Welcome to the second episode of the ukulele
bass build.
Let’s keep going!
If you haven’t seen the previous episode,
make sure you do so we are on the same page.
I’m scrapping some little glue squeeze outs
around the linings with my tiny chisels and
rounded over the corners of the end block.
Now I’m starting to work on the bracings.
On the first episode we cracked wood pieces
along the grain and sliced them parallel.
Now it’s time to plane and square them up.
I made a small jig to plane the wood to the
same thickness - in this case, 8 mm.
This will trap the boards in place and because
the left side is screwed, I can remove it
and adapt it to different width boards.
I used spruce and mahogany to make the bracings.
It’s recommended to use light weigh and
stable woods.
I sanded the mahogany top and run my hand
across the board to feel and mark any high
spots and hope everything was reasonably consistent
since I don’t have a drum sander or any
specific thickness measuring tools.
The final thickness was 2.5mm.
I wasn’t sure how I could make the rosette
completely by hand without taking up days
and lots of trial and error, so I invited
by buddy X-carve to help out with this part.
I carved a ring contour on a 1/8” inch piece
of padauk, which is the same wood I used for
the strip on the back of the ukulele.
I love using double sided tape as you can
clearly see along this entire build.
Now I can concentrate on making some super
thin strips out of maple to create two contrasting
rings.
I kept going back and forth between the workbench
and the bandsaw - cleaning and cutting, cleaning
and cutting.
Here I wanted to clean the rough sawn sides
of each strip but unfortunately I didn’t
get the best results.
What happened was that the thickness got thinner
where the double sided tape was, so that resulted
in some gaps between the rings.
It was a bit hard to press them in place.
I ended up adding some shims to press the
maple strips a little better towards the inside
of the ring.
I dropped a low viscosity CA glue everywhere.
To recess the matching ring on the ukulele
top, I set the zero point on the Easel Software
as my center point because I found it easier
to align with the center cross on the wood.
Now I can glue the inlay and cut the sound
hole.
I don’t recommend you getting your hand
so close to the bit like I do have here.
I as just afraid that the center piece would
pop out and fly or hit the bit and I knew
exactly where the spindle was going.
Back to the bracings, I cut some notches on
the horizontal bracings to fit the double
center ones and glue those in place.
Before jumping on the top and black glue ups,
I filled up some tiny gaps between the sides
and the linings with epoxy and lelf it to
cure.
At several points on the build, I did lightly
punch the pieces to hear how they sounded
like and I’ll bring the microphone closer
so you get a better idea.
Some of the steps might not make much sense
in terms of chronology because I started to
work on this part and then though and searched
about these other parts and made some progress
on those, then went back to the step I had
left behind.
And this was mostly due to not knowing exactly
what I was doing and always being afraid to
do something wrong and keep checking and rechecking
and rethinking some steps.
Shaping the bracings was quite challenging
as well as satisfying.
Since this is meant to be a bassy instrument,
I found out that by removing material in the
middle would make the instrument more deep
sound and resonant.
So this type of bracing is called scalloped
bracing.
For the sound board bracing, or the board
that will be on top, I am using a cross pattern
and I will glue the center of the cross fairly
close to the sound hole, which will also give
it a better response for low tone notes.
I shaped the bracing the same way, by removing
material in the middle portions and removing
material on the sides of the taller areas,
creating sort of triangular shapes.
The idea is to get the bracing as lightweight
as possible without compromising the strength.
To make the bridge plate, I laid some blue
tape to get the correct shape and angle so
I can easily transpose that to the piece of
mahogany.
The bridge plate is where the bridge is going
to be placed on the other side of the top
and drilled to allow for the strings to pop
though.
That area is going to have a lot of pressure,
so that’s why you need to reinforce it.
To give a nice detail on the let’s say,
the butt of the ukulele, I will inlay a trapezoidal
shape that will also give some continuity
to the back padauk strip.
So I clamped it in place and run a thin blade
saw keeping it against the side of the trapezium.
Then I cut two other random lines inside the
area to make it easier to chisel off.
Now that the sound board is done, I can start
thinking on gluing it to the side frame, but
before, there are some little recesses to
make so that the ends of the bracing have
a place to go and the top can sit flush agaisnt
the sides and linings.
I made a tops clamping jig that I found on
an amazing video from Greenfield guitars.
His jig is made out of clear rubber hose pipe
and the idea is just brilliant.
I ended up using some regular garden hose
pipe that I had around and it worked like
a charm.
You just need two clamps to apply even pressure
along the entire perimeter.
Oh I almost forgot I wanted to place a light
inside so that I could easily see any possible
gap.
After checking that no gap was visible, I
thoroughly inspected the seam and everything
looked fine.
After removing the mold, I gave it one coat
of shellac, which I didn’t really like in
the end.
The shellac cans I see on the american woodworkers’
shops could be a different recipe from this
one, but I really hated how it ended up sticky
for some days and left an uneven shine.
I can now repeat the process for the back
of the box.
in this case I had to make room for the end
and neck blocks.
I used the blue tape trick again to transpose
the correct shapes to the soundboard and remove
the remaining material.
this time I tried to use some alcohol to thin
the shellac a little bit but it became identical
with shinier areas than others.
Anyway, it is protected and I guess it is
what matters the most since you barely see
the interior faces.
I kept thinking about every step like 100
times a week and actually ordered all the
components needed before I really initiated
the build.
I am talking about the pickup and preamp,
the machine heads and fret wire.
Also kept studying the best time to include
those, and right before closing the box, I
noticed that the endpin jack was pretty small,
so I had to do some extra work.
I started to drill some holes on the side
but half way I thought this might not be the
best idea since I still had to apply pressure
to glue the back and was afraid that that
area might get fragile.
I went ahead and did the rest of the steps
instead.
I trimmed the top flush and worked on the
recess to fit the endpin jack that I previously
said that was too short.
Perfect.
On the first episode I mentioned that I shouldn’t
have made the neck block mortice all the way
through, so here I am fixing that.
I can finally close the box and hope for the
best.
Still fascinated with the garden hose clamp…
There is a looot of sanding to do now and
I’ll see you on the next episode where I’ll
be working on the neck.
Thank you so much for watching and for following
me during this fantastic and challenging journey.
Special thanks to Inventables and to all my
Patreon supporters who always have my back.
Stay tuned for next sunday’s video and go
get your hands dirty!
