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There was some discussion in one of the other threads about cylindrical tops as opposed to a radiused top. I posted the question then deleted to ask here and avoid from hi jacking some one else's topic. Does the gluing surface of the braces get shaped to match the radius of the cylindrical top? If so, what radius would you use on the X brace? I assume with a 15' cylindrical top the brace radius would be somewhere between 15' and flat?

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Kyle

A couple of good leads for you for answers are Howe Orme Guitars and Rick Turner who is a member here but rarely posts, he collects the Orme guitars.

Not sure on this one but Howard Klepper may..... have built with a cylindrical top but again I can't remember for sure.

Howard was building with cylindrical tops 6-8 years ago when I last saw him at Grass Valley.
While I was building, the Larson laminated X braces were roughed to shape on the 6 X 89 sander and then sanded by hand along the X drawn on the sanding "dish". Mine would have all been around 10'

Nigel Foster (member, but not posted for some time) also makes cylindrical tops.
He told me some time ago he was thinking to publish a book about construction, but nothing so far. I do know he's been busy moving countries.
http://www.nkforsterguitars.com/.

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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.

Like everything in guitar building, there are probably multiple ways to do this that work. Here's the method I was taught.

The top braces are radiused by sanding them to shape in a 28' radius spherical dish. The braces are glued to the top with the top supported by the 28' spherical dish. The top edge of the rims is profiled in a 28' radius cylindrical sanding dish. The top is then glued to the sides with the top resting on the cylindrical sanding dish and the sides clamped down into the top. What you end up with is the top being flat from the neck block to the tail block along the centerline.

One might think that fitting the top to the sides might involve some force but it doesn't. The difference between the spherical and cylindrical shapes at the tips of the bouts is minimal. The biggest difference is at the neck and tail ends. With the rims profiled cylindrically, the neck and tail ends of the top are not forced down into a dome shape and they are perfectly happy to be that way.

Here's a photo of the guitar I happen to be working on today showing that the top is flat along the centerline.

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Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter

Very cool J!

Laurent Brondel is another great builder using cylindrical tops with a relatively tight radius.
IIR, he drew a lot of his inspiration for his building style from Stefan Sobell who I think also uses a cylindrical top.

If you do a search over at the acoustic guitar forum you can find several Brondel build threads and searching the archives here and over there I pretty sure you can find threads where Laurent discusses his building philosophy and talks about his cylindrical tops.

I think, several years ago, he also posted both here and there (AGF) an experiment where he built two OM's simultaneously, one with his standard cylindrical top and one with a traditional Martin type domed top.