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Jason Wolverton
01-30-2017, 07:17 PM
It's been a little while, but I'm finally building another uke.
This one has a cedar soundboard and Brazilian back and sides. The back is arched/braceless with a carbon fiber core (borrowed from my classical guitar construction technique). The head features a recessed panel which is another thing I've been doing on my guitars.

Should be done soon!

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Jason Wolverton
01-30-2017, 07:19 PM
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Jason Wolverton
01-30-2017, 07:22 PM
Reverse fan bracing. European spruce.
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sequoia
01-30-2017, 07:29 PM
Very nice work. Love the rosette.... Not familiar with reverse fan bracing. No bridge patch?

Jason Wolverton
01-31-2017, 09:27 AM
I used a bridge patch for several years on my guitars, because that's what my teacher did. Now I've come to the conclusion that they aren't helpful.... at least in classical guitars. Used on a uke, where there's even less soundboard area and stored energy in a string, I can't see how a bridge patch could do anything but add weight; thereby decreasing responsiveness. We want to get that soundboard moving!

sequoia
01-31-2017, 07:09 PM
I can't see how a bridge patch could do anything but add weight; thereby decreasing responsiveness. We want to get that soundboard moving!

I think about this question a lot and I follow your thinking about getting that soundboard moving, but what about bridge rotation over time? Without a foundation like a bridge patch that bridge is going to rotate on your soundboard due to the pressure of the strings. Thus your calculated scale length and added compensation is going to change over the years and eventually the uke is going to change and the scale length is going to shorten. Unless! You reinforce that area underneath with braces... I still have not figured this part out. Until such time as I do, I will continue to use bridge patches.

Jason Wolverton
02-01-2017, 08:03 PM
My belief is that a bar under the bridge will do a lot more to halt soundboard deflection than a pad will. Anyhow, there's more than one way to skin a cat as they say... :)

Jason Wolverton
02-01-2017, 08:05 PM
A couple more photos of the progress.
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gabefranco
02-02-2017, 06:41 AM
Brazilian rosewood? I've never seen a piece with such contrast in the sap wood before. Looks like beautiful stuff.

Question on the braceless back; Is it a sandwich of wood/carbon fiber sheet/wood? How thick is the carbon fiber?

Also, your rosette is really stunning. What material is the field for the half dots made of? End grain black palm?

Jason Wolverton
02-02-2017, 07:34 PM
Yessir, the center is Black Palm. Thanks for your compliments.

Correct on the sandwich. I make the two outer skins about 1.2 mm. The carbon fiber cloth is pretty thin, and gets compressed a little when I put in in the vacuum. The final thickness is about 2.75 mm. I do this frequently on a larger bodied classical guitar design that I make. First time trying it out on a ukulele.... Just to amuse myself and see what happens.

pahu
02-04-2017, 07:04 AM
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Nice work. Are you using 'extra' bracing to compensate for lack of bridge patch?
Is your work-board radiused?

Jason Wolverton
02-08-2017, 10:26 AM
Hi Pahu,

I'm not convinced bridge pads do much to prevent caving. I think it's better to use a bar under the bridge if you're going thin with the soundboard, and use strong enough braces too.
This particular soundboard is thick enough and stiff enough not to warrant a bridge pad.
Yes, my work board (for this style of uke) has a radius in the lower bout. I starts from where the bridge is placed.

Another photo of the top...97693

sequoia
02-08-2017, 08:00 PM
Nice clean work. I love doing rosettes but have never done anything that involved. Lovely... I forget what size this ukulele is, but on my tenors I'm still going to put in a bridge patch. It just makes sense. If it is a soprano, then I could see leaving out the patch. Maybe.

Jason Wolverton
02-24-2017, 08:31 AM
A few more photos. French polishing...still tedious even on a uke. haha Love this flamed mahogany neck though.
Because cedar is soft and FP is delicate, I thought a pick guard would be good. I'm using figured walnut that matches the head panel, butt join, and armrest.
I like to use TruOil on pick guards and armrests because it's SO easy to touch up.
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sequoia
02-24-2017, 06:16 PM
Love this flamed mahogany neck though.


Yes, love the flamed mahogany neck. Quite lovely.

Jason Wolverton
03-01-2017, 08:38 PM
Glueing on the bridge. One of the last things to do.
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sequoia
03-02-2017, 07:12 PM
That is one nice looking uke... Interesting way of gluing down the bringe. You must have some sort of gantry thing? Mind showing pictures? I'm intrigued. More than one way to skin a cat or glue on a bridge if you know what I mean.

Jason Wolverton
03-02-2017, 08:36 PM
Sequoia,

It's just in a standard go-bar deck with one clamp in the middle. My go-bars are a little different is all...

Jason Wolverton
03-12-2017, 10:15 AM
The completed uke.
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Jason Wolverton
03-12-2017, 10:22 AM
A few more...
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Alytw
03-12-2017, 04:09 PM
Wow, that looks spectacular.

greenscoe
03-13-2017, 12:41 AM
Its a great looking uke. You have employed a few interesting and unusual building methods as well as the more visible decorative features.

In particular I'm wondering how the instrument sounds. I've built with cedar but with conventional 3 or 5 fans. So how would you characterise this instrument especially in view of your use of reverse fan bracing? Why did you make the sandwiched back: what do you think this adds to the mix?

Jason Wolverton
03-13-2017, 09:38 PM
Thanks, guys...

I like cedar a lot. I'm not sure if the reverse fan bracing changes the sound a lot, but the geometry seemed to make sense on this uke as a l laid out the bracing; seems Pepe Romero has already been doing this so I'm a little late to the game. haha.

The arched brace-less back is something borrowed from the Australian school of classical guitar lutherie. I once owned a Jim Redgate guitar with an arched back and liked it. Instead of laying up several veneers like Greg Smallman and the like, I decided to make two outer skins that are thicker thus maintaining the integrity of the wood's sound. The carbon fiber core makes it very strong. I like the arched back because one can increase the cavity of the body without having wide sides; preserving immediacy of tone, but adding a bit of resonant air. Plus, it's just kind of fun to do and I think it looks cool.

greenscoe
03-14-2017, 12:29 AM
Thanks for your reply. I am aware of Pepe Romeros use of reverse fan bracing: it doesn't seem to be used by others so I was interested to hear whether you thought it had any significant effect on the instrument's sound.

I am also aware of Pepe's 'skin bracing'-essentially he reinforces the soundboard by gluing on a piece of timber (the skin) which is then graduated in thickness from the bridge area to the lining (so it results in a top of variable thickness). There are no braces apart from the above and below soundhole transverse braces. I am not aware of anyone else using this method of bracing but the attached sound sample seems to suggest it works fine.

https://www.youtube.com/watch?v=0zlXCdxWyj8

Jason Wolverton
03-25-2017, 07:29 AM
I wonder if he ever tried this on a classical guitar? I'm guessing there would be too much area to support and would result in some distortions or eventual failure. It would be an interesting experiment though...

Ukulele Eddie
03-25-2017, 01:26 PM
I admired this uke on your FB page. Really beautiful. Will you be posting a sound sample? Is it sold?

Jason Wolverton
03-25-2017, 05:35 PM
Thanks, Eddie. It's already sold, so no sound sample. There are higher resolution photos on my website for anyone interested...
http://jasonwolverton.com/index.php?/recenent-ukes/la-tarde-es-caramelo/

I'd be happy to build someone something similar.