Official Luthiers Forum!

When it comes to braces being glued to the plates, I think we can safely rely on the notion that both planed and sanded surfaces, if well fitted, meet or exceed the design requirements for acoustic guitar braces. Whether one is stronger than the other probably matters as much as the difference between drowning in 10 feet of water versus 12 feet. At least with normal use. If you go all Pete Townsend on the thing, maybe having the strongest joints possible matters.

How the joint looks, however, might be an issue in other parts of the guitar. I noticed on a glued heel block, for instance, that either a planed or finer grit sanded surface might look better when that part of the neck gets carved and the glue joint looks like a big C. I think I would like to see a crisper, thinner C.

One thing that hasn't been discussed is the position of the brace on the back/top, and how that position relates to how the brace sits on the back/top.

For example, a lot of methods for putting a radius on the brace have been discussed above, but they all have the radius put perpendicular to the brace edge. On a back, if all of the braces have square edges, all of them will glue up perpendicular to the back. This means that the braces towards the neck and tail will end up leaning in towards the waist area when glued flush to the back. Structurally, I don't have any problem with this. But I like my braces to sit vertically to the dish, no matter their location. So I sand mine in the dish using the approximate location they will sit when glued up, making sure that I am keeping the brace vertical (old, bad photo below). This results in a slightly beveled edge unless the brace is located directly in the center of the dish. When I glue up in the dish, they sit straight up and don't cant toward the middle of the dish. I also find the go bar clamps have less tendency of knocking the brace over.



I think I started doing it this way on my first build while following O'Brien's LMII tutorial disk. I've tried keeping the edges square, but just don't like the way the resulting braces cant towards the middle. Granted, when the box is closed, no one is likely to notice.

Just a thought to add to the discussion. Lot's of ways to skin a cat......

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Tony Thatcher
Bozeman, Montana

Many way to skin the proverbial feline.
Max angle in a 15' radius back for 1st and 4th braces is of the order of 2 degrees, not exactly huge, and I like to see them (more or less) vertical anyway.
I use carpet on the top deck to help secure that end and just angle the go-bars a little.

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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 started using your method. Much quicker also


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