PDA

View Full Version : First bowl back tenor uke



greenscoe
03-03-2015, 02:22 AM
Previously I raised the subject of the bowl back instrument.

( http://forum.ukuleleunderground.com/showthread.php?104534-Bowl-round-backed-ukulele )

The challenge of making a bowl back was too much for me to resist, so here is my first attempt.

It took me approx. 65 hours over a 15 day period to complete the instrument. It weighs 600gms (21 oz), about the same as my standard tenor uke. The soundboard is finished with acrylic lacquer, the remainder in Tru Oil.

It’s made in cherry with an Engelmann spruce soundboard. The back is made from 20 staves which were initially 3.5 mm thick. Rounding of the outside and inside surfaces reduces this to nearer 2-2.5mm: there are no back braces but the inside is reinforced with linen ribbon/paper pasted with PVA glue.

The soundboard has 3 long fan braces, the use of F holes allowing the maximum vibrating area. The neck is joined with a dovetail. Time will show whether these features are structurally satisfactory. The head design allows the instrument to be stable when set down on its back.

The stave profile and producing closely fitting staves are achieved using a jointer plane upside down in a vice (see Youtube). My lack of experience shows on the finished bowl. It is symmetrical, but the staves are not all equal. Most of the stave joints were not visible but I have used a rosewood dye on the cherry body to camouflage some dark glue lines. On future builds I would expect the staves to be equal and no glue lines to be visible. Darker woods or alternate light and dark staves minimises the visibility of poor joints.

I am happy with the instrument’s appearance: as a first build/learning exercise, I didn’t expect it to be perfect. Once a few basic techniques are learned, I don’t think a bowl back is beyond the capabilities of anyone who has the skills to make a standard uke from scratch.

The instrument sounds great (Living Waters high G). It’s loud, a little less sustain than usual, but is warm and rich. I expected it to be bright but it isn’t, in fact quite the opposite. It’s nothing like my only Engelmann topped tenor, more like my walnut/WR cedar tenor. It was easier to make than my archtop and acoustically is definitely more successful. I’m sure I’ll be making more bowl backs.

7681376814768167681776818

Kevs-the-name
03-03-2015, 02:32 AM
That is STUNNING

I am really impressed, would love to know how it 'feels' to play?
Does it sit nicely under your arm?

resoman
03-03-2015, 05:52 AM
Really nice! Great job

Vespa Bob
03-03-2015, 05:54 AM
You took the word right out of my head - STUNNING! I stand in awe at your dedication and skill.

Bob

Timbuck
03-03-2015, 05:57 AM
Well done ! :) your next one should have a contrasting stripy bowl. :cool:

rmeltzer
03-03-2015, 06:18 AM
Simply beautiful! A lutekelele.

PhilUSAFRet
03-03-2015, 06:42 AM
Lovely little thing. A stunner.

redyak3
03-03-2015, 07:22 AM
Beautiful job, skillful to say the least!

ksquine
03-03-2015, 07:35 AM
Wow...you did it. Looks great to me!! What ever defects you mentioned don't show up in the photos
I'm with Ken....make it stripey next time.

chenx2
03-03-2015, 09:37 AM
Looks a bit like a lute!

lauburu
03-03-2015, 10:47 AM
Excellent. Naples meets Waikiki. I'm with Ken. Make the next one striped. Bowl backed instruments with stripes have a long tradition going back to medieval times.
Miguel

Sven
03-03-2015, 12:10 PM
I'm really impressed! It looks great in this mono species way, and I disagree with the others - I never did like the striped ones. Too gaudy for a bitter viking.

greenscoe
03-03-2015, 10:29 PM
Thanks for all the praise! My purpose in posting was to show that making a bowl back isn't really as difficult as we all think and to encourage others to make one. There are clearly many makers on this forum much more skilled than me.

As was pointed out in the original post, it is difficult to hold: I never play standing but even sitting requires a different holding technique as it wants to slide off your lap. I made it to see if I could and to discover whether it would have its own sound. All who have heard or played the instrument think it sounds very different from a standard uke and is to their liking.

It's almost a year since I made my first uke, and I now have 11: 7 standard tenors, 1 soprano, 1 pineapple tenor, 1 archback and this bowlback. I have bought some viola Engelmann/maple to see if I can improve on my recent archtop and I certainly want to make more bowlbacks. I still do not consider that I have mastered the craft and have yet to offer an instrument for sale (congratulations Vespa Bob you got there before me!).

So what next? I am hoping to recoup some of my costs by selling some instruments in the near future, so I ought to focus my efforts on making a few 'perfect' standard instruments.

However, since I'm retired and I do this for fun, it doesn't work like that. I'll probably mouch around the house for a few days until I feel compelled to go into the workshop and start something: that's when I'll discover what comes next.

resoman
03-04-2015, 06:18 AM
I've played a few of the Ovation guitars with the round back and they are almost impossible to play sitting down without a strap. They keep trying to slide off your lap.

little timber
03-04-2015, 08:07 AM
how was it to do a binding job on this?

greenscoe
03-04-2015, 09:46 AM
little timber: ''how was it to do a binding job on this?''

I was expecting it to be difficult since the curvature of the sides varied-almost square at the heel and quite curved at the neck.

I proceeded carefully: first I used a flush cut router bit on a router table set with the bearing about 7 or 8 mm below the soundboard surface. This created a flat surface around the box square to the soundboard, cutting off nothing at the heel and most where there was most curvature. Next a bearing guided rebate bit was used to make an even 5 x 1 mm rebate around the box. This was followed with a 6 x 2 mm cut. In both cases the router bit bearing rode on the edge (2mm) of true surface I had created thereby ensuring a perfect binding rebate.

The purfling is just a strip of walnut veneer (0.6 mm) and the binding 1.6 mm maple. Its one of the best binding jobs I've done to date.

sequoia
03-04-2015, 10:06 AM
I proceeded carefully: .... This created a flat surface around the box square to the soundboard,

You proceeded carefully as well you should and you pulled it off. Nicely done sir. Nicely done.

granger
03-06-2015, 02:08 AM
Very nice!! challenging build to be sure. Glad it sounds as nice as it looks.

igorthebarbarian
03-06-2015, 07:03 PM
that is really really cool. very nicely done.

jcalkin
03-07-2015, 03:59 AM
It looks warm to the touch. Its so beautifully under-stated that it would feel good just to hold it now and then, even if it wasn't my favorite player.