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I have built two radius dishes, 15' and 25'. 80 grit paper attached. I have been cutting braces from some nice sitka Shane sent to me. I have been using the 15' dish to shape the braces, this question is about technique. Do you hold the brace so that the pressure point is over the center of the brace, or at two locations approaching the radius of the dish?

Mike

Hey Mike,

Your goal is to end up with a brace that matches the curve of the dish when oriented the way it will be in a guitar. If you just press down in the center, you'll flex the brace and will sand a profile that changes when you let go and it relaxes. It is also likely that wherever you hold the brace, it will wear material faster in that spot, so do it strategically to sand where you need it. Probably, you'll want to hold it out near the ends for a bit. Then when you've sanded the ends too much, hold it in the middle.

Tracy at Luthier Suppliers (see the top of the page) has a cool jig that lets you speed things along in a jointer or tablesaw. It works great. Not hard to make your own, but if you're anything like me, his is way better.

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Mike Lindstrom

That sounds like what I am doing. Just checking, Thanks,

Mike

Mike my friend I just trace the proper profile on the brace stock and then initially sand the profile into the brace on a belt sander - very quick.

Then I tape two braces together to add rigidity to them to avoid flexing in the center and then sand the final profile in the dish. Two braces taped together also is easier, at least for me, to hold onto. Also I wear a latex type glove too also to help me hold onto the braces in the dish and keep them oriented upright while sanding.

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Ann Arbor Guitars

if you have a true radius dish , it shouldnt matter where you sand your braces on it, flex could be an issue , the only problem with the shaper jig is you can get some tear out .so I would make a few spares just in case ... Jody

Hesh, where did you find sandpaper in large sheets to cover your dish? I had to piece mine together.

Mike

Mike I get it from John Hall at Blues Creek. The 80 grit seems to be the favorite here.

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Ann Arbor Guitars

Cut the curved braces on the table saw and they will all be perfect all of the time. No sanding required! See http://www.wellsguitars.com/Articles/Curve_Braces_Article.htm and http://www.wellsguitars.com/Articles/Revised_Brace_Cutter/Revise_Brace_Cutter.html.

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Sylvan
http://www.wellsguitars.com

I use the Luthier Suppliers radiusing jig.

Hesh,

Alrighty! I will get some of that. Thanks for the tip about preshaping. I did that on my Rigid spindle sander. Saved a LOT of time and effort.

Gonna check that thread on shaping with a table saw...

Mike

OK, that is way cool. Do you use this technique? I think I would be more inclined to use the bandsaw for this.

Mike

Mike I use my table saw to cut my braces (radius that is).

My jig is really simple (takes some layout though, which I did in cad) and I also use it for cutting the taper on my fretboards.

Here's a few pictures.

The base is a piece of 1/2" Baltic birch plywood. It has a runner on the bottom to sit in the right hand side miter slot (cut the board to size after the runner is on, makes the edge perfect)



out on the ends are two 1/2" dowels (removable so I can cut fretboards), this is where the layout comes in. The brace is centered between the dowels and pressed to to the edge of the base, this makes the radius in the brace. (this is just a scrape x-brace used for demo purposes)



Run the brace through the saw blade and you're good to go (and if you have a good blade, it might be ready to glue right off the saw)

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Thats cool Rod. So you count on the "spring back" to be at the proper radius. Is the radius of the jig the same as the desired radius or do you have to somehow "compensate" with a smaller radius?

Mike

As seems to happen all too frequently when there are pictures in a post, I got dumped and couldn't see them. However, I'd like to point out a common problem with springback setups that you may or may not have. If you just push the brace down in the center you won't end up with a truly radiused brace; the center and the ends will touch, but it won't be in contact in between. You end up with a sort of parabolic profile.

I've put the radius on braces for years using a hand plane. I stick a thin shim on the sole of the plane with CA, and it makes perfectly radiused braces. I clamp them together and do four or five at a time, which helps eliminate the one real problem with the technique; the tendancy to roll off to one side or the other and end up with a twisted surface. It might not be quite as fast as the table saw jig, but for those of us who don't have a table saw it's quick enough. You also end up with the best of all possible gluing surfaces, a freshly planed one.

I'd read Al posts about this method many times, but I tried it for the first time not long ago. It works really well!

I do it a bit differently than Al, though. I trace the radius profiles from the dish onto the brace blanks with a spacer (pencil in washer), rough out the curve on the long belt sander, and then plane. Ideally I'll get one long, even shaving from each brace, and I'm done. Since I'm planing a curve, the plane is going against the grain on half the brace, but with a fine mouth setting and a very sharp plane its not enough to cause any problems. This could probably be done before the braces are sliced into individual pieces, too. BTW, I don't use the shim that Al does, and it still works.

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Rian Gitar og Mandolin

Arnt Rian wrote:
"BTW, I don't use the shim that Al does, and it still works."

Then with all due respect, you're missing the point. It's the shim that makes the plane cut the exact radius, constant from end to end. With a freehand cut you can end up with corners or flat spots. Besides, this saves the steps of tracing the curves and cutting them on the band saw. Obviously uyou do need to have a sharp plane that is set up to give a smooth cut against the grain, but you should have that anyway.

Am I missing something? If you have a sanding dish then why would you need another jig? I think Hesh's idea is a time saver.

You dont Chris ... but the radius jig works faster than sanding by a long shot .. and they are not hard to make. By the time you (or Hesh) sands three or four braces, I can have two or three guitar top AND back sets done, and then ready to plane the joint surface, which again takes only minutes .. far superior than sanding. I do the initial cut ont he TS,then hand plane shoot) the brace bottom in the jig

They may not produce a perfect radius .. but they are certainly close enough for me.

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Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"