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More bracing discussion
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Author:  John Hale [ Thu Jul 03, 2008 5:21 am ]
Post subject:  More bracing discussion
Hi I'm soon to start the bracing for my first guitar, I'm following Kinkheads design, but using the Cumpiano bolt on neck. My questions are

1. Does every brace need a seperate template? Or could you use one template for the say all the top braces and another for all the back braces? I've seen a video on youtube where that's what's done

2. Can someone further explain the use of cauls, because then every brace would need a seperate caul a different radius from the brace it was clamping minus the thickness of the plate that was being clamped. Or as I was thinking could I use a strip if pine moulding that was sturdy but still flexible

3. Scalloped bracing v Parobolic Bracing (help I'm confused)

Thanks

John
Author:  Jim Kirby [ Thu Jul 03, 2008 6:33 am ]
Post subject:  Re: More bracing discussion
Hi John, I'll bite since no-one else is here yet. (I'm no expert though).

JJH wrote:
Hi I'm soon to start the bracing for my first guitar, I'm following Kinkheads design, but using the Cumpiano bolt on neck. My questions are

1. Does every brace need a seperate template? Or could you use one template for the say all the top braces and another for all the back braces? I've seen a video on youtube where that's what's done

2. Can someone further explain the use of cauls, because then every brace would need a seperate caul a different radius from the brace it was clamping minus the thickness of the plate that was being clamped. Or as I was thinking could I use a strip if pine moulding that was sturdy but still flexible

3. Scalloped bracing v Parobolic Bracing (help I'm confused)

Thanks

John


(1) Are you thinking about separate templates because you want to do the brace close to final shape before gluing? If so, then I guess you do need some sort of guide, at least rough, for shaping each brace. Some people make up a set of braces that are shaped but not tapered (i.e., still rectangular in cross section) and then use these to mark subsequent brace blanks.

I prefer to just radius the brace blank's bottom and glue it to the plate unshaped, and do all the shaping afterwords.

(2) you don't really need cauls for gluing braces, although they can arguably help distribute the clamping force. Closely spaced go bars (if using a go bar deck), or get enough cam clamps that you can get a bunch on each brace as you are gluing. A go-bar deck is worth having and simple to set up - search the archives.

(3) We're not supposed to discuss religion here :o Just kidding. Scalloped vs. parabolic is in the ear of the beholder. Want that Martin sound? You should start with scalloped. Parabolic bracing is more fingerstyle-oriented. Now a bunch of really experienced people will add that you can build to the tone you want with pretty much any system.

Jim
Author:  Jody [ Thu Jul 03, 2008 7:42 am ]
Post subject:  Re: More bracing discussion
John , templates are a good idea, if you like the way your first turns out , templates will help you duplicate that more easily on number two.
Just pick a brace design and go with it, a good sounding guitar can be made with either scalloped or tapered bracing , just pick one " school " and stick to it on your first . Jody
Author:  Hesh [ Thu Jul 03, 2008 7:43 am ]
Post subject:  Re: More bracing discussion
John buddy I am not sure that I understand your question regarding templates. Are the templates to be used as a guide for individual brace shapes or are the templates to be used for brace location lay-out?

As for cauls, presumably gluing cauls - most folks use a go-bar deck with radius dishes for brace glue-ups. In addition the braces, at least mine, are only radiused on the bottom prior to gluing and then carved to the shapes that I want and the top or back is telling me that it needs after they are glued in place. See the picture below.

Attachment:
DSC01512.jpg


As for parabolic vs. scalloped if we drop the "vs." from our thinking and discourse we will realize that we are simply describing two different brace shapes. Not necessarily an opposing bracing philosophy. I don't agree that any discussion of bracing "styles" needs to be considered religion either in as much as many of us will use at least these two styles or anything else that may be a good idea going forward.

There are indeed some differences in tone between the two styles but these differences, if one wishes, can be minimized or exaggerated - it's all up to what the builder is attempting to accomplish.

You might want to start another thread if you want to get into the different bracing styles and let this thread simply address your template and caul questions - in the past bracing threads can get pretty long.
Author:  John Hale [ Thu Jul 03, 2008 8:36 am ]
Post subject:  Re: More bracing discussion
Cheers guys what I mean about templates is for the back if I number the braces 1-4 top to bottom from my head these figures are not actual ones brace templats need for brace:

1. 3/32" over 11"
2. 7/64" over 10 13/16"
3. 3/16" over 14 1/2"
4. 1/8" over 14 5/16"

each a slightly different radius I worked out the actual radii a while so each would need a different radius template to shape the bottoms.

Thanks guys bent 2 practice sides in cherry, off to do the real things in mahogany now.
Author:  John Hale [ Thu Jul 03, 2008 10:06 am ]
Post subject:  Re: More bracing discussion
Todd I know about radius dishes etc but when I worked out the radii in CAD for the braces each radius from brace to brace varied that's why I mentioned differing templates
Author:  Barry Daniels [ Thu Jul 03, 2008 10:16 am ]
Post subject:  Re: More bracing discussion
You did something wrong in your figuring. Like previously said, the radius should stay constant.
Author:  stan thomison [ Thu Jul 03, 2008 10:42 am ]
Post subject:  Re: More bracing discussion
I do different than most here. I use vacuum to glue braces. I use cauls. I glue the bridge plate first (pre shaped with splay) I know where bridge is going , so drill holes in plate and top setting plate and caul on the top or gluing. I pretty much have braces shaped (not final by any means) so after bridge plate, I do the transverse brace. Then at one time X, tone bars, finger braces and braces around soundhole all at one time using cauls. Yes for most part I use templates for brace positions. There may be times I vary the angle of X so make those markings on the top as I go, but know ahead of what I am planning (don't want to make to much angle and mess up bridge stuff, been there done that) Boss just shook his head and said make it work now. I did, but wouldn't recommend it as a thing to do. My clamp system is so I can lay the braces in, and then lock them down some so don't move around.

I tried to talk Bill into this a few times when there, and he considered it, but decided he liked the "old go bars and they do just fine" Very true, but I always had some problems with them and so for me this is easier. Suggest making some templates. Makes your work more consistant getting started and saves time IMHO
Author:  John Hale [ Thu Jul 03, 2008 1:10 pm ]
Post subject:  Re: More bracing discussion
Thanks Todd that would explain it.

Don't know whether to start a nep thread, but now to parabolic or scalloped I'm neither for or against I'm a fingerpicker if that makes a difference and like a real bass to my tone. I'm building an OM, and my top is 0.110" it's 3rd quality swiss spruce so quite free and I'm tempted to leave the width of the sides wider. The back and sides are mahogany and are NOT bookmatched. I know its like asking if apples are better than oranges, but I'd like to know what system people think would be best in my situation.
Author:  Jim Kirby [ Thu Jul 03, 2008 1:19 pm ]
Post subject:  Re: More bracing discussion
John - Are you thinking of the difference between the brace radius if it lies in a plane parallel to the equatorial plane, or lies in a great circle plane? There is indeed a difference, and most of us ignore it when radiusing the braces and radius them to the great circle diameter, corresponding to our dish. Note though, that if you do final sanding of the brace in the dish, and sand it along a line that corresponds to its gluing position, you will end up making that minor adjustment automatically.
Author:  Alan Carruth [ Thu Jul 03, 2008 2:33 pm ]
Post subject:  Re: More bracing discussion
IMO, a tapered (or 'parabolic', if you must) brace profile works better for fingerstyle guitars, while rythm-oriented flat pickers tend to prefer scalloped. As with the 'art and science' threads, there really should not be a 'vs.' in there, nor is there any religion involved, although some folks get pretty zealous about their particular system. As you get more experience, and understand on some level how the guitar works, you'll figure out how to associate the bracing system with the sound you want to make.
Author:  Hesh [ Thu Jul 03, 2008 2:46 pm ]
Post subject:  Re: More bracing discussion
John buddy either parabolic (like) or scalloped braces can result in a great finger picking guitar. If you like more bass and even though a parabolic braced guitar can produce very good bass if this is one of your first guitars scalloped braces will probably produce more bass for you.

But...... those of us who brace in a more parabolic style usually learn how to milk more bass out of our guitars too.

Al summed it up well for me but I'll add some characteristics of a parabolicish :D braced guitar that I notice: The bass is very tight and not boomy and the trebles are fairly fat, well defined, and clear. It is the mid range that I really like the most where the notes are loud, fat, and warm. I would liken this to the electric equivalent of a Les Paul Standard played through a vintage valve amp. In addition IMHO paraboolicish braced guitars can sound pretty loud when you play up the neck where I notice more volume drop off with scallopedish braced guitars while playing up the neck.

Again I will use either style depending on the desired sound. Neither is better than the other they are simply different.

Al my friend do we have to call them "tapered" that brings visions of ........ well you know...... to mind..... :D
Author:  John Hale [ Thu Jul 03, 2008 4:58 pm ]
Post subject:  Re: More bracing discussion
So Hesh what your saying is parabolic is in genral better for the sound I desire, but harder to achieve so for a first I should use scalloped braces until I have gained more experiance?

Would you be willing to share your dimensions I've noticed Cumpiano uses tapered/prabolic braces on steel string and scalloped on nylon strings should I follow his lead or scallop is what I'm asking, and should I follow his dimensions or would you suggest lighter bracing.
Author:  Hesh [ Thu Jul 03, 2008 5:42 pm ]
Post subject:  Re: More bracing discussion
John not exactly - the sound that you are describing is something that can be achieved with either bracing style.

The reason that I believe that you would be better served to build your first with scalloped bracing is that dimensions for scalloped braces are available on a number of very good plans. I would always recommend that a first time builder build at least mostly around a proven plan.

My first parabolic braced guitar was built winging it and sure enough I over braced the sucker....... It's pretty common for newer builders to over brace but there are scalloped plans out there that are not over braced. There are no parabolic/tapered guitar plans available that I know of.

As for sharing my bracing dimensions with you - sure - my pleasure. I have done this many times on the OLF including the posting of lots of pictures of my bracing. Others who brace with a parabolic style also have posted pictures and provided dimensions.

Be aware though that my final brace dimensions are determined by what the guitar and the wood that I am working with tell me that they want to be. This means that not only your mileage may vary but that surely your wood will vary. But what I do will certainly get you close to where you want to go.

Let me know when you are ready to do your bracing and I will be very happy to tell you everything that I can.
Author:  John Hale [ Fri Jul 04, 2008 6:00 am ]
Post subject:  Re: More bracing discussion
Hi Hesh, Thanks for all the help and advice. Today I plan to make all the braces I intend to use a 15 foot radius for the back with braces 5/16" wide 21/32" tall. As for the top the x braces from what I've read should be 5/16" by 9/16" and slightly concave. The tone bars are 5/16" by 1/2" tall for the upper and 5/16" by 7/16" for the lower, finger vraces are 1/4" by 5/16 for the lower ones and 9/32" by 7/16 for the upper ones. Around the sound hole is standard amd the shoulder brace is 9/16" by 13/16" at the moment I'm not sure if I should add the popsicle brace and am chewing over if I should use the martin forward x bracing style as mentioned here. On my jumbo and dreadnoughts I use 14-58 strings dunno if that makes any difference.

Cheer Guys
Author:  John Hale [ Fri Jul 04, 2008 9:38 am ]
Post subject:  Re: More bracing discussion
Also just found this and explains some what what I wanted to know

viewtopic.php?f=10102&t=1018&hilit=+bracing
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