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  #31  
Old 11-18-2018, 06:06 AM
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After the rosette glue dried overnight its time to sand the top to thickness on the wide belt sander:










We sand thickness the top to a predetermined stiffness by measuring how much the top bends under a standard weight. This tool is called a deflection jig:
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  #32  
Old 11-19-2018, 06:58 AM
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After the top has been sanded to my predetermined deflection measurement the next step is the graduate the soundboard with a hand plane.









After the top has been graduated its time to brace the top.












As the top braces are drying the sides are laminated:






























































Then a beautiful helping hand magically appears to hand me clamps as I clamp the outer caul to the side mold:










And so it rests for 24 hours as the glue cures and permanently bonds the double sides together:
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  #33  
Old 11-20-2018, 07:28 AM
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After 24 hours the sides are removed from the laminating form:










Each side is individually placed inside the body mold and the ends are marked to the appropriate overall length:





















... and then trimmed on the table saw:











Finally the excess glue is removed from the interior of the sides by sanding with a random orbital sander:
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  #34  
Old 11-20-2018, 03:13 PM
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So much fun to watch. Such good pics I feel like Iím there.

Flax is working. Happy Thanksgiving all!
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  #35  
Old 11-21-2018, 06:39 AM
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Quote:
Originally Posted by cigarfan View Post
So much fun to watch. Such good pics I feel like Iím there.

Flax is working. Happy Thanksgiving all!
Thanks for watching and following along Dennis. Happy Thanksgiving to you and your family as well. Glad the flax is kicking in too




After the inner sides are sanded then its time to attach the end block and neck block:



















































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  #36  
Old 11-21-2018, 06:44 AM
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Even your blocks are pretty!
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  #37  
Old 11-21-2018, 07:22 AM
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Even your blocks are pretty!
Thx but hey, a guy's gotta keep with the stripe-y theme, right?
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  #38  
Old 11-23-2018, 05:45 AM
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Whilst the blocks dry we inlay carbon fiber bars into the peghead to neck transition.












Bookmatch the peghead overlay:









Clamp:









Glued:










Then scrape the excess glue off:
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  #39  
Old 11-23-2018, 02:09 PM
Knives&Guitars Knives&Guitars is offline
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Loves watching every aspect of your build! Beautiful.
Curiosity questions:
*I assume the carbon fiber bar is to give added strength between the neck and headstock? Do you find any Sonic advantages as well?
**What does Laminated sides to for Sound quality? or is it strictly a Stability additive?
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  #40  
Old 11-24-2018, 08:01 AM
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Quote:
Originally Posted by Knives&Guitars View Post
Loves watching every aspect of your build! Beautiful.
Curiosity questions:
*I assume the carbon fiber bar is to give added strength between the neck and headstock? Do you find any Sonic advantages as well?
**What does Laminated sides to for Sound quality? or is it strictly a Stability additive?
Good morning K&G. Glad you are enjoying following along on our clients build. You pose some valid questions which are not easily answered in a short reply so grab a cup of coffee as I endeavor to answer your questions. Many of our modifications have been the result of seeing real world accidents happen to guitars and then engineering added elements or methods to prevent future structural failures. Since I am a mechanical engineer by trade its hard to turn that off when I approach building musical instruments.

The area of the neck, just under the nut, is often the thinnest and weakest area of the entire neck and one of the most common areas of the neck to fracture during shipping "whiplash" or from falling off a stand at home or on stage. It bears mentioning that since this is a weak area already this is just one of the reasons why I prefer to put the truss rod adjustment access at the sound hole. If the truss rod adjustment is at the nut even more material has to be removed for adjustment access, from an already inherently weak area, so it stands to question why add to this existing weakness?

Some builders use a laminated neck to address the problem of nut area weakness when using an upper truss rod access adjustment port. Its my personal preference to continue to use one piece necks, as long as 12/4 wood is still available to support our builds.

We inlay two short carbon fiber bars, from the peg head and into the upper portion of the neck shaft. This greatly enhances the torsional and longitudinal stiffness of that upper area of the neck shaft. In our testing we have never seen a peg head fracture due to whiplash or falling off a stand. We used to inlay two CF bars the entire length of the neck but this yielded too much longitudinal stiffness that it was almost impossible to make accurate relief adjustments with the truss rod. Another factor to consider is that full length CF rods add to the overall sustain of the instrument, which may or may not be desirable? I've not noticed any sonic impact when using the shorter CF bars so we will continue to use them as OEM specs.

First off, laminated sides are not my invention but one that I picked up from Ervin though there may have been someone preceding him to use them? I'll summarize and paraphrase Ervin's analogy before I get into my own. He says, in simplest terms, that a guitar shares a lot of similarities with the construction of a drum. A drum has a thin top, a thin bottom and a VERY stiff rim. The drum's rim is its structural element which supports the top and bottom. Drum rims are laminated for strength and are considered a structural component of the drum and not a sonic element.

My analogy builds on Ervin's but these are my words and not his. True lamination's, as in plywood, alternate grain direction in 90* increments with every successive layer of wood in order to build its strength in "plys". The more "plys" generally equates to more strength. 1/4" plywood is stiffer than 1/2" plywood and so on. Lower cost guitars often use laminated "plywood" sides, for strength, with little concern for tone. Tap a piece of plywood, any plywood and let me know how it sounds. I have and it's about as sonicly exciting as tapping on damp, limp cardboard.

Our "Double Sides" are not true plywood because we use two layers of wood and both layers of wood have the grain running in the same direction and not alternated in 90* layers. Our inner layer typically has the grain orientation either slighted skewed off parallel or skewed by using a slightly rift sawn cut of wood, each depending on the grain orientation of the outer layer of wood. This lamination method provides tremendous stiffness but since the grain of both lamination's are running in much the same direction it doesn't seem to impede or damp the tone. We can tap our sides and they sound sonicly similar to single sides so there is no negative effect in terms of the sound and vibrations that the sides may or may not contribute to the overall sound of the instrument.

If you look inside the sound hole of a guitar and you see cross grain strips of wood, tape or fabric glued to the sides its a good indication that the sides are a solid single layer. If you don't see these strips then its highly probable that the sides are laminated in some fashion.

I have seen single sides crack because "stuff" happens in the real world. Guitars get dropped, bumped on the corner of a coffee table, kids play with them and incidents just magically happen by unknown gremlins in the night. The cross grain strips, that are glued to the inner "solid" sides, are there to hopefully keep a gremlin induced crack from propagating past them and with the goal to keep the crack localized between the two cross grain strips. I've also seen cracks travel past these strips so its certainly not a fool proof design because "stuff" magically happens.

We have a demo set of double sides that we show to people touring our shop. We have beaten these sides against the corner of our workbench to the point that the bench corner is no longer sharp but rounded over significantly from so many beatings. However, the sides are still in tact with not so much as a slight dent on the exterior of them. Glue gets forced through the two thin lamination's during our clamping process and as the adhesive permeates both side layers of wood, this seems to bond the inner and outer sides, along with the adhesive, into a single structural element.

We were building a guitar, for one of Carrie Underwood's band musicians, who was to leave soon for a tour in Europe. I had the guitar body assembled and clamped into a vise and it was slipping while I was working on it. My hands were a mess so I asked my helper to tighten the vise, you know (righty-tighty). Well ... you probably have an idea where this is going ... she accidentally loosened the vise handle (lefty-Lucy) and the body fell to the concrete floor landing on its side after bouncing a few times. She was in tears and just walked away. L_o_n_g story short, the double sides survived the fall but one face of the guitar was not so lucky, which required replacing the top. This was a major setback for us and our client since we couldn't get his guitar delivered in time for the EU tour. It all worked out in the long run and he named this guitar after his daughter who was just born in the interim so we gratuitously inlayed his daughters name into his guitars fret board as a token of his understanding of our mishap.

Great sounding guitars have been built with single ply sides and also plywood variants so there are lots of ways one can approaching building instruments. This doesn't mean our guitars are better than everyone else but rather its just one of the methodologies that we have chosen to build by.
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  #41  
Old 11-24-2018, 09:38 AM
Knives&Guitars Knives&Guitars is offline
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WOW!
I am most grateful for this very thorough & thoughtful reply.
While I am not a builder of guitars myself, I am a bit of a scientist( a mad scientist) and really enjoy learning all the aspects of the acoustic guitar building and how each step could effect tone & or durability.
Not only was your answer complete and very clear in ever aspect of my questions, but you were also so wise as to reveal that there is no definitive. Open mindedness always leads to better discoveries.
Look forward to see this build completed! May it turn out even better than expected.
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  #42  
Old 11-24-2018, 09:56 AM
Knives&Guitars Knives&Guitars is offline
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After your great reply, I can not help but ask one more.
From other experiments I have done, I am under the assumption that the peghead overlays do make some tonal influence. I noticed that you are using Braz for headstock overlay instead of using cocobolo to match the back and sides.
Are you doing this for tonal influence? Or is it strictly a cosmetic addition.
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  #43  
Old 11-24-2018, 11:15 AM
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Great thread and pics!
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  #44  
Old 11-24-2018, 06:05 PM
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Beautiful work there, Tim! Enjoyed the photos.

Ken
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  #45  
Old 11-24-2018, 06:09 PM
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Quote:
Originally Posted by Knives&Guitars View Post
After your great reply, I can not help but ask one more.
From other experiments I have done, I am under the assumption that the peghead overlays do make some tonal influence. I noticed that you are using Braz for headstock overlay instead of using cocobolo to match the back and sides.
Are you doing this for tonal influence? Or is it strictly a cosmetic addition.
I will be shocked if this is the case. I can not believe a headstock veneer will affect tone at all.
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