D15m has a plywood back???

[killdeer43]

Love the history, love the construction techniques/finer points, LOVE the guitars!!
I've always been fascinated by the basic concept of putting strings on a wooden box and making lovely (sometimes) music come out of that box. It's pretty amazing and heady stuff when you think about it!
All musical instruments have their own unique stories but it's always been the guitar for me. It's much more difficult, for instance, to take your Steinway on a camping trip! :shock:

Joe

 

[kostask]

Much as I'd love to think my '96 would have maple between the mahogany, Chazmo's explanation on Tim McKnights methods seems to indicate the middle layer(s) don't affect tone that much unless special materials/processes are used. I'd think it'd be a pointless use of the maple unless maybe for hardness? Or is maple actually more economical than the 'hog anyway so why not? (Ithought maple was more expensive?) Also see Hans' answer to West R Lee's question to him about how well he was doing when he thought it was all 'hog laminate, Hans said: "you're doing fine, West"... Would seem to imply it IS all mahogany... Is this another one of those questions whose answer will be revealed in Vol 2 of "the book"?
It just occurred to me this probably one of those tests with several correct answers! :lol:

Al,

I'm not sure you interpreted me correctly. I think most laminated guitars that you'll find out there (not Guilds!) get a bad rap because they're designed like solid flatbacks... the problem (I think) is that the laminated back and sides swallow up some of the sound. The Guild use of an arched back makes good use of the reflection of sound and not necessarily the resonance of the back. But, maybe Guild laminates are done with thinner slices; I don't know.

Tim's method is a pretty recent development in the guitar world, and indeed I think the intent there is to isolate the inside wood from the outside, which is almost the opposite of what you get with a normal laminate where everything is completely glued up together and stiff.

I'm just thinking out loud.

A lot of the bad reputation for laminated woods in guitars has to to with the late 1960s-today Oriental imports that used an inner layer of some soft material. This soft material ends up absorbing sound vs. resonating wth it, or reflecting it. There are fairly well regarded laminates around, most recently the red label Yamahas, and the Seagulls. In both of these cases, all of the laminations are made of a hard wood; I don't remember what the Yamahas used, but the Seagulls use outer layers of wild cherry, and and inner layer of poplar. It should also be remembered that the famous Selmer gypsy jazz guitars, as used by Django Reinhardt were also of laminated construction, and they sounded fine for their intended use.

I really doubt that Guild would have used sawdust in their laminates, as it would have beeen quite obvious sonically. The whitish wood could be maple (mostly because Guild used a lot of it on other guitars), or ash, alter, poplar, or even birch, all of which have been used as tonewoods at ome time or another.

Kostas

 

[GardMan]

I pulled the end pins on my G-37 and D-25... both appear to have solid sides. Also, both visible plies on the backs of both guitars appear to run ~the same direction... with the grain lengthwise along the body (on the D-25, the ply on the inside of the body is turned just bit, but certainly not crosswise).

Chazmo, I'd almost bet that the middle ply on the sides of Cap was a hardwood, and that your just seeing the end of the grain where it has been chewed up a bit by drilling the hole for the end pin. I'd almost be willing to bet that it's maple...because they would have those pieces around from making the maple F-50s.
D

 

[hansmoust]

I believe it has a laminated mahogany back, not plywood. I think it's done in layers, like plywood, but in thin sheets of mahogany, unlike plywood...... in order to mold the arched back. I think all the arched back models were done the same way.

Hans....am I close here?

West

You're doing fine West!

Sincerely,

Hans Moust

Hello folks,

There seems to be some confusion regarding my 'you're doing fine West' remark, which was an encouragement to West and not a statement about the exclusive use of mahogany veneers in the laminated back of a D-15. Only the outside layers are mahogany. The inside layer(s) can be various materials but usually they were poplar or soft maple. If you take a look at the unbound back of a D-15 or D-16, you can actually see the different layers.

Sincerely,

Hans Moust
http://www.guitarsgalore.nl

 

[hansmoust]

Here's a detail shot of a D-16 back:

Sincerely,

Hans Moust
http://www.guitarsgalore.nl

 

[dreadnut]

OK Hans, how about the D-25? What are the inner layer(s), also Maple or?

 

[hansmoust]

OK Hans, how about the D-25? What are the inner layer(s), also Maple or?

Yup! Same thing; poplar or soft maple!

Sincerely,

Hans Moust
www.guitarsgalore.nl

 

[chazmo]

Thanks for clarifying, Hans!

Dave, cool that you verified your sides are solid, but ...

Hans' shot of the D-15 back sans binding is pretty much what my '67 F-50R's sides look like, eh guys? So, perhaps there wasn't any magic going on here and if you drill through the backs (or peel the bindings off) of your laminates I'll bet you'll find a non-tonewood in the middle of the sandwich. Not that I'm recommending anybody do that!!!!!

I'm making a guess here, but we can probably cite two strong reasons for Guild's laminates performing so effectively compared to many of the laminate duds that gave laminations a bad name in the past...

1. The arched shape and commensurate lack of back bracing makes for a good reflective surface for the sound.
2. The use of tonewood on the inner surface of the laminate also helps reflectivity (rather than absorbing the sound).

Arching the back notwithstanding, keep in mind that a multi-ply laminate of the same tonewood like you guys were suggesting earlier would ultimately be wasteful as you'd actually use more of the wood than if you'd just gone solid. Of course, you could possibly allow for a middle layer of cheaper sections of the wood (and possibly multiple pieces), but it's still more of the wood. In fact, after talking with Tim McKnight about this, his double backs (Nomex sandwich) use more of the tonewood in question than solid backs. This is probably because he doesn't have equipment to cut thin slices of a log.

Anyway, again, just thinking out loud. Best wishes, and *PLEASE* don't start slicing open your guitars.

 

[killdeer43]

*PLEASE* don't start slicing open your guitars.

I'll try to resist. :wink:
Interesting thread, to say the least.

Joe

 

[dreadnut]

Well I certainly learned something about my old Guild today!

 

[plaidseason]

I'd argue that laminated flat backs (as found in so many, often cheaper, instruments) aren't even in the same universe as the Guild arched back design which was basically Guild's way of applying jazz/archtop guitar principals to flatback acoustic guitars.

The thing I've noticed with various arched back Guilds is that the sound projection is/was exceptional. I'm not sure they're always super nuanced, but a lot of times that's a good thing. Sometimes I think I'm looking for lots of subtle overtones, but in truth, I'm a sucker for volume and real projection.

My opinion is that the arched back design accomplishes the same goal as the Ovation round back, but with way more character and depth . . . whatever that means.

-Chris

 

[adorshki]

Thank you everybody ESPECIALLY Hans, Kostas and Chazmo for insights and factual backgrounds. I had no prejudice about quality laminates but I was still curious about the actual construction of our instruments, cause I just like to know that stuff. I did check my D25 again and the grain inside the guitar IS reversed from the grain outside on the back. Still parallel relatively speaking but definitely reversed.
Now for the next question: I seem to remember hearing somewhere there was a higher silver content in the Guild frets which made for better tone but slightly less durabilty........? DON"T EVERYBODY PILE ON AT ONCE! :lol: :lol: :lol:
(true story thouogh, now that I think about it I think it was the guy who did my first re-fret.)

 

[killdeer43]

I just have to throw my D15 onto the pile.
As with the pic from Hans, you can clearly see the three layers of the back, as well as the solid top....and the neck, etc.

We do have fun here, don't we? :wink:

Joe

 

[kostask]

....
So, perhaps there wasn't any magic going on here and if you drill through the backs (or peel the bindings off) of your laminates I'll bet you'll find a non-tonewood in the middle of the sandwich. Not that I'm recommending anybody do that!!!!!
.....

Chazmo:

Poplar is just as valid tonewood at alter, ash, pearwood, lacewood, cherry, and a variety of other lesser used hardwoods. While it isn't commonly used in acoustic guitars, poplar is used in electrics, and there is nothing that makes it a "non-tonewood". A lot of people look down their noses at birdh, but a fairly high percentage of the early, Gibson Lloyd Loar L5s have birch back and sides, not maple as is typically assumed. They sound fine and are just as durable as the maple L5s from the same era. Ken Parker, of Parker Fly fame, specificially chose to use poplar bodies due to poplar's resonance characteristics.

High quality laminates, as used by Guild in their arched back guitars, are differentiated from low quality laminates (as in the notoriously bad sounding 1960s-now Oriental import guitars) by the use of a hardwood center layer, vs. the soft, non-hardwood center layer of the low quality laminates. In many cases, there is a process of determining the "best" inner layer lamination to use, and isn't a choice taken lightly.


Kostas

 

[chazmo]

Hi, Kostas.

What I actually meant to say was simply that the center layer wasn't the same wood as the tonewood that's used on the outer and inner layers, which we've pretty much established. However, I'm not entirely convinced that the composition of the center layer is the differentiator that you suggest it is. My only evidence to support my doubt is that I don't feel much resonance on the outside of the back when I play. Nothing like what I feel with a solid back. I don't really know if that's relevant or not so I won't push it. All I know is that Guild done it right!

Best wishes.

 

[killdeer43]

This thread's interest quotient remains high, so check out this shot.

Intriguing, no?
Joe

 

[chazmo]

Joe, guys, I thought Hans' original D-15 picture was with binding removed, but do I take it correctly that these guitars' backs are not bound? In other words, in these pictures, are we looking right at the cut side of the laminate back?? I find that surprising, actually. What are we looking at??

There's all kinds of white plastic binding on my arched Hoboken F-50R so the construction of the back was not at all obvious until I pulled the endpin, and that only told me something about the sides of the guitar until Hans confirmed that this was also the way the back was done...

 

[killdeer43]

Joe, guys, I thought Hans' original D-15 picture was with binding removed, but do I take it correctly that these guitars are not bound? There's all kinds of white plastic binding on my arched Hoboken F-50R...

Chaz,

You are correct....no binding at all. I have to say that the transitions between top/bottom and sides are really well done. To the touch, it's seamless and you can see how it looks.

Joe

 

[chazmo]

That is fascinating. I guess with no back bracing to worry about, there's no aesthetic need for binding (to cover that up); just cut the back smooth, kerf it on the interior and glue up the box!

 

[killdeer43]

Seems to work just fine; although, you might think they would have at least put a bit of stain on the odd wood in the sandwich to make it blend better. :wink:

Joe