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The Torres Cardboard Guitar
http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=17618
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Author:  Pat Foster [ Thu Jun 26, 2008 3:01 pm ]
Post subject:  Re: The Torres Cardboard Guitar

David,

This is very interesting to me. Thanks for posting it.

Author:  Jim Kirby [ Thu Jun 26, 2008 4:40 pm ]
Post subject:  Re: The Torres Cardboard Guitar

David - Why is the back center strip needed? Do you have a sense that it is structural?

Jim

Author:  David LaPlante [ Thu Jun 26, 2008 6:51 pm ]
Post subject:  Re: The Torres Cardboard Guitar

Yes Jim I think so.
The original has this and I'll include it in order to be as faithful as I can to the original design.
The cardboard has the same stiffness in all directions thus the usual extra strength one would have along the grain of the back is not there.
I think this is what was behind the thicker and stiffer back reinforcement strip.

Author:  David LaPlante [ Thu Jun 26, 2008 11:42 pm ]
Post subject:  Re: The Torres Cardboard Guitar

Top bracing is now complete.
Attachment:
CardboardTorresVI 001.jpg

Attachment:
CardboardTorresVI 003.jpg

The unusual cut off braces (as far as I know) are unique on a Torres guitar.........these would make more sense if they were a later addition.
Attachment:
CardboardTorresVI 004.jpg

The rosette installed.
Attachment:
CardboardTorresVI 002.jpg

The first step in "free assembly" is to align and glue the neck to the top as well as the end block.
Attachment:
CardboardTorresVI 005.jpg

Attachment:
CardboardTorresVI 006.jpg

Author:  Jim Kirby [ Fri Jun 27, 2008 5:54 am ]
Post subject:  Re: The Torres Cardboard Guitar

David LaPlante wrote:
Yes Jim I think so.
The original has this and I'll include it in order to be as faithful as I can to the original design.
The cardboard has the same stiffness in all directions thus the usual extra strength one would have along the grain of the back is not there.
I think this is what was behind the thicker and stiffer back reinforcement strip.


Aside from the question of historical accuracy, it looks like a very good candidate for an X-braced back, to pick up the extra stiffness along the back.

Jim

Author:  David LaPlante [ Fri Jun 27, 2008 2:00 pm ]
Post subject:  Re: The Torres Cardboard Guitar

Continuing with the "free assembly process"
The sides are aligned with the penciled tracing of the pattern on the inside of the top and glued to the neck and end blocks.
Attachment:
CardboardTorresVII 001.jpg

No glue is used along the edges where the sides meet the top, glue blocks (peonies) are installed to attach it at this juncture.
Attachment:
CardboardTorresVII 003.jpg

Attachment:
CardboardTorresVII 004.jpg

Author:  David LaPlante [ Fri Jun 27, 2008 8:12 pm ]
Post subject:  Re: The Torres Cardboard Guitar

Here is the rather stiff center support being glued that Jim Kirby and I were discussing. It's about twice as thick as a normal one and the grain is longitudinal so it adds a lot of support to the back.
Attachment:
CardboardTorresVII 002.jpg

Author:  David LaPlante [ Sat Jun 28, 2008 2:00 pm ]
Post subject:  Re: The Torres Cardboard Guitar

One observation to share is that the more complete the structure gets, the closer it feels to being made of regular materials. I expect that it will feel and weigh what a typical guitar would.
Attachment:
CardboardTorresVIII 001.jpg

Attachment:
CardboardTorresVIII 004.jpg

The reinforcement strip shown previously has stiffened the back plate up nicely. Here is the bracing being glued.
Attachment:
CardboardTorresVIII 003.jpg

I'm notching the bracing over the strip to maintain as much support as possible.
Attachment:
CardboardTorresVIII 002.jpg

Author:  Sam Price [ Sat Jun 28, 2008 3:15 pm ]
Post subject:  Re: The Torres Cardboard Guitar

Thank you for the updates, this is a very informative thread!

Author:  Alexandru Marian [ Sat Jun 28, 2008 5:54 pm ]
Post subject:  Re: The Torres Cardboard Guitar

Funny that when I was reading the initial discussion on the back cedar strips, I was thinking that if I was to build a cardboard guitar I would use a pair of solid cedar strips (mimicking a 3 piece back) and notch the spruce bars over. Then i decided not to post it because well, it wasn't me building :)

Author:  David LaPlante [ Sat Jun 28, 2008 6:53 pm ]
Post subject:  Re: The Torres Cardboard Guitar

Alex, according to Joan Pellise' there are actually three in the original. However, Joshua French observed that the outer two are later additions. I've just put the main center one in as I used a slightly heavier board. I also could see its shape in the photos.

Author:  Jim Kirby [ Sat Jun 28, 2008 9:01 pm ]
Post subject:  Re: The Torres Cardboard Guitar

This is starting to get really compelling. I can't think of any vaguely interested person who wouldn't be astounded if you pulled one of these out to show to them. I know the original sounds good, and can't wait to see how your does. A similar one may be next on the list here.

Thanks for all the discussion of the back brace.

Author:  David LaPlante [ Sun Jun 29, 2008 12:41 pm ]
Post subject:  Re: The Torres Cardboard Guitar

The linings are now in (kerfed Spruce) as well as the "long" rib blocks to support the harmonic bars.
Attachment:
CardboardTorresIX 001.jpg

The back is ready to be fitted and glued. The back braces will also get shorter "rib blocks".
Attachment:
CardboardTorresIX 002.jpg

Author:  ChiyoDad [ Sun Jun 29, 2008 2:30 pm ]
Post subject:  Re: The Torres Cardboard Guitar

This is quite exciting. :D

I'm looking forward to the finished results.

Author:  senunkan [ Sun Jun 29, 2008 10:00 pm ]
Post subject:  Re: The Torres Cardboard Guitar

Hi David,

This is definitely getting more and more interesting and exciting.
I have one question regarding the stiffness of the sides.
(Before and after closing)
Would it be able to withstand the weight of the player's arm resting on the lower bout?
Is there any deformation of any sort?

Sen

Author:  David LaPlante [ Mon Jun 30, 2008 10:59 am ]
Post subject:  Re: The Torres Cardboard Guitar

No problem in that regard. I've used a somewhat thicker material for the rims than on the original. As a result, I've left out the later added reinforcements and have a nice resilient structure.
Here is the back being glued.
Attachment:
CardboardTorresX.jpg

Author:  Steve Kinnaird [ Mon Jun 30, 2008 12:20 pm ]
Post subject:  Re: The Torres Cardboard Guitar

Ooooh, ^ that would make me a bit nervous!

Looking great David.
Many thanks!

Steve

Author:  Dave White [ Mon Jun 30, 2008 12:31 pm ]
Post subject:  Re: The Torres Cardboard Guitar

David,

This is a fascinating project that I am really enjoying following and I will be interested to see how it plays and sounds when finished.

Is this one where a future repair could be "papering over the cracks"? Sorry . . . I couldn't resist that one.

Author:  WaddyThomson [ Mon Jun 30, 2008 1:19 pm ]
Post subject:  Re: The Torres Cardboard Guitar

Dave, this is the one that you just crumple up and toss in the recycle bin if you don't like the sound! :D

Author:  David LaPlante [ Mon Jun 30, 2008 2:03 pm ]
Post subject:  Re: The Torres Cardboard Guitar

OK, Out of the clamps, flush trimmed (I went to the store and picked up a new Freud bit to get the cleanest cut I could) and cut for bindings.
Attachment:
CardboardTorresXI 001.jpg

Attachment:
CardboardTorresXI 002.jpg


A relatively new bit from LMI produced pretty clean results. I had to be careful to "back in" to the cut all the way around as the cardboard will tend to deflect and bunch up in front of the bit.
Attachment:
CardboardTorresXI 003.jpg

Attachment:
CardboardTorresXI 004.jpg


At this point, the less I try to fool with the surface the better. I've pre sanded my rosewood bindings and beside a little rounding over at the edge, I'll pretty much
have to live with the fit I get out of the gate. The top can be handled in the usual way, but the back and sides
will have to forego any scraping or sanding.

Author:  David LaPlante [ Tue Jul 01, 2008 8:08 pm ]
Post subject:  Re: The Torres Cardboard Guitar

Back Bindings are now in.
Attachment:
CardboardTorresXII 003.jpg

Attachment:
CardboardTorresXII 004.jpg

The preliminary carving of the heel has been done plus the fret board and bridge are under way.
Attachment:
CardboardTorresXII 002.jpg

Next, the top binding and purflings go in.
Attachment:
CardboardTorresXII 001.jpg

Author:  cmacksam [ Wed Jul 02, 2008 4:24 pm ]
Post subject:  Re: The Torres Cardboard Guitar

Mike Collins wrote:
Dave ;
is that Brazilian poster board? oops_sign

No, Mike, it's obviously Manila. ;)

Interesting project, Dave. Strange....but interesting. I admire your sense of adventure! [:Y:]

Author:  Pat Foster [ Wed Jul 02, 2008 4:41 pm ]
Post subject:  Re: The Torres Cardboard Guitar

Carlton!!! Great to see you here again!!!!

Pat

Author:  Darrin D Oilar [ Wed Jul 02, 2008 4:41 pm ]
Post subject:  Re: The Torres Cardboard Guitar

I can remember as a kid telling my dad that I could easily build a guitar. I remember having this image of a shoe box, with a wrapping paper roll stuck in one end and some strings across the whole thing. Now I know i was wrong to go with the wrapping paper tube. :D

Seriously, this is a fascinating thread. I can't believe how fast you work though. Sheesh. Something tells me this isn't your first rodeo.

Darrin

Author:  David LaPlante [ Thu Jul 03, 2008 12:17 pm ]
Post subject:  Re: The Torres Cardboard Guitar

Here is the top binding in with the cloth tape wrapped to secure it as the glue (fish) dries.
Attachment:
CardboardTorresXIII 001.jpg

Now trimmed flush with the surface of the top. As this point I can evaluate whether I got the plantilla right.
Attachment:
CardboardTorresXIII 003.jpg


Detail of the binding and rosette.
Attachment:
CardboardTorresXIII 002.jpg

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