Cuban Mahogany and Lutz Spruce 00

[Darryl Young]

Took measurements on my Lutz soundboard material last night. Used a free tone generator program on my PC to produce Chladni patterns on the soundboard. Used the frequency certain modes formed to calculate the Young's modulus for stiffness along the grain, cross grain stiffness, and the Shear Modulus. I programmed this into a spreadsheet. Using info from the new Trevor/Gore manual, I added code to calculate the thickness of the soundboard. It calculated my top should be 0.095" thick for the 00 body I'll be using. This would likely be perfect for Gore's fingerpicking guitars. I may want to go a bit thicker for a strumming guitar for my daughter, not sure. Here is a screen shot of the Excel spreadsheet I created if it interests you. You can see the modulus of elasticity (Young's modulus) values it calculates for long grain (El), cross grain (Ec), and Shear Modulus (Glc which is like twisting stiffness). The final calculation for top thickness has a pointer to it in red. BTW, I can use the same calculations to determine my back thickness (but only have data in this spreadsheet for the top).

00PlateProperties.jpg

[Darryl Young]

Joined my Lutz top a couple nights ago. On one side I pulled up a few spruce splinters while removing the tape so I had to be careful which direction I pulled. The other side was much better so maybe I didn't get the fish glue completely wiped off before I applied the tape, not sure.

Here is a pic of the joined top. It's very silky!!!......which I love! Ordered a rosette from Martin today. They've been closed since Thanksgiving so today was the first day I could order. Unfortunately, they are backed up and shipping is backed up.......so while they said they would get it packaged today, they also said it could be a couple more days before it gets shipped. Bummer!.......the next thing I need to do is install the rosette.

JoiningTop.JPG

[Darryl Young]

Cocobolo headplates and binding came in today along with the African Blackwood fretboard. This was from Hibdon Hardwood and I think he sent some nice looking Cocobolo. I ordered 3 headplates and he sent me 5 headplates that were consecutive cuts from the same board. The inside and outside plates from the board were seconds (one a bit thin on one end and the other had a rounded edge on the side) but I thought it was very nice of him as they will be great for endgrafts, heel block, etc.

The African Blackwood is amazing (a true rosewood)! I sanded it flat on both sides this evening and it has an awesome sweet smell similar to Brazilian Rosewood. I left it about 0.300" thick and it still rings loud and clear when you tap it and the sustain is unbelievable. Compare this to typical ebony with high dampening. Not sure the fretboard adds much to sound......but if it does, this is as good as it gets I'm guessing. I would love to build a dread out of this.......but it would be about as cheap to build from BRW ($700+ for a set).

Here is a cell phone picture of the headplates I picked out to use on front and back of the headstock. They are laying on the ABW fretboard but you can't see too much of the fretboard in the picture.

Headplates&Fretboard.JPG

[David L]

Darryl, I just love African Blackwood, I have a rosette blank that I got from the Zootman that will be used with the Blackwood B&S guitar when I get to that one. Another thing that I like about Blackwood over Ebony is that sometimes Ebony doesn't look like wood if it is the highly desireable pure black with no streaks, this is especially true if it's under finish. Blackwood has some color/grain variations that are nice looking plus it has an inner chatoyance that Ebony doesn't. Don't get me wrong, I am also a big fan of Ebony too. I would really like to see a better picture of that FB. The Coco headplates look sharp also.

David L

[Darryl Young]

I'm with you on the Blackwood David. The more I handle this board the more I would love to use it for a back and side set. The ring duration is surprising.

[Darryl Young]

David, this is the best I could do with my cell phone (this pic set on high resolution).

BlackwoodFBCocoFP2.JPG

[David L]

Yes, yes, that's what I'm talking about, even with a cell phone camera you can see some variant grain lines. To me this is desireable and I haven't even touched on the tone qualities as you have, mostly because I don't what I'm talking about in that area.

David L

[Kevin Sjostrand]

That is some pretty Rosewood too Darryl. I for one am a fan of wide, colorful grain in rosewood, not the drab, straight, tight grain, nearly mono-color wood that is suppose to be "premium" EIR.
Yes, imagine how good a whole guitar would sound using that Blackwood....I have read (but never heard one) that it makes an amazing guitar.
David, do you have a set of Blackwood waiting in the wings?

Kevin

[Darryl Young]

If he does......I'm very jealous!!! <smile>

[Darryl Young]

Had Andy Birko (from the OLF) CNC my fretboard. He cut the fret slots so they don't go all the way through the edge of the fretboard (faux binding). I had him use 0.025" nut compensation and it has a compund radius. I used a 14" radius at the nut end of the fretboard. He cut the fretboard today and e-mailed me a pic. So here is what the African Blackwood looks like after milling (more choclate colored):

FretboardAfterFretSlotsCut.jpg