Making A Boat Paddle Tenor Ukulele - Part 9 - Front and Back continued

Front and Back Skins

Previously, I have cut the four halves from a single piece of mango, and the bookmatched pairs were glued together to make two sets of skins - one for the front and one for the back of the ukulele.
The piece with the most figure will become the back - since the front will have a sound hole cut into it and a bridge glued onto its surface.  So it will lose some of its beauty.

The Back

The back needs cross bracing as well as a strengthening piece glued down the spine.
I start with the cross braces because the back has to have a radius, and it is easier to curve the back before applying the stiffening of the piece up and down the middle.
The cross braces are radiused on their edge to be glued to the back skin, and this gives the curve to the back of the uke.

 A normal hour-glass shaped uke has three cross braces, but this cutaway design has so much strengthening at its neck, that the third brace up there may well limit its acoustic qualities by making it too stiff.  So I am only using two braces this time.
I'll see how well it plays, and if it is a bad move I will correct it on my next uke.

Traditionally cross braces are made from quarter sawn spruce.
I don't have any, so I am using Huon Pine as a substitute.
I have made these slightly over-sized, and will plane them to shape once the glue is dry.

The edges are pared down to around 1/16inch where they meet the sides of the ukulele body.  I use a sharp paring chisel for this task.

Once the ends are pared, I lay down some masking tape to protect the skin from damage by the edge of the block plane, before planing the cross bracing  to a ridge across its top.  The tape is then removed.

Now I glue the strengthening strip along the spine of the back.  This is cross grained timber to add strength to this join in the bookmatched pair that make up the back skin.  I am using the same mango timber that makes up the body - only the grain now runs at right angles to the grain of the back.
The ridged cross braces can now be clearly seen.
This is left to dry while I work on the front soundboard.

The Soundboard

The front of the uke - the soundboard - needs special attention in a specific order.
A re-inforcing patch is glued on the back of the sound hole before it is cut out,

This adds strength to this fragile area.
Here they are laid out before gluing.
I cut the sound hole with the rosette cutter that I have made previously.

Cross braces are added above and below the sound hole for the same reason.

Once these are dry I then add the fan braces that will stiffen the body of the front skin and provide the stiffness needed to carry the bridge.

In my next post, I'll lay out the parts made thus far to give an overview of the assembly to come.
Happy shavings to all

Making A Boat Paddle Tenor Ukulele - Part 8 - Making and Fitting the Body Linings

The Hall Table is finished and gone to a good home.
Soooo - back to the Uke.

The body of the ukulele is complete as far as the sides go, but it needs a neck block.

I have made the neck block from Australian Cedar for its lightness, strength and tonal qualities.

The neck block is over large - as this end of the uke is a weak point on a cutaway design.
The neck block is glued in place.

I have been refining the body and getting things ready for the application of the linings.  These hold the top and bottom in place when they are glued to the body sides.
I made the linings on the tablesaw from a piece of paulonia.

The kerfed timber was then cut into strips on the bandsaw.

The full story of making the linings can be found here:
http://thevillagewoodworker.blogspot.com.au/2012/06/building-ukulele-part-1-timber.html
I had made enough when I constructed my first ukulele, to have sufficient for a few more ukes.
The linings are held in place by clamps and pegs until the glue is dry.

 

This is done one side at a time, to allow the mould to support the body, and for it to project enough to apply the clamps.

Once  the top is done, the mould is flipped over and the process repeated for the bottom.

Inevitably there is excess glue that needs cleaning up, as well as any bumps from the linings that project above the edges.
This is easily attended to with a small block plane.
Enough for today.
Next time I'll look at the front and the back.
Happy shavings to all.

Building a Hall Table - Part 3 - Sanding and Finishing

Although the timber is dressed and finished, it is quite open grained and in parts the grain reverses or becomes more like end grain.
It requires sanding through all grades of grit from 100 to 400 before a series finishing coats is applied.

I started with a three part mix of 1/3 boiled linseed oil, 1/3 polyurethane and 1/3 mineral turpentine.
This really brought out the colour in the camphor laurel.

It takes ages to dry at the moment because of the colder weather and the extra humidity.

After several coats, with a very light sanding with 400 grit between coats, I finished it with straight polyurethane.
Here are some images of the finished result:

Hooray - all done.
Now to get back to my ukulele ......................

Making A Boat Paddle Tenor Ukulele - Part 7 - Neck Preparations

Long time no uke .....
Where were we?
OK, the body shell sides are  ready and glued in place.
The neck block has to be made to accommodate the neck tenon.
I have chosen Australian cedar for this because of its lightness and strength.
The neck block has to be moulded to fit the shape of the top end of the body - it will also support both the top and back of the uke.

Cutting Out The Neck

I have made up the neck blank from three strips - two of sassafras and one of Australian rosewood.

 One end is cut to leave the middle piece of rosewood.  This will act as the tenon to anchor the neck and body together.

Here is the neck roughly laid out on the laminated blank.

The angle of the headstock to the neck is 15 degrees - easily measured with a protractor and angle gauge

After laying out the neck shape precisely, I cut it out on the bandsaw.

Here are the offcuts and the roughed out neck.  I keep the scraps - they will come in handy later.
All of the remaining shaping of the neck will be done by hand using rasps, spokeshaves and scrapers.

I'll move on to that next.
Happy shavings