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Ukulele top thickness
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Author:  Steve Brown [ Thu Dec 31, 2009 8:35 pm ]
Post subject:  Ukulele top thickness

I plan to make a few Ukuleles in 2010. What thickness would you use in Western Cedar, Adirondak and Koa sound board?
These will be Tenor Ukes.

Steve Brown

Author:  bluescreek [ Thu Dec 31, 2009 8:47 pm ]
Post subject:  Re: Ukulele top thickness

Steve .060 will be fine

Author:  unkabob [ Thu Dec 31, 2009 9:43 pm ]
Post subject:  Re: Ukulele top thickness

My experience with tenors ran mahogany at 70 thou. and spruce at 80 thou.

What bracing are you using?

Bob :ugeek:

Author:  Steve Brown [ Thu Dec 31, 2009 10:06 pm ]
Post subject:  Re: Ukulele top thickness

I plan to use a classical like fan bracing on the Western Red Cedar but would be open to suggestions on the Adi. I am finishing a Tiple with an Adi top and used X bracing on that. It has 10 steel strings so it is very different.

Steve Brown

Author:  HippetyHop [ Fri Jan 01, 2010 4:29 am ]
Post subject:  Re: Ukulele top thickness

Try leaving WRC a little thicker or you're in danger of sanding through it.

0.080" to be safe. At 0.060 it is very frail, and you could sand through it in a couple of swipes.

Cheers Hip.

Author:  bluescreek [ Fri Jan 01, 2010 7:42 am ]
Post subject:  Re: Ukulele top thickness

that is the how thin the uke makers are using in Hawaii . I just had a Martin SOP in that was at .060 with the finish.

Author:  David C. Hurd [ Fri Jan 01, 2010 10:07 am ]
Post subject:  Re: Ukulele top thickness

Hi Steve,

I'm an ukulele maker in Hawaii, now somewhat less active in building than before. I agree with Hip that the top should be thicker and in the 0.08" range. The following observations are the result of having built more than a 100 tenor size ukuleles.

How many strings will your tenor have? 4? 6? or 8? The more strings, the more tension and the greater the top thickness/bracing will have to be.

For 4-string tenors I would recommend 0.080" for koa, 0.085" for Western red cedar and depending on its stiffness relative to the koa, perhaps 0.075" for the Adirondack. I use a 0.030" thick graphite carbon bridge patch under my bridges for all my ukuleles. The patch extends 1/4" above and below the bridge and 1/2" beyond the ends. The ends of the bridge patch are rounded. I also use 5 fan braces and use deflection measurements to optimize the top. Much of the above and more about building guitar family instruments is discussed in greater detail on my website: http://www.ukuleles.com .

aloha,

Author:  bluescreek [ Fri Jan 01, 2010 12:13 pm ]
Post subject:  Re: Ukulele top thickness

Thanks for the education .

Author:  Steve Brown [ Fri Jan 01, 2010 3:53 pm ]
Post subject:  Re: Ukulele top thickness

Indeed - Thanks for the education. The web site was very informative!

Thanks again!

Steve Brown

Author:  Parser [ Fri Jan 01, 2010 9:40 pm ]
Post subject:  Re: Ukulele top thickness

I just closed the box on my prototype tenor uke. It has a fan brace pattern with 3 braces, one in the center and one on each side - all cross the cross-grain spruce bridge plate.

I'm a big believer in voicing steel string acoustics. As some folks have mentioned, I think you can really hear them start to move when doing things like sanding the top with a random orbital sander. Are ukes similar in this regard? I'm not sure how "open" the uke should sound in order to indicate proper voicing. Thanks in advance for any comments you might have...!

Best,
Trevor

Author:  David C. Hurd [ Fri Jan 01, 2010 11:19 pm ]
Post subject:  Re: Ukulele top thickness

Hi Trevor,

When I first switched from ukulele maker (hobbiest) to ukulele maker (trying to make a living), I noticed something on my tenor ukuleles. When I thought I had thinned the edges and top to the right amount using a random orbital sander, suddenly the body began to make a really loud resonant sound. It turned out that the RPM's of the sander and the resonant frequency of the air resonance had coincided at that point. So the sander was driving the air frequency to make this resonant sound. And I thought "Wow, I've really found something I can use and repeat and make great ukuleles!". Problem was, that although the ukuleles sounded great for a little while, the top was too thin and it eventually cratered. Undesirable... :(

So you need to be a little careful with respect to your voicing approach and building. Personally, I prefer more braces to less braces so three braces for a tenor would be too few for me. Further, I like to arch the top (free stiffness with no added mass) and maintain the arch all through the top-to-sides and back-to-sides gluing process with clamps and a form. Nothing new here just mentioning it because it's so important. I've seen so many ukuleles that have dished tops BEFORE the strings are even on the instrument. Bad juju...

In any case, since I'm a complete cluck when it comes to tap toning an instrument, I went to the top compliance approach which worked for me. 'Nuff said about that since I've mentioned it so many times...

aloha,

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