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When you scallop braces with a chisel how do you keep from digging into the end grain on the way back up and cracking the wood down the grain?


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Come in from both ends of the scallop.

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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.

What Colin said. I prefer a small spokeshave over a chisel for most scalloping.

Pat

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

I use a razor saw in the middle of the scallop to set the initial depth during rough out, then a microplane with curved bottom to fine tune it.

https://m.youtube.com/watch?v=Lz-2OL_b-oU

Though I am not certain this is the correct method, I need a few hours after dinner with a glass of single malt. This is usually a satisfying part of the process for me.

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My memory is so good, sometimes I remember things that never happened.

I've watched that video at least 5-6 times, and never get tired of watching it!

Alex

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"Indecision is the key to flexibility" .... Bumper sticker

Funny I was just thinking about a small spokeshave. Veritas makes a killer small line:) I love the mini block plane. I bet the mini spokeshave is just as cool.

http://www.leevalley.com/us/Wood/page.a ... 50230&ap=1


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[quote="Bri"]https://m.youtube.com/watch?v=Lz-2OL_b-oU

Chisel is sharp!

We go through a number of different methods using various types of chisels and shaves with build students, but most end up preferring the double bevel carving chisel, which makes a bit of sense if the task is carving a brace. For the initial rough shape of the brace (before voicing), a quick V-cut to depth with the chisel works, or a careful razor saw cut as mentioned earlier in the thread.

To achieve that long, smooth catenary-like curve, approaching from either end and meeting near the low spot of the curve seems to be the preferred method...a 24" x 20" piece of 3/4" ply with a number of 3/4" diameter x 11/16" deep holes scattered in a roughly guitar-shaped pattern holding 3/4" dowels (1-3/8" long) makes a decent fixture for brace shaping work...we have a doubled thickness version with cork-covered bottom that stays put even on the carpet surfaces taped to the aux benches with double-faced carpet tape. If the grain rises/falls along the length of the brace, the mid-point of the scallop may not be where the two cuts must meet for smoothest cut, so worth working to the curve over several passes.

Good luck! Brace shaping and top voicing is my favorite building step!

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For the times they are a changin'

- Bob Dylan

small rabett plane vy sharp, and super sharp 20 deg bevel 1in long handled chisel with ends ground off 1/16in a la trev/gore book For finishing off the ends I use a 3/4in spade shaped japanese carving gouge with a #2 profile .It sharpens vy well an takes clean shavings , leaving little finish sanding. I have those small spokeshaves and IMHO a PITA to sharpen and set up for use. You might like them ?? Razor saw for thin cuts, stew mac nut file for clean ups.

For years, my go-to for brace profile shaping is a Zona spokeshave. I cut the "ears" off, so that I can reach the sides of the brace, almost down to the surface of the top. I first learned about it from the folks at Lundberg's in Berkeley, who used to scallop top bracing in Martins. For tapering the brace ends, I like a chisel with the corners rounded off.



Pat

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

I go from both ends with a wide chisel in multiple passes. I put an appropriate radius dish on the bench with a center pivot peg and multiple holes for pegs to support the top so I can stand in one Place and rotate the work for optimal access. I use a cardboard backer to protect the top.

Finger planes for beveling stuff.

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It's not what you don't know that hurts you, it's what you do know that's wrong.

In the vid at about 2:07 he takes a cut & stops. I assume he realizes that it's not going to work - too much runout?

Just armchair analysis but I think super sharp tool and exceptional cuts of bracewood, except for that finger brace at 2:07. Maybe doing several hundred has something do to with it too.

From my limited experience, I don't enjoy scalloping but I've learned a lot about runout. My best sounding guitars (both of them) have also resulted from very limited scalloping but YMMV.

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I'm not a luthier.
I'm just a guy who builds guitars in his basement.
It's better than playing golf.