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Tucking braces C-Fox style?
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Author:  LanceK [ Thu Jul 05, 2007 11:54 pm ]
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I know that Paul Woolson does it this way, I believe he learned this process from Charles Fox. I was wondering, does anybody else do it like this?



I am VERY interested in this style, Its SO clean!
What are the "do's and dont's" How is this done?

Paul! I know your headed to Montreal, if you have a second, chime in!

Thanks!
Author:  David Collins [ Fri Jul 06, 2007 12:30 am ]
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It looks more like what I would have called "feathered" than "tucked". When I
refer to tucked braces I think of an end height of 1/16"-3/32" fit to a pocket
cut at the side. It looks like this is just very cleanly feathered down to a few
thousandths by the time it reaches the kerfing. This is what I used to do on
all tone bars and wing braces. Gibson did it for years on thier cheaper
unbound backs, though often not quite so clean.
Author:  GregG [ Fri Jul 06, 2007 1:52 am ]
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Lance,

This is what I do as well, I just feather the brace out to nearly nothing, just leaving a hint of brace with an upside down chisel...I don't know how many 1000/nds are left under the kerfing, but it isn't much. I also run the "nearly nothing" feathered section the full width of the kerfing, not sure if it really matters but that's what I do.

Cheers,
Greg
Author:  John Mayes [ Fri Jul 06, 2007 8:00 am ]
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here at McPherson we actually rout a slot (with a CNC of course) in the back
itself and the braces have a scoop at the end that are level with the slot
depth and so no tapering or tucking is needed... does scare me though if a
brace comes loose good luck trying to glue it back down....
Author:  Doug O [ Fri Jul 06, 2007 8:16 am ]
Post subject: 

Lance,


Charles tapers the braces on the back as shown in the picture - leaving it only a few thousandths thick - relying on compression to make the fit.  He said he does it this way on the back for cosmetic reasons.  On the top bracing he tapers the braces to nothing, leaving them short of the lining - not tucked at all.  I asked him if he ever had problems with braces coming loose, and he said he's been doing it this way for over 30 years and has never had a problem.
Author:  John How [ Fri Jul 06, 2007 8:23 am ]
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I have just start doing that on to my back braces on the last several guitars. I've done that right along on the top braces except forward of the sound hole.

I fit the back to the sides while still in the form and mark the intersection and then carefully feather the brace to that point. If you get it real close, the linign will compress and look clean. You are the master of clean brace to lining fits so you shouldn't have any problem.
Author:  Greg [ Fri Jul 06, 2007 12:16 pm ]
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I've been "feathering" but not for ay good reason. Perhaps if I could cut anotch in the linings with better accuracy? Any way feathering seems to work.
Author:  Jon L. Nixon [ Sat Jul 07, 2007 1:09 am ]
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Everyone knows that cleanly notched linings are the hallmark of a skilled luthier, right up there with mitered purflings and the like. Show me your guitar, and I will pretend to be carefully examining your label when I am really just checking out how well you did the job......
Author:  Rick Turner [ Sat Jul 07, 2007 3:19 am ]
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I have a completely different approach. We cut out the kerfing completely at the ends of back braces, run the back braces to within about 1/16 of the side leaving them about 1/4" tall, and then put pillars on them glued to the sides. The back braces are rectangular in cross section and they're topped with .022" carbon fiber unidirectional strips.   The braces simply will not come loose, and on the first guitar I made like this, I was able to stand on the back before I glued the top on. My main concern is structural here, and this approach takes care of that issue quite well.   Aesthetically it looks entirely deliberate, and thus I think it's fine.   We do use Charles' design reverse kerfing.

For tops we taper bracing out to nothing at all to make the compliant edge of the top consistent all the way around.
Author:  old man [ Sat Jul 07, 2007 4:03 am ]
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Rick, do you have a pic of that?

Ron
Author:  Rick Turner [ Sat Jul 07, 2007 7:15 am ]
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The best pictures I have of it will be published in a few months in Fretboard Journal in a photo essay on how we build.   The photos are copyrighted, and I don't want to violate that.   I'll try to get some shots of my next build, though, and post them.
Author:  Pwoolson [ Mon Jul 09, 2007 7:35 am ]
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Lance, sorry for the late response, I just rolled in from Montreal.
To your questions of do's and don'ts:
Do feather them to exactly zero at exactly the lining. (Trust me, it's easier said than done)
Don't be tempted to leave them a little thick and chop off the ends right at the linings. You'll pop a brace very quickly that way.
In hindsight, it's actually harder to learn than notching the linings. I did one with notched linings once (about my 5th guitar) and it was easier than stopping short at that time. For me now, it's second nature so it not so bad.
Author:  KiwiCraig [ Mon Jul 09, 2007 11:06 am ]
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[QUOTE=Rick Turner] The back braces are rectangular in cross section and they're topped with .022" carbon fiber unidirectional strips.     [/QUOTE]

Rick, I realise you can't post pics at this time , but could you explain what you mean by unidirectional strips?
Author:  Pwoolson [ Mon Jul 09, 2007 1:01 pm ]
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And top. I don't inlet the top braces at all either. You'll find that it frees up about 1-2" around the perimeter of the guitar.

[QUOTE=Hesh1956] Paul I like this technique too and look forward to trying it. But I am wondering what perhaps may be obvious to some - what is the purpose of not inletting the back braces, a more lively, resonant back? Thanks.[/QUOTE]
Author:  L. Presnall [ Mon Jul 09, 2007 1:11 pm ]
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[QUOTE=LanceK]
I am VERY interested in this style, Its SO clean!
What are the "do's and dont's" How is this done?

Thanks![/QUOTE]

Lance, for your work to get any cleaner, you'd have to work in a sterile suit!
Author:  L. Presnall [ Mon Jul 09, 2007 1:16 pm ]
Post subject: 
[QUOTE=John Mayes] here at McPherson we actually rout a slot (with a CNC of course) in the back
itself and the braces have a scoop at the end that are level with the slot
depth and so no tapering or tucking is needed... does scare me though if a
brace comes loose good luck trying to glue it back down....[/QUOTE]

Dude! "Here at McPherson "WE"...THAT'S SO COOL!! WE! I can't believe I know a dude who actually works a living making McPhersons!!!!! You are still my hero!!! Now, smuggle out some o' those trade secrets and get 'em on the OLF!!! How's Wisconsin? Have you toured the Point Brewery yet?

Author:  Rick Turner [ Mon Jul 09, 2007 1:35 pm ]
Post subject: 
Unidirectional graphite composites have the fibers aligned in one axis only. Check www.graphitestore.com for materials that our pals at Los Alamos don't sell. I use both suppliers depending on what I need.

With just the back strip reinforcement glued in place (with the graphite top lamination) the back holds pretty close to the dished form in the vertical direction, and the strength is pretty impressive.   Add the graphite topped back braces and you've got a back that I, at about 168 lbs., can stand on with the back glued to the sides. So if your guitar building style is to make a rigid back, this is one way to do it. It's not the only way to go, but I believe it makes for great sonic projection.
Author:  John Mayes [ Mon Jul 09, 2007 2:17 pm ]
Post subject: 
[QUOTE=L. Presnall] [QUOTE=John Mayes] here at McPherson we actually
rout a slot (with a CNC of course) in the back
itself and the braces have a scoop at the end that are level with the slot
depth and so no tapering or tucking is needed... does scare me though if
a
brace comes loose good luck trying to glue it back down....[/QUOTE]

Dude! "Here at McPherson "WE"...THAT'S SO COOL!! WE! I can't believe I
know a dude who actually works a living making McPhersons!!!!! You
are still my hero!!! Now, smuggle out some o' those trade secrets and get
'em on the OLF!!! How's Wisconsin? Have you toured the Point Brewery
yet?

[/QUOTE]

haha.. No huge trade secrets here at McPherson. Some very different
approaches to building and design, but nothing completely nuts. Most of
it you could see openly during a factory tour.

Point Brewery? Is that the one in LaCrosse with the worlds largest six
pack?
Author:  L. Presnall [ Mon Jul 09, 2007 2:38 pm ]
Post subject: 
I think it was in the Stevens Point/Wausau area...it was years ago in the turboprop days...oh, wait...
Author:  Jim Watts [ Mon Jul 09, 2007 4:21 pm ]
Post subject: 
Hey Rick,
Check this out! It was my first guitar back in 95 or so.
The braces are nomex honeycomb with unidirectional carbon fiber top skins. It's over braced for sure but it's certainly not a dud. I often wonder why I haven't pursued this deeper.
Maybe I'll get back to it some time.


Quite a bit off the original topic, sorry bout that.
Author:  Rick Turner [ Tue Jul 10, 2007 3:36 pm ]
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Jim, very interesting, to say the least! That sucker has to be incredibly stiff across that "X". That's pretty much what I'm doing on back braces except they're spruce and CF.
Author:  Jim Watts [ Tue Jul 10, 2007 4:19 pm ]
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It'll compete with any helicopter on the planet! (many helicopter blades are the same construction)
I think there's something here but not in this exact configuration. Maybe I'll try it on the back sometime like you do, if you don't mind.
Author:  Rick Turner [ Tue Jul 10, 2007 4:22 pm ]
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Jim, if I minded, I wouldn't talk about it all!   

There's some proprietary stuff I'm working on for which I may apply for patent protection, but this isn't it.
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