Laminating sides, and a no water no heat bending method

[tippie53]

We both agree that in the end , it still becomes a guitar .
glad we can have a good discussion .

[Darryl Young]

Once a box is assembled, it seems the stiffness of the top/back/sides dwarfs any stiffness added by the lining no matter which style lining is used and no matter which axis is considered (due to the cube rule). So it seems it's primary function is to increase glue surface area (but as Ken mentions, the reverse lining stiffens the rim better prior to glueing the top/back in place). Afterwards, I'm guessing any difference is negligible. I'm amazed how strong the structure becomes after the top/back are glued in place. When I describe the gas mileage my car gets, I never consider if my 7 yr old daughter is in the car or not (yeah it makes a difference, but I doubt I could measure it). Same applies to the stiffness added by traditional or reverse kerf lining, the stiffness added by the lining pales compared to the stiffness added by the structure of the back/top/sides (assuming the glue joint doesn't fail).

As to laminated sides, it seems the player does get some tone/harmonics from the sides (subjective I realize). I doubt anyone other than the player would notice. I can definitely feel the vibration in the sides when my guitar is strummed. I would guess (here we go again <smile>) that the weight of the sides has as much impact on tone/sustain as the stiffness. Maybe laminated sides are heavier and contribute to sustain.

In lieu of laminated sides or extra thick sides, maybe solid linings are a good choice. It would add a bit of stiffness (how much impact could be achieved by not having kerfs?, not much likely) but you could increase the mass right at the boundary of the top (seems this is where it would have the most impact). If you wanted to add a little extra weight, you could use a hardwood. I'm guessing any differences are subtle.

[David L]

Again, probably out of my realm of intelligence, but if the mass is increased, wouldn't the weight be increased thereby decreasing the vibration capabilities. Again, if this statement is true we're probably talking about a difference that's negligible.

David L

[tippie53]

I Agree that is is slight . The laminated sides will take a hit better than solid so the cracking issue will be less

[Kevin Sjostrand]

[quote="Darryl Young"]Once a box is assembled, it seems the stiffness of the top/back/sides dwarfs any stiffness added by the lining no matter which style lining is used and no matter which axis is considered (due to the cube rule).

This is EXACTLY what I was thinking and was going to say yesterday, just couldn't get around to it.
Until the top and back are glued on, the lining variations may matter, but once it is all glued together, how much could it really matter?

Kevin

[Ken Hundley]

This is a tough one....I am not sure what to believe. If you treat the guitar similar to a drum (which I have...my impetus for moving the sound hole off of the soundboard, and why I like the idea of a cantelevered fingerboard), then is a stiffer rim a good thing? Not sure....migght depend on your intentions for the guitar, might depend quite a bit on what you WANT to hear in the guitar.

To me, a stiffer rim would reflect more energy....the energy coursing through this system we call a guitar would be less consumed by a stiffer rim (whether it be due to laminated sides or the possibility of more structural rigidity from reverse kerfing) than it would by more flexible sides. To me, this would mean that the guitar would exhibit more of the sound characteristics from the soundboard and back...forcing more of the sound out towards the audience, much like the thicker laminated rims in a drum.

If you built a rim that was more flexible, the guitar would be colored by, or take on more of the tonal characteristics of the woods the sides were made from. I can't consider this detracting from the top energy, though some could make that argument. It will certainly color the sound, in my opinion, and allow more of the characteristics of the back and side wood types to come through. Stricktly my opinion, no factual basis here, but just trying to think things through and voice what influences my building ideas.

[kencierp]

Again -- no one is denying that when the plates are attached the rim will become very strong no matter what kerfing -- the wrong assumption as I see it, is that the stiffer rim (the one with RR kerfing) somehow looses its original structural and perhaps acoustic characteristics/advantage and the playing field is leveled after assembly --- I believe that is flawed logic.

[deadedith]

We're covering a lot of ground here. To help me re-focus, here is an excerpt from Gore, talking about 'heavy' sides. It makes sense to me:
"This innovation is a major breakthrough in guitar design. I discovered the effect when I was testing guitars in their building mould, which adds considerable mass to the sides of the guitar. The frequency response of the guitar was different when it was in the mould to when it was out of it. The effect can best be described using a firearms analogy. When you fire a gun the bullet accelerates out of the barrel and the shooter experiences a recoil from the gun – the gun accelerating towards the shooter. If you immobilise the gun e.g. by holding, say, the butt of a rifle against a tree, or by making the gun heavier, the gun accelerates backwards less and the bullet accelerates forwards more. Same with a guitar; make the sides heavier and the body of the guitar accelerates less and the top accelerates more. The more the guitar top accelerates under the string’s oscillatory forces the more sound is produced. Having observed the phenomenon experimentally, I proceeded to model it mathematically to understand whether the effect was real or just some strange aberration. It’s real. The concept can be used to great effect in shaping the volume and tone of a guitar. How much mass to add, where to apply it and how to apply it are critical to the effect produced"

[Darryl Young]

Again -- no one is denying that when the plates are attached the rim will become very strong no matter what kerfing -- the wrong assumption as I see it, is that the stiffer rim (the one with RR kerfing) somehow looses its original structural and perhaps acoustic characteristics/advantage and the playing field is leveled after assembly --- I believe that is flawed logic.

Well, that isn't my argument. My agument is that after gluing the top/back the top and back become part of the unit as a whole and you can no longer consider the pieces individually (all pieces are contributing to stiffness). And in the assembled body, the large height of the sides (on one axis) and the large height of the top/back (on the other axis) contribute so much stiffness relative to the lining......that the type lining becomes negligible (or at least any difference between traditional vs reverse kerf lining is dwarfed to the point it has no practical/significant impact to the function of the guitar). So my point would be that reverse lining has a practical benefit during assembly (prior to gluing the top/back plates) but provides no significant structural benefits after assembly (though it may provide cosmetic benefits which is subjective).

[kencierp]

So does Bob Taylor and his engineers have it all wrong too?

http://www.rtaylorguitars.com/Woods-Details-01.aspx

All that extra work is for nothing since (if I am understanding the premise) all the structural advantages disappear after the top and back are glued on?