, and use a right piece of wood, it should wear out long before it peels or cracks, and that can be fixed without removing the patch.

One consideration that should be mentioned regarding the soundhole braces... If you are planning to install a pickup with soundhole controls, tall braces make fitting the controls a hassle.
You have to either carve down the braces or build up the area "behind" them. A minor point, but one that's caught me a couple of times.

I tuck my upper transverse & upper X braces into the linings. All the rest are feathered to nothing before they meet the linings.

My experience with not butting the bridge plate into the X is not a good one...

I built 2 guitars this way and have ended up needing to shim both plates tight against the X brace... I am talking about an 1/8" gap between the bridge plate and the X-brace legs...

The effect I have seen...
1. Weird sink marks that start at that exact gap and radiate down the top just inside of the X-brace legs.
2. Makes the guitar too "Wooshy" or "Bassy" once you get the bracing sufficiently light... you can compensate for this with a bridge that is too thick and then leaving the rest of the bracing too thick... but being forced to build extra heavy defeats the purpose of trying to build light!
3. The Gap seems to cut down on sustain, "Zing" and the high quality crisp treble sound.

I haven't done the same experiments with Sound Hole reinforcement... but I personally think gaps north of the bridge are a very bad idea structurally.

But... I would also advise you to experiment a little... Try it out if you are curious.. Everyone told me not to do it.. No one would give me any sensible reason why though... I am really not in to "Voo Doo" .... so I had to try it out to see... and I feel like I have an advantage that I have a better mental model for it.

For example... Everyone also said "Don't leave gaps at your tone bars junction to the X" -- and leaving those gaps seems to have worked out quite well... so far...

Best of luck

John