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I have some cheap guitars I'd like to shave the braces. I can do very little with the tools I have any suggestions?

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Hutch

Get the heck off the couch and go build a guitar!!!!

Something like this?
https://www.amazon.com/Fityle-Woodworking-Carpenter-Woodcraft-Smoothing/dp/B08HJ6B68N/ref=sr_1_16?dchild=1&keywords=Wood+Planer+Hand+Tool%2C+Thumb+Plane%2C+Wood+Hand+Plane+Tool+Mini+Plane+Wood&qid=1629057196&sr=8-16
Or this?
https://www.amazon.com/Unxuey-Trimming-Woodworking-Woodcraft-Instrument/dp/B07T53G6NL/ref=sr_1_16?dchild=1&keywords=Wood+Planer+Hand+Tool%2C+Thumb+Plane%2C+Wood+Hand+Plane+Tool+Mini+Plane+Wood&qid=1629057312&sr=8-16

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

I prefer the wooden ones for making convex soles if scooping braces.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Sticky sandpaper and your fingers

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http://www.Harvestmoonguitars.com

I can do very little with my violin planes. Sticky sandpaper might be a good way but very slow. I'll give it a shot.

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Hutch

Get the heck off the couch and go build a guitar!!!!

I reached in with an Xacto knife with the curved end blade. Can't say I was very precise.

This might be a bit quicker (maybe too quick!) but you might want to shorten the handle (or not):

https://www.woodcraft.com/products/pfei ... made-scorp

I don't understand your "violin" planes not working well.

I have a couple Ibex finger planes with round soles. They're probably my most trusted tool for final carving of braces. Probably the only tool for carving a curved surface blind that I'd trust to the point of feeling totally comfortable.

I love 'em. Push them or spin around and pull, no problem.

Of course now you can get little USB cameras and look at the inside of a guitar, even with your arm in the hole.

Next best thing to being there.

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Brian R, Wood Mechanic
N8ZED

This topic comes up every few years. Here's a thread I posted to a while back.

http://luthiersforum.com/forum/viewtopic.php?f=10101&t=51154&p=673560&hilit=spokeshave#p673560

I usually pull it. Still my fave.

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formerly known around here as burbank
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http://www.patfosterguitars.com

I've used finger plans and they worked well. You are working blind so having a good feel of what the tool is doing is important and being able to reach into the box far enough is necessary too.

It is hit and miss though and your results are subjective in the sense that there are lots of variable here. The one of my own that I did this on was number 6 I believe and I was still searching for my own bracing style and patterns. So I overpriced the hell out of my first attempt at "tapered" or parabolic braces.

That guitar benefitted from some scalloping and material removal but I can't prove that what I hear is any improvement. What I suspect that I heard was the emergence of something that was lacking, more bass. And that is exactly what I would expect as the top gets floppier and the Helmholtz response changes.

I would never do this commercially by the way again it's too subjective and hit and miss. In the case of the one I did I did want to use that guitar so it was worth while. But is there any real learning value in the exercise in my view, no. Doing to improve an instrument, hopefully that you want to use but as something to learn to be a Luthiers it's not something Luthiers commonly do commercially and with good reason too we are dramatically altering an instrument with no guarantees that any value will result.

Just want to give you a North Star that our commercial shop uses to guide us in what we take on repair wise: Is the job something that we have experience with? Is the work predictable? Has prior work made our outcome skewed? Is there a defined beginning, a defined ending and a mutually agreed upon definition of success? All these things have to be in place or we won't take the job on.

You can see that #4 is in question with brace shaving.

I did have a request from a Taylor owner for a fret job and " could I do something about the lack of bass", it sounded absolutely dead.
I was reluctant, and said so.
But when working on the fret job, I checked the rotation of the bridge under string tension - it was about 0.8 degrees. Also checked top thickness, 3.1mm (0.122") Sitka, thick for average spruce, so I felt there was a good margin there to thin the braces.. So I discussed and said I would try to work the braces.
I took very fine shavings, checking the bridge rotation often, until it reached 1.9/2.0 degrees, and then a quick light sand and stopped.
The result was not stellar, but was vastly improved to what it was when bought to me, very happy client.
I only did this because I have worked my own guitar braces through the soundhole several times, but if you're working on cheap guitars, go for it.
Somogyi actively encourages this experimentally with overbuilt inexpensive guitars, and Gore gives 2 degrees as a target for bridge rotation.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

I sure wish I had one of Alice's cakes.

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Hutch

Get the heck off the couch and go build a guitar!!!!

Specially for you....

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Save me a slice!

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Shaving braces could be quantifiable if you used spectrum analysis before and after.

Don't get all scientific on me now. I do enough of that at work and prefer to do things by the seat of my pants when I'm home.

You have me thinking though.

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Hutch

Get the heck off the couch and go build a guitar!!!!

The nice thing about quantifying is that you can figure out what the problem is. This helps with Hesh's question about defining end points. It also helps to avoid making more trouble for yourself down the road. Knowing the 'main top' and 'main back' resonant pitches, and the bridge rotation under string tension, you can see what you can try to move to get the result you want. You can also do experiments with mass loading the top/back or restricting the sound hole size, to see what's effective and get input from the customer before you do anything that can't easily be undone. Of course, you can do all of this with educated fingers and tap tones, if you're a technophobe, but that takes some time and experience to learn. If you've got some sacrificial junkers ('el kabong specials') to practice on that's a good way to start. One issue with shaving top braces is that the results of going too far may not show up for some time (as in months or even years) and a few of those out in the local music community won't help your reputation much.

Schneider brace shaving plane and a butt chisel.

Pat

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Pat

I gave them another try and they work but I still can't reach far enough to get the braces I truly want to scallop or diminish in some way. I thing some kind of rotary tool while using a camera might be the best option.

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Hutch

Get the heck off the couch and go build a guitar!!!!

I have done this to maybe ten guitars over the last 50 years but only under these conditions:
1. the guitar must be already a good guitar, well-made with a nice sound.
2. It just seems like the sound could be better and bigger.
3. I have another guitar available to me that is about the same size, braced the same way, made with pretty close the same woods, that sounds much better than mine.
I thump both guitars with a finger or thumb starting at the bridge spreading all over the top and trying to follow the braces. A little mirror on a stick is helpful. When I find a spot where the good example guitar sounds bassier than mine, I remove unbelievably small flakes of spruce from the brace under the spot. After two hours I'll have a total pile of wood flakes equal in weight to maybe two small crickets, removed a bit at a time from many locations. And my guitar is more fun to play.
If you get greedy and try to take your guitar farther than the model you can wreck the sound dramatically and the only way to fix it is to glue more spruce inside! Much better to be cautious! This is not that scientific of a procedure so think of moving your guitar two-thirds of the way towards the model.
As someone else mentioned, I only do this on a guitar that belongs to me. I like what Somogyi says about tapping.