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Just wondering about the pros and cons of Hesh's system here. I've seen mention before of keeping the upper transverse brace flat in bracing the top, and I've seen sanding a flat on the top to give a good mating surface for the fb overhang, but this is the first I've seen anyone sand the rims flat in the upper bout. It looks like a good system to me, but wanted to hear some thoughts.

Is this one of those "luthier secrets" finally revealed?

And what is the downside?

Thanks,
Joe

ps. I posted this first in the wrong forum, under tutes, my bad. If someone can delete it there, thanks.

If you make the UTB flat and the upper bout rims radiused, you have to crank down on the edges of the soundboard's upper bout to make them sit flush with the rims.

Flattening the rims at the upper bout makes the flat UTB sit down on the rims with just a little North-to-South soundboard flex, which builds in a nice amount of fretboard fall away in my experience.

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Evan McCartney

This is a common technique used by lots of luthiers.

Joe: Started building using David Russell Young's book and this was how he did it although it was done without radius dishs. Have never done it any other way and when I started using dishs I continued to keep the UTB and any thing above it flat. Have never had a problem.
Tom

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A person who has never made a mistake has never made anything!!!

Joe...there's nothing secret about this and the method has been used for a long time. Check out John Hall's You Tube videos. They're the best on the planet IMO.

I've been using John's method for years where he adheres sandpaper to the flat of his radius dishes and sands in the flat. He also has a hole drilled in the center of his dishes and rotates them around a pipe nipple. I don't want to oversimplify his method so be sure to check out his 3 or 4 videos that deal with side geometry. Here's a link to the 1st in the series http://www.youtube.com/watch?v=JFNy93PM0Kc The part on sanding out the upper bout may be in the 3rd or 4th part of the series but it's worth it to view them all.

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JJ
Napa, CA
http://www.DonohueGuitars.com

Thanks for the replies guys!
Always something new to learn, that's the beauty of these forums. Somehow I never came across this method and I thank Hesh for the tute! I've already sanded the upper bout flat using this method on a plywood Japanese 12 string that needed a neck reset. And I'm re-topping it with a lutz top while I've got it apart, so this was very timely.

And thanks JJ, I'll check out John's videos.

Joe

Anyone close to me:I have a 24" HORIZONTAL disc sander that's in my way. 3 phase. Just right for mounting a rotating radius dish on it.