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Need input on "Go-Bar" clamping system
http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=26880		 Page 1 of 1
Author:  Dave_E [ Wed Apr 07, 2010 11:15 am ]
Post subject:  Need input on "Go-Bar" clamping system
Hi All,

This OM I'm building is turning out best I've ever done so far, and as I move along further in my luthier hobby, I find myself "investing" in more technical (sometimes correct) tooling to do a better job. I'm considering a Go-Bar clamping system, disks, and sanding disks for the rims. A question I have for the deck system is this; if you glue your radiused braces on first, then your flat bracing up front, it would seem to me that you would have to set your top on a flat surface to glue the flat braces, correct?

Second question; do you radius your top rim completely even though the front end wants to be flat? In the past I've just used a radius stick and worked the back half of the top rim. I've built 10 guitars without these special tools, but I'll be honest, there were times when I struggled to get the final outcome correct or maybe just close, and I read articles and look at pictures thinking "this would help"! As always thanks for sharing! [:Y:]

Dave
Author:  Fred Tellier [ Wed Apr 07, 2010 11:17 am ]
Post subject:  Re: Need input on "Go-Bar" clamping system
Yes for both questions in my way of building.

Fred
Author:  Hesh [ Wed Apr 07, 2010 11:51 am ]
Post subject:  Re: Need input on "Go-Bar" clamping system
Dave as Fred said yes to both questions. Although there are probably other ways to do these things this is how I do what you are asking about - flattening the upper bout: http://www.luthiersforum.com/forum/viewtopic.php?f=10117&t=25931

My sequence for gluing my braces is to glue all radiused braces first, carve, voice, etc. and then using a flat backing I glue in the upper transverse brace and the stinkin popsickle brace.... :)

Hope this helps buddy.
Author:  Mike Lindstrom [ Thu Apr 08, 2010 6:54 am ]
Post subject:  Re: Need input on "Go-Bar" clamping system
Interesting idea, Todd. I never thought about trying to do it that way. I always do the X first and am fighting it skating around on me. I'll have to give it a shot your way.

And to the OP - I do from the x down, in the dish. Above the X on a flat board. Oh. And the sound hole reinforcement in the dish.

mike
Author:  Colin S [ Thu Apr 08, 2010 7:08 am ]
Post subject:  Re: Need input on "Go-Bar" clamping system
I radius all of my braces including the UTB, done 40+ guitars this way, see no reason to change. However I do use a different neck/FB system and only need to very lightly flatten about 2 sq ins of the top with a sanding block when I attach the neck. Check my build thread here:

http://www.luthiercom.org/phpBB3/viewtopic.php?f=107&t=1261

Colin
Author:  truckjohn [ Thu Apr 08, 2010 7:49 am ]
Post subject:  Re: Need input on "Go-Bar" clamping system
You will find that there are as many ways of doing this as there are people building guitars...

If you want a flat UTB -- just glue a flat UTB on.. You can use a "Flat dish" -- aka piece of 3/4" particleboard....
Or.. you could just clamp the flat brace on with clamps like in the Cumpiano book....

Like several others here -- I have tried it both ways. Both work fine... Do which ever one you like best.

Another bit of info I found out the hard way... Go bar decks must support a tremendous amount of force. You need to take this into account when you build one.. How much force? I lifted a 300 lb office desk completely off the ground while clamping the top bracing on my Size 5 tenor last month... I had to add another 200 lbs of ballast to hold it down. (I was doing the Go-bar thing up under the desk.)

Figure this... Say 1 rod puts 20 lbs of force.... 10 rods = 200 lbs of up force... and 10 rods is barely enough to do anything... 20 rods = 400 lbs of force... which can put a serious hurt on structures that aren't designed for it.

But... They are super duper handy... so don't let this discourage you... just keep it in mind.

Thanks

John
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