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  #16  
Old 09-22-2013, 12:04 PM
Steven Bollman Steven Bollman is offline
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Thanks for the comment. I spent some time doing exactly what you are talking about. I think "in person" it looks right. There is some distortion from the iPhone lens and color imbalance in the file that contribute to the slightly out of parallel grain that I think is what you are referring to.
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  #17  
Old 09-22-2013, 12:07 PM
Steven Bollman Steven Bollman is offline
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Thx Dru. The circle jig setup and testing took awhile. And I knew that I had to be patient. Inlaying and gluing the purfling went much faster than I expected and the fit was better than I expected. I also managed to not have any chip out that I can detect. So farine pleased. I'm very aware that the road is long and screw ups are lurking.
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  #18  
Old 09-22-2013, 12:34 PM
Howard Klepper Howard Klepper is offline
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Rex, I see a bottle of Titebond II "Premium" glue in your photos. Do not use it. The Original Titebond is a better glue for guitar making. It dries harder and creeps less.
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  #19  
Old 09-22-2013, 01:03 PM
Steven Bollman Steven Bollman is offline
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Quote:
Originally Posted by Howard Klepper View Post
Rex, I see a bottle of Titebond II "Premium" glue in your photos. Do not use it. The Original Titebond is a better glue for guitar making. It dries harder and creeps less.
WoW! Thx, Howard. I've read so many conflicting recommendations it's hard to know what to do. I have the original Titebond here as well. Since this is my first build, I am somewhat at the mercies of luck and good fortune. I appreciate your comment and experience.
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  #20  
Old 09-23-2013, 08:42 PM
Steven Bollman Steven Bollman is offline
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Working on the back strip today made of curly Koa and white and black maple strips.





Pretty shavings.



So far so good. Koa back strip planed and scraped flush.

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  #21  
Old 09-24-2013, 01:13 PM
Steven Bollman Steven Bollman is offline
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I received my Lutz spruce brace wood today. Now to figure out what to do with it. Any suggestions on splitting it?

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  #22  
Old 09-24-2013, 05:49 PM
Jim.S Jim.S is offline
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Morning Rex, you can split with a chisel or knife by splitting in half then half again etc. By the look of it though they look like they either have a split edge or have been sawn from a split edge so you could just re-saw them instead of splitting. Minimising runout is your aim.

Jim
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  #23  
Old 09-24-2013, 11:37 PM
Steven Bollman Steven Bollman is offline
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Originally Posted by Jim.S View Post
Morning Rex, you can split with a chisel or knife by splitting in half then half again etc. By the look of it though they look like they either have a split edge or have been sawn from a split edge so you could just re-saw them instead of splitting. Minimising runout is your aim.

Jim
Thanks Jim! I appreciate that insight.
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  #24  
Old 09-24-2013, 11:42 PM
Steven Bollman Steven Bollman is offline
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I'm starting to think about the radius dish. I had an incredibly interesting/useful conversation with Tracy at Luthier Supplier. What I've been able to understand about the Stahl Style 6 design is the braces are glued up under tension (I learned that from American Lutherie magazine (issue 112). So in that issue the radii are stated as 12' across the top and 10' across the bottom. But since its glued under tension there will be some spring back when it comes out of the dish. Getting a dish with a 7-8' radius is unlikely so I had an idea about making a skeleton dish out of baltic birch plywood. It would go into the go bar deck to glue the braces to the front and back sound boards. I know the proportions are inaccurate in my drawing, but it is just meant to convey an idea. Does it seem like this would work?

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  #25  
Old 09-25-2013, 06:48 AM
charles Tauber charles Tauber is offline
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For what did you want to use the dish?

If it is solely for gluing back braces on a single back, it is over-kill. There are numerous simpler ways to accomplish that.
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  #26  
Old 09-25-2013, 10:08 AM
Ned Milburn Ned Milburn is offline
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Quote:
Originally Posted by Rex Tremende View Post
I received my Lutz spruce brace wood today. Now to figure out what to do with it. Any suggestions on splitting it?
Did you get your wood from Shane in BC?? He supplies Lutz, and if it was from him it is likely that you can adjust your bandsaw for the tilt of the grain and then rip. You should be able to see if the grain lines follow the edges or not. If they are off, then split once then line up the split face to your bandsaw fence.

You could do the same thing with a table saw if you prefer. I find the bandsaw much more friendly.
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  #27  
Old 09-25-2013, 10:20 AM
Steven Bollman Steven Bollman is offline
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Quote:
Originally Posted by charles Tauber View Post
For what did you want to use the dish?

If it is solely for gluing back braces on a single back, it is over-kill. There are numerous simpler ways to accomplish that.
Hi Charles, thanks for your comment. The design calls for a 12' radius across the top and a 10' radius on the back glued up under tension. I thought a dish was the way to go. The smallest radius dish that I have sourced is 12'. So, I'm trying to find a way to accomplish what the design calls for. I don't know if I'll build another, so I don't want to spend a couple of hundred bucks on dishes that I won't use again. I would love to know about other solutions.
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  #28  
Old 09-25-2013, 11:14 AM
charles Tauber charles Tauber is offline
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Quote:
Originally Posted by Rex Tremende View Post
a 10' radius on the back glued up under tension.
There are several ways to interpret what you mean by "under tension" and the construction methods to use depend on that.

Is the gluing surface of the braces straight, but being glued to the back while forced into the desired radius? Are the braces and back then released after gluing, allowing them to do their own thing, or is the forced curvature maintained until after assembly is complete?

Also, by "10' radius" do you mean a truly spherical curvature? that is, 10' along the length of the back as well as across its width? Or can a non-spherical shape be used?

Methods to use depend upon what, exactly, you want to achieve. Keep in mind that spherical dishes are a quite recent development in guitar making. More than likely, the original didn't have a spherical curvature, top or back.
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  #29  
Old 09-25-2013, 11:57 AM
Steven Bollman Steven Bollman is offline
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Quote:
Originally Posted by charles Tauber View Post
There are several ways to interpret what you mean by "under tension" and the construction methods to use depend on that.

Is the gluing surface of the braces straight, but being glued to the back while forced into the desired radius? Are the braces and back then released after gluing, allowing them to do their own thing, or is the forced curvature maintained until after assembly is complete?

Also, by "10' radius" do you mean a truly spherical curvature? that is, 10' along the length of the back as well as across its width? Or can a non-spherical shape be used?

Methods to use depend upon what, exactly, you want to achieve. Keep in mind that spherical dishes are a quite recent development in guitar making. More than likely, the original didn't have a spherical curvature, top or back.
Wow, all good questions. I don't have all the answers. I'm sure you're correct about this design from the 1920's not using a dish. I believe the gluing surfaces of the braces were intended to be straight. and forced into shape under pressure. I'm still researching it and haven't found much on it yet.
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  #30  
Old 09-25-2013, 12:15 PM
arie arie is offline
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Quote:
Originally Posted by Rex Tremende View Post
I'm starting to think about the radius dish. I had an incredibly interesting/useful conversation with Tracy at Luthier Supplier. What I've been able to understand about the Stahl Style 6 design is the braces are glued up under tension (I learned that from American Lutherie magazine (issue 112). So in that issue the radii are stated as 12' across the top and 10' across the bottom. But since its glued under tension there will be some spring back when it comes out of the dish. Getting a dish with a 7-8' radius is unlikely so I had an idea about making a skeleton dish out of baltic birch plywood. It would go into the go bar deck to glue the braces to the front and back sound boards. I know the proportions are inaccurate in my drawing, but it is just meant to convey an idea. Does it seem like this would work?
first shape the braces as you want. then use a compression pad under the back to force the plate to conform to your brace radii when gluing. you can use a go-bar deck or bessy clamps and runners -what ever works. easy to do. on my first i used a nice fluffy bath mat (new of course). the result is a back that is "built under tension"
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