Official Luthiers Forum!

Do you guys carve your brace on or off the plate?

I started experimenting with carving braces off the plate. It is so much easier to carve it without worrying that I will dig into and damage the top, and it also seems to keep the top so much cleaner. And instead of messing around with special chisels (like those curved ones) I just use a robo sander to carve it before gluing it on. All I had to worry about when gluing is to make sure the top stays clear of glue.

Last top I did when I carved it on the plate, I made a huge mess of the room (in an effort to save electricity I carve it in my bedroom where I can keep the AC on without spending too much on electricity), and I kept digging into the top, not to mention by the time I'm done the backside of the top now looks all dirty from all the handling.

Or do you clean the backside up by sanding it after you finished carving?

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Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

There are lots of people who do it one way, and lots of people who do it the other way.

I prefer to glue rectangular profiled braces to the top, then carve the braces after gluing. I use some thin plastic scraps at strategic spots to keep from poking divots in the underside of the top while carving. Using a finger plane for some of the carving helps, too. I also sand both the top and the braces afterward.

I would say that even the folks who profile the braces before gluing will tinker with the braces after gluing. So, they are carving after gluing, too; just not as much.

I carve after gluing on the top plate. You just have to be really careful and of course you have to have a razor sharp edge. When I carve brace ends that taper down to zero I use a small arched finger plane to hog away the big stuff and then use the LMI "Glue Chisel" to VERY carefully remove the rest to a feather edge. The small finger plane is great though, it's made of wood and rounded so if you miss a stroke it will not damage the top. You might want to handle the chisel a bit differently. Instead of taking long direct strokes try bumping it along and even using it almost like a saw, sawing the blades tip side to side as you slightly push forward.

What advantage does gluing a square brace stock onto tops and back and then carving have, other than being easier to clamp? 90% of the braces are going to be removed in the same way, might as well remove them first, then tweak it once everything is glued on?

Another difficulty I have is keeping the top from moving around so much when I'm trying to shape the brace. I'm afraid to clamp it to the table because I might damage something.

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Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

There is certainly nothing wrong with doing it that way Tai, many luthiers do carve first then glue on. For me yes, it's the clamping. Much easier to clamp. Then of course you are free to voice the top any way you want. I don't really do that per se so it doesn't matter. I mean I like to pretend I voice the top but really it's a guessing game. And like you said you can always tweak a precarved brace, just don't pre-carve it too far before gluing on.

As for holding the top. I have a carpeted work bench and I fold a towel to accommodate the arch in the top.

I carve on the plate, it's easier to use the go-bars on that way.
Washing your hands before working helps a lot to keep the plate clean.
I use a 1" Narex paring chisel upside down for scallops, no need for curved chisels.
Safe edge the corners on the chisel (round them off slightly)
Sometimes use small wooden planes as well (Chinese ones, I shape the soles myself)
I did use thin plastic guards, some with cut outs for the brace ends, taped down, or even few layers of tape to help me stop digging in until I had more practice at it.
I also leave off any sanding (after brace gluing and glue clean-up with water) until after carving the braces.
I carve the braces with the plate on the appropriate radius dish with non slip matting on top to cut down on movement.
One finger of the chisel guide hand on the workpiece is enough to stop any movement if your chisel is sharp, which it should of course be.

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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 don't have any finger planes. They're incredibly expensive, even the cheapest one is quite expensive. I use Chinese planes because it's all I can get and they're cheap. I think I can probably use a dremel sanding drum to final shape the braces.

I'll probably start making my own finger plane out of scrap wood and lathe parting tool blanks if the need arises.

I'm even going to start making my own guitar reamers. I can find cheap taper pin reamers and I'll use a rotary table and a cup wheel to grind it to the right size and taper.

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Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

Other than wanting a project, it hardly seems worth the wotk of making your own when you can buy ones like this so inexpensively https://www.ebay.co.uk/itm/1pcs-convex-bottom-brass-wrap-blackwood-1-1-4-planes-violin-viola-making-tool/264337565335?hash=item3d8bbf2697:g:PtkAAOSwRMtZZH9a

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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.

My view (and certainly many folks see it differently): Rectangular braces are easier to clamp than braces with an arched profile. I can arch the profile in a few moments of carving after gluing. I can protect the top from major stabs that could happen during carving. I either carve braces inside my go bar deck while the top is held in place by a go bar, or use a large, padded spring clamp to clamp the top to a workboard. Either works fine.

If I were trying to build a whole lot of guitars at once, in a factory setting, I would want to pre-shape the braces in a mass-produced fashion, then carve a little after gluing. Building one guitar at a time, I don't see the value in pre-shaping braces. It's just another step I don't need. To each her/his own.

WOW! Those are vey inexpensive. I bought a set of 5 solid brass finger planes from China on Ebay, maybe 6 years ago. They cost maybe $70 for the set, I don't remember. One name brand finger plane was about the same price. They needed extensive rework; my wife says I can't leave ANYTHING the way that I get it; (but they needed it!) and I put laminated Japanese blades on them. Now they are great. They could use bigger thumb screws, but....

Wooden bottoms would be easier to rework, but will wear faster.

I can carve a bass bar down in just minutes with them, and I don't have to worry about slipping like you would with a chisel. Chisels are handy, but not there. I do use chisels to taper the sides, but that is less risky.

I don't usually clamp anything down to work on it. But then I'm weird.

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Why be normal?

I guess the other subject is, how do I sand between all the braces to clean everything up? Doesn't seem like a lot of room for me to move the sandpaper. Maybe I have to use those little vibrating sander in a triangular shape (which means spending money on yet another power tool)

_________________
Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

Spend 30 cents USD on a pink rubber eraser and attach PSA sandpaper to it. Power tools are not all that useful for the kind of sanding in question.

It's the inside of the guitar, don't worry about it. IDK why but that always drives me crazy. I leave plane and chisel marks on my bracing intentionally, I don't sand them. I like to see the hand of the maker. If there is a little discoloration on the inside top of the guitar who cares? But if you must, then like Don says, little rubber erasers make great sanding blocks. Razor blades with rounded off corners make great scrapers too.

I glue first, both for easier clamping and because I have a harder time holding onto loose brace blanks for shaping than I do carving them on the plate (I don't have a robo sander).

To keep clean, wash your hands before working. Even with that, it will absorb some sweat, but inside it's not enough to worry about. Outer surface should be shellacked to keep it clean throughout the build process.

As Colin says, a chisel with rounded corners is good to keep from scratching the soundboard.

It is safe to clamp one point on the soundboard at a time. Then use a bench dog or random piece of wood clamped to the bench to keep it from rotating. And a sharp chisel so carving doesn't take too much force.

I have a finger plane, but I don't use it much. Chisel is generally faster.

Unless you screw up, there should be no need to sand after gluing the braces. If you do screw up, try a scraper. Razor blades make good scrapers when you need to get into a tight spot or right up against a brace.

Once the braces are glued, there's no need to worry about humidity until it's time to glue to the rim. And even then it's far less critical than for brace gluing. If the soundboard curls into a potato chip and gets stuck that way, then it was doomed anyway (that means the wood moisture content when gluing braces was higher than you thought, usually due to not accounting for hysteresis when acclimating to different humidity levels).

The bracing on some of my classicals is less than 1/8" tall, making shaping on the plate difficult. For those, I have a piece of 1 by with a ledge routed into the edge. I clamp these with a HHG rubbed joint, so no clamping.





The second pic shows what I do for the taller braces, even though they haven't been shaped yet. Works really well for pre-shaped braces and cuts down on braces tipping over and slipped go-bars that dent the top. Ends are tapered on the plate.

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

I carve on the plate. Here is my reasoning. First of all much easier to glue braces up on a go bar deck and not be concerned about divots from the bars, since they get carved out - not to mention, clamping up (unless using vacuum, but that's another issue) is far easier on square stock. Same goes for rub joints with hot hide, just easier to do with square stock. Next I prefer getting a feel of the top while bracing. Sandpaper is not used on the brace, just small carving planes, or chisels on brace ends. On cleanup. I always use hot hide glue. It cleans up well during glue-up. But that said, any OCD desires - just some 320 grit pushed parallel to top grain. Use a push stick if really picky about holding down the paper, but folding up the paper typically gives enough backbone to the paper to get right up to the edge.

It's really not OCD. That's shorthand. There is a term of art, hidden beauty. It is the idea that a craftsperson embodies all their work, seen or not, with the care and style which reflects their craftsmanship.

Some advice for doing it on the plate.

1. Sharp chisels are an absolute REQUIREMENT for this work. If you're slipping and digging into the top it's likely that you're having to try too hard to cut with your chisels. Dull chisels are not allowed.

2. Wash your hands before working with light colored wood. Or wear some latex gloves to keep your oils off the top.

3. Use a chisel to remove glue squeeze out. It's extremely easy to make some simple scrapers to remove the glue. Or if you have a spare chisel around 10mm wide take a torch to it and put a slight relief bend in it.

4. Finger planes have been used for centuries by great instrument makers. They are very cheap on ebay.

Doing it on the plate lets you feel how the top will respond to taps (if you do it that way) and also helps you control the depth and height. If you do it off the top then the brace will flex a bit and then you'll end up with a wonky cut. Doing it on the top is the way that pretty much every major luthier I can think of does it.