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View Full Version : Thicknesses for top & back plates before bracing and sides before bending?



woodpilenorwegian
10-09-2018, 03:07 AM
It's been 30 years or more since I've built a uke from scratch. I recently ordered a lovely flamed mahogany top, back, and side set from LMI. Since I don't have access to a thickness sander, I paid considerably extra for them to join and thickness both the top and back, and thickness the sides.

LMI thicknessed the top to approximately .115", the back to approximately .100", and the sides to approximately .095".

My questions:

1) How thick should the top and back plates be before they're braced?

2) How thick should the sides be before they are bent?

Any and all advice and/or suggestions would be sincerely appreciated.

Dusepo
10-09-2018, 04:57 AM
I do my soundboard and ribs at 2mm for ukuleles, thinner for some other instruments...

Timbuck
10-09-2018, 05:13 AM
Looks like you've got the top thicker than the back...I do all my mahogany sopranos .. Top = .0625" (1.6mm) ... Back = .070" (1,7mm) ... Sides = .070" up to .075" (1.9mm) ...So I recon you've got quite a bit of wood to remove.

sequoia
10-10-2018, 02:49 PM
LMI thicknessed the top to approximately .115", the back to approximately .100", and the sides to approximately .095".

My questions:

1) How thick should the top and back plates be before they're braced?

2) How thick should the sides be before they are bent?

Any and all advice and/or suggestions would be sincerely appreciated.

You will have to do some sanding down from those dimensions. It can be done with an orbital sander if you don't want to thin with a plane but it will take a little time though. My dimensions are for a tenor build. Also, I am not a pro luthier but a hobby builder but have lost track of how many I've built over the years.

1) top about ~80 (0.080") depending on tone but that is about where it seems to end up for me. Tap tone it or use deflection if you have those skills. If you are going to put in a rosette do it now at those present dimensions then sand down on the non-show side..... If you are going to radius the back (I do) then about 65.

2) I take my sides down to about 65-70 before bending. Depends on the wood. Thinner for safety on more problematic woods, a little thicker on easy bend woods. Mahogany bends politely in my experience with no problems but others have had problems so thin might be best.

Good luck! And send pictures!