Official Luthiers Forum!

[QUOTE=peterm] BTW, does anyone have the tutorial on building a two-top guitar with Nomex? I saw an article on the Guitar Maker magazine (if I'm not wrong) and it showed the process.
I would like to see that or any other info on using nomex...

Thanks[/QUOTE]

Take a look at
   http://dunwellguitar.com/DoubleTop/DoubleTop.htm
That shows a run down on how I'm doing it. I have changed a bit some of the steps but it will give you the general idea of the process. Chat with me offline if you want more detail.

Alan Dunwell

Cool there Alan.

I also like the powered dish sander you got there.

Thanks for sharing.

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Thanks peterm, just curious, good luck with it and I look forward to the results.

Mike
White Oak, Texas

[QUOTE=Rod True] Cool there Alan.

I also like the powered dish sander you got there.

Thanks for sharing.[/QUOTE]

De nada Rod. I've got other jigs and doodads (sorry to get technical on you there) that I keep meaning to put up there but time is the enemy. RSN (Real Soon Now) Also check out
http://coloradoluthiers.org/
and the Tips and Tricks for some more stuff from others in our Colorado Luthiers group.

Alan D.
dunwell38988.6266319444

I've seen a photo (and I REALLY wish I could remember where!) of a true double-top guitar. The luthier prepared one top, containing the soundhole, and put another, partial, top over its lower bout, which held the bridge (IIRC). The two tops were separated, but the caption gave no information about how it was braced . It supposedly has a very good sound. This instrument dates from well before anyone thought of using an industrial product like Nomex in a guitar, so I'm assuming it's all wood. When I first heard about new double top guitars a few years ago, I thought people were doing something like this earlier luthier did.

Is anyone else familiar with that guitar?

Peter, here's a picture of the way I do my double tops. I wont go into the whole tutorial as I pretty much do it exactly like Alan. Nice photo tutorial Alan. I use slightly less honeycomb than Alan, some people use more like Alan and some use less than I use.
I do however use some heat to help with the curing and bonding of the Nomex to the spruce skins. Not that I've had any problems not using heat, I have it available and it helps with the filleting of the epoxy to the core, so I use it.
My skins are approximatley .03 thick with the core being about .06.
The double tops I've made seem to be very stable.

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Jim Watts
http://jameswattsguitars.com

Jim, thanks for your input! It looks great. I am leaning towards the honeycomb style in wood using only 2 skins...

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Peter M.
Cornerstone Guitars
http://www.cornerstoneukes.com

Carlton,
I think the design you're talking about is from either Lloyd Loar (post-Gibson) or maybe from Macaferri.

Troy

Jim, very slick design. What you are doing follows with the idea that most of the tone is a result of the lower bouts. Good thinking. I see you are keeping the slip between the bridge plate and the tail block. Is this for anything other than strength issues? The studies in classicals at least seem to indicate that it isn't necessary for the strength of the top and there isn't any more bow-up or curvature to the top over time without it. And on my double-backs I'm doing them full Nomex. Do you have any Chladni modes for this top design? I'd love to see them.

Laters,
Alan D.

Carlton, I don't know about the design you mention but I know that it the past there were guitars that had an additional "top" contained within the body. IIRR this was a sort partial of floating plate just below the regular top blocking the soundhole area and had cut-away parts out near the ribs to allow air flow. I have never seen/heard one in person so I can't comment further on them. It does sound kind of "Virzi" like though so maybe Mr. Loar had something to do with them.

Alan D.

Nope, not Loar or Macaferri. And it was very different from a Virzi system. Loar, I think, tried a double side design, and he, or someone else (can't remember) did a double back. Ramirez has a patent on an interior soundboard design. Lots of interesting experiments have been done with the guitar, and I bet some of them might have been beneficial with a bit more work, but they didn't sell, so they weren't developed further. The quest continues!

I'm thinking Lance might be willing to sell you one of his LS redwood tops for such an experiment. Lance?



Yeah, I know...not a chance!

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"I want to know what kind of pickups Vince Gill uses in his Tele, because if I had those, as good of a player as I am, I'm sure I could make it sound like that.
Only badly."

LAnce, thats very kind of you!

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Peter M.
Cornerstone Guitars
http://www.cornerstoneukes.com