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kkmm
02-09-2012, 06:54 AM
I plan to build a tenor ukulele from scratch.
Can someone tell me the proper thickness of the top and back boards ?
If the thickness depends on the choice of wood (such as mahogamy or spruce), please list them out as well.
Thanks

Rick Turner
02-09-2012, 07:14 AM
It depends on the stiffness of the wood. Ballpark...between 2 and 2.75 mm

ksquine
02-09-2012, 07:29 AM
Yep. I'd say 0.08" for hardwoods or 0.09 - 0.1" for soft woods is a good place to start. People spend lifetimes trying to find the "right" thickness for any piece of wood.

AlaskaTheo
02-09-2012, 08:12 AM
Is there any consideration of radius, when bringing fronts/backs to thickness? Also are there different approaches between flat builds and radiused ukes in terms of front/back thickness?

kkmm
02-10-2012, 10:39 AM
Thanks for the answers, the back board can certainly be 0.1" (2.5mm). I will try the same thickness for the top to start with.
Building instruments just caught my interest recently, I am about to finish a F-style mandolin this weekend.
I want to build a tenor ukulele for my own use.
It seems to me that ukulele is much easier to build as the top board is flat and the string tension is not as high as mandolin strings. And there is a wider choice of woods for ukulele.

Moore Bettah Ukuleles
02-10-2012, 10:55 AM
1.8 for the top with a 25 ' radius and three fan braces. 2.0 for the back with a 15' radius.

Pete Howlett
02-10-2012, 11:37 AM
I'm with Chuck and the reason is I want the back thicker to take the radius better. I have seen 'sinking' between the braces on the backs of instruments. After sanding the front is down to about 1.7mm but it does depend. I know some people here measure deflection and work off of that - see David Hurd's (beyond me) explanation of how this works. I just use my thmbs to check deflection at the bridge point to try and get an otimum delfection to stiffness ration.

kkmm
02-21-2012, 01:05 PM
Where can you buy wood for the top and the back, most preferrably in thin sheet form ?
I can certainly plane down the thickness a little but not by whole lot.

luvzmocha
02-21-2012, 01:19 PM
Where can you buy wood for the top and the back, most preferrably in thin sheet form ?
I can certainly plane down the thickness a little but not by whole lot.

I would check ebay. Search for "ukulele luthier." Most sellers offer sanding and joining.

dddd
02-21-2012, 03:48 PM
Get a micrometer from one of the big box stores.

Softwoods: Back .09 inches, soundboard .08 inches

Hardwood: Back .07 inches, soundboard .06 inches

Good luck

kkmm
02-21-2012, 04:05 PM
Thanks, I found a lot of them on eBay.

WOBster
02-21-2012, 04:32 PM
Do you sand to final thickness? Or is this something you have to "machine? Seems like planing to this thickness would be too risky...

Chris_H
02-21-2012, 05:27 PM
I just sold my planer, It has only been used 3 times in the last 4 years. My thickness sander is used very frequently, a 'backbone' in my shop that I would not want to do without. I find that if a board needs more than .125" removed, the bandsaw does that, any less, and the sander does the job. Actually the bandsaw will safely cut slices down to a little over 1/16". With the sander there is no danger of chatter or of high figure or expensive boards being 'exploded' by the planer.

Sanmatisse
02-22-2012, 08:10 AM
I find that if a board needs more than .125" removed, the bandsaw does that, any less, and the sander does the job.

+100% for all the reasons listed