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Habanera Hal
02-04-2016, 11:47 AM
Hi all! I've had a lovely back and side set of Spalted Waterfall Bubinga for a Tenor build in my shop for years and decided it was time to do something with it. I have a few questions and would appreciate any answers, opinions, or suggestions. I haven't built a proper uke in about 3 years, so I'm a bit rusty.

1) Due to the spalting, there are numerous pin-sized worm holes. What's the best way to fill these, and should they be filled before or after bending the sides?

2) The sides are about .150" thick at this point. What should I thin them to before bending?

3) I was going to use curly redwood for the top, but just came into possesion of a nice, wide piece of straight grained Bubinga that could be used as a one-piece top without the need for joining. Would there be any advantage to using the bubinga over the redwood?

4) I want to try a laminated neck (my first). Considering birds-eye maple with a center core of bubinga with an ebony fretboard. I haven't decided yet whether to construct with a bolt-on or Spainish-style neck. Would this combo be too heavy for a tenor uke?

Again, any help in making these decisions is greatly appreciated. Thanks!

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Michael Smith
02-04-2016, 11:57 AM
[QUOTE=
1) Due to the spalting, there are numerous pin-sized worm holes. What's the best way to fill these, and should they be filled before or after bending the sides?

CA and dust mixed together

2) The sides are about .150" thick at this point. What should I thin them to before bending?

.070 to .080

3) I was going to use curly redwood for the top, but just came into possesion of a nice, wide piece of straight grained Bubinga that could be used as a one-piece top without the need for joining. Would there be any advantage to using the bubinga over the redwood?

The harder the wood the more difficult it is to make a good sounding uke. I would not try to make a ukulele top from wood harder that Koa or Walnut on my fist trip to the rodeo.

4) I want to try a laminated neck (my first). Considering birds-eye maple with a center core of bubinga with an ebony fretboard. I haven't decided yet whether to construct with a bolt-on or Spainish-style neck. Would this combo be too heavy for a tenor uke?

That depends on your likes and dislikes. For many it could be too heavy. On the other hand if you play with a strap it wouldn't matter.

Jim Hanks
02-04-2016, 01:43 PM
I'm not a luthier but do you have to fill the worm holes for structural reasons? If not, I'd say leave them unfilled as part of the "charm" of this build.

sequoia
02-04-2016, 04:47 PM
I've never made an uke from Bubinga (bababababinga), but is that gonna stop me from commenting. Ha ha ah... I think that is some pretty darn interesting looking wood. I'm a sucker for spalted wood. Gonna make a killer good looking uke.

1) You could do as Michael says about the wormholes or you could also just use an aliphatic wood glue (aka Titebond) and wood dust to fill the holes which might be a little more controllable and less anxious/messy. As to the question of fill before or after bending: good question and I don't really know. I think I would fill after bending which would eliminate any weirdness that might happen with hot glue and hot wood and plus no worries about sanding through the fill on sand out which would not be good.

2) Ditto ~ 0.075

3) Michael said: The harder the wood the more difficult it is to make a good sounding uke. I would not try to make a ukulele top from wood harder that Koa or Walnut on my fist trip to the rodeo. This so true and I couldn't agree more. Margin for error seems to be much less with harder woods. Bubinga has a Janka hardness of about 2,500 which is plenty darn plenty hard. However, if it was me I would use the babinga for the top since it is so pretty and damn the torpedoes and full speed ahead. As for redwood: I'm knee deep in the stuff here and I still can't decide if I like it not. Currently I'm trending to the not.

4) I never understood this neck weight issue/discussion so I won't comment. Whatever... However I vote for bolt-on and ditch the Spanish heel.

Good luck and send pictures!

Pete Howlett
02-05-2016, 02:59 AM
Use a softwood for the top. Use a 'kinder' and more stable wood like alder or tulipwood for a laminated neck...

Habanera Hal
02-05-2016, 03:35 AM
Thank you all for your input. From what you say, I'll probably go with the cedar top. The color is not that different from the bubinga, which I'll probably use for one of my CBG's. Curious as to the Alder/Tulipwood neck - will do some research on those. Decided on a bolt-on neck after a construction dream I had last night (really!) I'll start a construction thread with lots of pictures so everyone can either praise or ridicule my work. I'll take a long time, no rush on this one.

ksquine
02-05-2016, 06:06 AM
I'd just fill the holes with clear CA. They add character so no need to hide them
I thin sides to 0.075" for tenors. I haven't used spalted wood before but I hear it can be fragile. I'd thin the waist and upper bout areas to 0.065" for insurance while bending. You can always add braces after its bent.
Definitely pick the redwood for the top.
The laminated neck sounds good. It will be heavier than a mahogany neck but not much. It depends if you're one of those people who's crazy for body-heavy balance
I'd use a bolt on neck joint

Pete Howlett
02-05-2016, 08:00 AM
Alder and Tulipwood/poplar are really underrated as neck woods I guess because you can get the stuff at Home Depot! However I have used both but the European variety of alder which carves like soap, requires no grain filling and is a dream to work, often having a very subtle 'flame' in it. Respected Finnish guitar maker Juha Lottonen uses alder exclusively for neck wood on his guitars and for ukulele. You really don't need that south American brown stuff. You could even use Portland cedar - great stuff for neck material. The only time I had serious seam separation was on a weissenborn I made from bubinga - struggled to bend and work this wood even though I had successfully used it in my furniture making business. Not sure why you want to use exotic foreign hardwoods when you have such lovely wood in the US... if I was working there all my ukes would be made from either claro walnut or myrtle...