Hatcher High Figure Koa Penelope Sisters - Steel String and a Nylon Crossover
 

In February 2011, my wife and I took a couple weeks in Hawaii. It was very inspirational to see where the woods I have the privilege to work with come from.

http://farm8.staticflickr.com/7014/6...29d801e8_z.jpg

Here is a picture of a beautiful old Koa tree we discovered during our adventures.

http://farm8.staticflickr.com/7162/6...939ff3a1_z.jpg

Since that wonderful vacation I came across this gorgeous Koa board.

http://farm8.staticflickr.com/7156/6...65d4bebf_z.jpg

Here is a closer view.

http://farm8.staticflickr.com/7148/6...9de1db52_z.jpg

Even really close, it is hard to believe that this is a flat surface!

http://farm7.staticflickr.com/6096/6...6f34426d_z.jpg

This board is 42" long, 5"-10" wide, and 2" thick. The first order of business was to get it resawed to see what it would yield.

http://farm8.staticflickr.com/7154/6...c9e96ce6_z.jpg

I won't pretend that I resawed it myself. I have a decent 14" bandsaw but with all that figure and 10" width, I didn't want to risk it, so I sent it out to Dave at Borson Precision Resaw. I got back 12 great boards and 1 extra for faceplates etc! From each board I can get two back halves or two side halves. That's enough for six guitars!
The board still needed some drying when I got it. The pictures above do not have Naptha or anything on them though. Cut down thin they will dry much faster. The process for drying these is called "stickering" because you use "sticks" to open up the cuts so you get even airflow and control warping and cracking. By spacing the sticks both above and below the boards they can dry evenly and with pressure you can prevent warps and cracks. I covered it with plastic to start out. This slows the initial drying some and helps slow the shrinkage. This also reduces cracks.

http://farm8.staticflickr.com/7019/6...d695bb47_z.jpg

This set of wood gives me the rare opportunity to build book matched guitars. I am going to build two of my Penelope models, but with a twist,
one of them will be a nylon crossover. I will build them side by side on this thread so we can compare and contrast the processes and result.
While the Koa dries I'll get everything together for this project.

Thanks. I hope you enjoy the ride!

Oh boy! Thanks for sharing Mark; I cannot wait to follow this thread.

Happy New Year everyone.

Those are great pics -- and that Koa is stunning, to say the least!

Thanks for your comments.

Here is a link to my Penelope page on my website: http://www.hatcherguitars.com/models/penelope/

The Penelope on this link has a Western Red Cedar top and a cutaway. I am going to use Swiss Spruce and no cutaway on the guitars I'm building on this thread.
I am also changing up the trim and will have my sculpted headstock on the steel string. The crossover will have a whole new head design that I'm testing out now.

Right on Dude.

Thanks for sharing the photos.

Solo

Hey Mark - Still intend to make it down to your shop since I'm just up Rt 9 from you. What was the outcome with the beautiful cocobolo you had up a couple months ago....?

Regards,
Robert

Happy New Year!
 

Hello Solo and Robert

The Cocobolo guitar is still coming along. I'm French Polishing the neck and am waiting to get the body back with the back and sides finished with polyester. That should be soon and I'll be posting the finishing steps and set up. Then it will be going on a road trip. I still can take names for anyone interested. http://www.acousticguitarforum.com/f...d.php?t=227187
I moved and am now up the road from you in Milltown. I welcome you to come up and see the shop etc. I'd suggest you come up in 3-4 weeks as I will probably have that Cocobolo guitar back then, the shop will be more set up, and I'll be further along with these Koa sisters

Drying the Koa
 

After a week the plastic comes off and I can start to circulate the air a bit.

http://farm8.staticflickr.com/7031/6...bbf06b6b_z.jpg

From there it's just a matter of waiting until it reaches my target moisture level.

http://farm8.staticflickr.com/7152/6...2ca2983a_z.jpg

Hi Mark,

your Koa is wonderful!
Is 7% moisture your target for this wood?
and, btw, happy new year ;)

Q.

Hello Q

Yes. 7% is fine. It will be stable from here, so I can now start to cut the slices down to the back and side blanks. To get the backs and sides for this project I'm cutting four of these:

http://farm8.staticflickr.com/7164/6...c61e6933_z.jpg

And four of these for the sides:

http://farm8.staticflickr.com/7035/6...ba8a29a4_z.jpg

I can use the end cut for headstock laminates etc.
So from this I'll get enough for four guitars or two pair of book matched sisters. I'm picking the best pair for the Penelope sisters:

http://farm8.staticflickr.com/7015/6...385f5fcd_z.jpg

Time to select the woods. The figure in the Koa really varies from light to dark. I think having the Ebony black fretboard will help set that off especially contrasting against a very pale Swiss Spruce top. I'm using Cocobolo for the binding, tuner buttons, top crossgrain purfling, and bridge which I think will suggest the red in the Koa. Black and Maple purfling all around will help tie it all together. Here is a pic of the raw woods:

http://farm8.staticflickr.com/7157/6...7647869a_z.jpg

Thanks for viewing

Wow, gorgeous woods! I will look forward to watching this thread and seeing how these guitars develop.

Fliss

Hi Fliss,

Thanks for commenting. One of the best things about building guitars is that you get to work with such great materials!

Mark,

Fascinating... and beautiful! Thanks for sharing these pictures.

Top Wood Selection
 

I'm using Swiss Spruce for both guitars partly because I think the look is right but mostly because I think it's a wonderful pairing with Koa and this model guitar whether it is nylon or steel stringed. This wood is very light, stiff, and responsive to a light touch but certainly holds up very well to a little harder playing.
I went through all of my sets to find a closely matched pair. Both sets came in very light at about 5.7 grams per cubic inch. I also compared how stiff they were, both with and against the grain. Finally, I did the more subjective tap testing for tone and sustain.
The reason I'm going through all this trouble is to make as many things as close as I can on both guitars. There will be many more differences than nylon vs. steel strings when finished, but where I can, I'm going to start them off as close to the same as possible. In the end, I want to show what this guitar sounds like as a steel string and as a nylon crossover.

Here's a close up of the top wood, I'd tried to catch the silking in this photo even though this is dry and roughly sanded:

http://farm8.staticflickr.com/7151/6...6d760c94_z.jpg

Gluing up the first top:

http://farm8.staticflickr.com/7168/6...cdc556fb_z.jpg

Thanks for viewing!