Finally starting to brace my first build

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Kevin Sjostrand
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Joined: Sat Feb 09, 2008 8:06 pm
Location: Visalia, CA

Re: Finally starting to brace my first build

Post by Kevin Sjostrand »

Neil,
I've been using maple for the bridge plate, but on my last one I used Macauaba (Macawood) and the guitar sounds awesome....probably all due to the plate, NOT. It is a rosewood. If you want some, I can send you a piece, but I imagine any other rosewood will work fine, or just use maple.

Kevin
nkwak
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Joined: Sat Nov 13, 2010 9:55 pm
Location: Pittsburgh PA suburbs

Re: Finally starting to brace my first build

Post by nkwak »

OK, it's nearly time to give my bracing another go. As you recall the first attempt didn't go so well and they had to come off. This time I'm going to do something a little different:

Image

The new X bracing has been pre-cut with a lap joint of 100° which is wider than the original plans. I'm also not going to taper the upper transverse brace at all. Instead I'm going to have it butt up against the inside face of the sides. A couple of friends who are into Ervin Somogyi suggested I try it. The different angle means that I have to rethink where to put the lower face braces which I've already rough cut per the plans.

Another issue is how to address the way the finger braces and tone bars are to intersect the X braces. I'm going to try to cut housings in the underside of the X which has already been radiused to 28' arc. I've sharpened my 1/4" chisel and have been practicing on some soft wood scrap in my basement in anticipation.

As for procedure, I'm thinking of following the Cumpiano/Natelson process where the X goes on last. I'm going to keep everything but the X braces flat on the bottom and use clamps instead of the go-bar deck. I just don't trust that contraption, but I guess I'll have to when it comes time to glue up the X again.

Since bending the sides this will be the most exciting part. Tonight I hope to finish radiusing the back rims then I'm moving on the top. Wish me luck!
~ Neil
nkwak
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Re: Finally starting to brace my first build

Post by nkwak »

I got started on the soundboard bracing last night:

Image

I opted to do the upper transverse brace first and then move on to the finger braces instead of the X braces because they both do not follow the 28' radius. I'd have done the lower face braces too but I ran out of go-bars. They won't have a radius underneath either so I won't break out the radius dish until I've shaped the edges that will intersect with the X. I'm still going to cut housings in the X braces for them. Lastly will be the bridge plate, which I spent most of my time last night preparing. It's not quite ready yet either.

BTW, I'm really not a big fan of these go bars. A few slipped off and dinged the top. I know, don't blame the tool blame the operator but IMO I should have just used clamps as illustrated in Cumpiano/Natelson's book.
~ Neil
Jim_H
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Location: Bothell, WA USA

Re: Finally starting to brace my first build

Post by Jim_H »

I use those same go bars for some things, and I agree, they can be difficult. One thing I learned is that you don't need a ton of deflection. It only makes them harder to manage and increases the potential for them to slip off.

I did some testing using a small digital scale and various lengths of fiberglass rod, and found out that increasing the deflection of the bar doesn't significantly increase the clamping pressure.

Also, the black tips are a compromise. Because they are a bit soft, it can contribute to the end of the bar creeping off the side of a brace. The obvious benefit is that when it does slip off, it hopefully wont do as much damage.

Lastly, the go bar deck is just another tool. Just like a chisel or a router, or even a camp clamp, it takes time and experience to develop proficiency and get comfortable with their idiosyncrasies.
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David L
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Re: Finally starting to brace my first build

Post by David L »

I am a big fan of the gobar deck. On the one top and back that I have braced up I had very little slippage (only 1 or 2) and I contoured my braces prior to glueing (the tops of the braces are rounded over), don't know if it's because I was very careful to center the tip of the rod on the brace or just beginner's luck. All of my rods have the black tips on them and the deflection of the rods was about the same as in your picture.

David L
kencierp

Re: Finally starting to brace my first build

Post by kencierp »

As many know I am not a fan of the go bar deck. However the best one I built was very, very sturdy (triple thickness top) 36" tall. I used Willow and/or Ash (actually any wood will work) bars about 5/8" wide 5/16 thick. I found that the one size fits all idea did not work for me (seldom does for any process) So I had different length bars and used a color coded pattern/layout and also color coded the bars to match the application. $.02
tippie53
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Re: Finally starting to brace my first build

Post by tippie53 »

I to am a fan of go decks but I did use so many different woods for the sticks. I found Fiberglass the best product for that . The best method for clamping without a doubt is vacuum . I use both but find the go bar more accessible especially with using HHG .
It comes down to preference and technique. As you know Ken and I get good results with different methods . There are more than one way to do things.
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Darryl Young
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Re: Finally starting to brace my first build

Post by Darryl Young »

I'm a big fan of a go-bar deck. I made mine so I can adjust the height of the top deck. I don't flex the go-bars as far as is shown in the pics. Probably the most pressure is produced when the go-bars are barely flexed. The further you flex them, the more stored energy you have waiting to do damage. I used threaded rod for the corner posts so it's easy to raise the upper deck so the rods are flexed less. Easier than stocking bars of different lengths.
Slacker......
David L
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Re: Finally starting to brace my first build

Post by David L »

Darryl Young wrote:I'm a big fan of a go-bar deck. I made mine so I can adjust the height of the top deck. I don't flex the go-bars as far as is shown in the pics. Probably the most pressure is produced when the go-bars are barely flexed. The further you flex them, the more stored energy you have waiting to do damage. I used threaded rod for the corner posts so it's easy to raise the upper deck so the rods are flexed less. Easier than stocking bars of different lengths.
I also use threaded rods so that I can adjust the height to do different operations such as bracing up the top and back, make an adjustment and I'm good for closing the box.

David L
Darryl Young
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Joined: Fri Jul 30, 2010 6:44 pm
Location: Arkansas

Re: Finally starting to brace my first build

Post by Darryl Young »

David L wrote:
Darryl Young wrote:I'm a big fan of a go-bar deck. I made mine so I can adjust the height of the top deck. I don't flex the go-bars as far as is shown in the pics. Probably the most pressure is produced when the go-bars are barely flexed. The further you flex them, the more stored energy you have waiting to do damage. I used threaded rod for the corner posts so it's easy to raise the upper deck so the rods are flexed less. Easier than stocking bars of different lengths.
I also use threaded rods so that I can adjust the height to do different operations such as bracing up the top and back, make an adjustment and I'm good for closing the box.

David L
Yep, one of the reasons I like it so much! I can also put the radius dish under the rim while the rim is still in the mold to glue the top/back. Works great and holds everything just right.
Slacker......
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