Official Luthiers Forum!

This crossed my mind....what is the downside of eliminating the tailblock?

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Brad
Avon, OH

If you have an endpin jack - I wouldn't want to take a bash on the cable plug without a more substantial tailblock.

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The member formerly known as erikbojerik....

Brad,

Are you accounting for the taper before hand? Will you add extra linings now or use the hidden ones? What thickness are you using for your outer layer? It looks very cool!

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Burton
http://www.legeytinstruments.com
Brookline, MA.

Good point ...probaby a better question is how thick the tailblock section should be minimum?

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Brad
Avon, OH

Cool is almost an understatement!
Nice work and tutorial, Brad!

Thanks for sharing this, Brad.

I've been planning on nomex-cored sides for my next, but I hadn't thought of putting the linings on the inside. Great idea!

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-Clint Beacock

I accounted for the taper before I glued the linings to the inner side. No additional linings are needed just the inner linings. I used .025 for the inner side and .060 for the outer side.

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Brad
Avon, OH

That is actually pretty cool.I wonder if it will have any effect on sound?
James

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James W Bolan
Nashville Tennessee

I'll bet that butt end with the birch ply sandwiched between the inner and outer skins is stronger than we might tend to think. Still, on a steel string guitar that's going to have an end pin or end pin jack, I'd feel safer beefing it up with an additional end block. I would think another 3/8" of birch ply would do it, though. Even 1/4" of birch ply added to what you've already got would make it stronger, I'd bet, than a typical butt of non-laminated sides and a solid wood block. I certainly wouldn't go thicker than 1/2" birch ply. I might go 1/2" thick or a little more if you want to use a solid block rather than birch ply.

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Todd Rose
Ithaca, NY

https://www.dreamingrosesecobnb.com/todds-art-music

https://www.facebook.com/ToddRoseGuitars/

Or use spruce rather than hog. I guess that 1/2 to 3/4 of a regular width will suffice.

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Build log

Brad,

That is a very interesting process to say the least!

Just a couple of quick questions on your materials:

What are the dimensions of your Nomex and where did you purchase it? I have nomex for a double top I'm planning from LMI, however, the cells you use appear to be wider than mine.

Also, do you plan to drop side braces from your ribs due to the laminated process. Would the nomex provide enough of a "rip stop" for any potential cracks?

Again, very interesting design and process!

Ray

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Guitar Building = Continuous Improvement Process

For the sides I used 1/4" thick "Flexible Cell" Nomex. This allows the Nomex to flex easily in one direction. I purchased the materials from ACP Composites.

http://www.acp-composites.com/honeycomb.pdf

As for potential cracks, I believe the Nomex would provide "rip stop" but have not conclusive way of proving this.

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Brad
Avon, OH

Excellent info and tutorial Brad. I suspected that this was how C. Fox did his Ergo when he showed it to us in class. He used
a solid kerf though as it appeared to me. His only complaint was that the dbl sides and top, and eliminating much of the
bracing, didn't really make a big weight difference on the guitar. IMHO, it was one of the lightest, finest sounding, easiest
playing instruments I've ever handled. It almost seemed as though it was anticipating what I was about to play and pulled me
in that direction. I thought it felt lighter myself but that was probably because I was already floating from holding and
playing an Ergo. But then, what do I know? I've only been playing since I was 12 and there are many far better players here than me.

Thanks again Brad for all the info and instructions this is cool!

Couple of questions I'd like to add if you see this Brad is, did you find that the outter laminate was thick enough when scraping the
sides to level them after the boat was assembled? Or was the side assembly fairly level already due to the nature of the Nomex?

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Bill Hodge


One does not simply, own enough guitars!

Bill...glad to see you enjoyed the info. To this point I have put together 2 double side sets and from a construction stand point I have found that the sides once assembled are very flat and hold their size well. I basically bend the sides, laminated the outer side to the inner side assembly (inner side, nomex, and linings) and when dry I joint the two haves with the neck and tail blocks. The final rim set is very rigid and almost perfectly level. I would like to note that I built and use a special side bender that uses very little water in the bending process which helps minimize side distortion as a result of bending. (I posted something a while ago about the bender...it is in the archives)

Here is Imbuia outer set with a Anigre inner side.


Here is a picture of the amount of distortion against a scrapper straight edge after the laminating process (measured .002-.003 with a feeler gauge)


I am still working on finishing the first guitar so I can't comment on the sound but have been pleased with the results so far.

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Brad
Avon, OH

Double tops, double backs and double sides.....I don't get it personally. I've played guitars with one or
two or even all three implemented in their construction and am yet to hear evidence of a tonal benefit of
any of them.

With the top contributing a major portion of the tone and dynamic properties that a guitar will have and
the back and sides making their own contribution that can't be dismissed or disputed to the color and
harmonic properties of a guitar, I've noticed a few things.

With double topped guitars with two different species of wood being laminated together to form the top,
the guitars exhibit the tonal characteristics of neither of the woods clearly so much of what the player is
looking for by selecting a particular species is gone or minimized.

The same has been true of the double sided and double backed guitars that I've played. The properties
that make particular woods so desirable to many players are lost or mixed into what is a mix of tonal
properties.

I'm yet to play a single double constructed guitar that has any better tone, volume, dynamic range or
response than any that I've played with single layer top, back and sides. Maybe I'm missing something,
but I'm listening closely.

Maybe it's just because I'm an old school guy, but when I hear something that offers tonal benefits and
improvements over old proven methods that can't be denied, I'm all ears. I just haven't heard it yet on any
these fronts.

Regards,
Kevin Gallagher/Omega Guitars

Thanks Brad, I'll have to try it sometime.

Kevin, I'm no expert for sure but the aesthetics of them are very pleasing. For that matter so are the aesthetics of
a well built "old school guitar". I think the beauty of the sound and feel of Charles Fox's guitar was that it was
built by a 40+ year veteran luthier and up till that point, I'd never handled such a beauty Part the touch of a master's
hand and part my being enamored with such a fine piece of art. I guess I felt like a big kid with it.

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Bill Hodge


One does not simply, own enough guitars!

Kevin, I think the advantage to double top guitars is that they are able to be louder due their lightness. The timbre (voice) can be pleasant or not depending on the listener. A lot of players and listeners complain that they don't care for the sound of some of the loud, light construction guitars. Personally I believe it can be seductive when playing one, ignoring the pleasant quality of the sound in favor of bringing out a particular passage for clarity.

A lot of it is hype also, "double top is twice as good", sort of in the Spinal Tap style.

I am kind of partial to the jangly sound of a well made solid wood steel string or a nice twangy, throaty Torres style, classical. However, I like playing in an ensemble with a loud instrument that can cut through the mix and still sound like full guitar.

Some double sides are stiff enough to not contribute much to the sound no matter what they are made from. Same with double backs, but not always. I made a double back (and top) guitar that has a resonating back. The sides are pretty stiff and the sound is real loud. It is a steel string guitar and does not have a particularly pleasant voice, but is great in it's own right due to its clarity and volume. The so called "australian" or Smallman type classicals have totally non working back and sides which allow all of the string energy to allow the top to vibrate.

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Ken