T005 Tenor Ukulele Pore Filling

Once the main construction work has been completed on each ukulele, the finishing process begins. The finishing schedule for each MAKAIO ukulele is a slow process that begins with initial sanding over the complete ukulele with 120 grit sandpaper. At this stage it is crucial to remove all scratches and scrapes from the timber surface, as they will not be able to be removed later in the finishing process. Following this, the ukulele is sanded all over with 180 grit then 220 grit sand papers.

Once the ukulele has been sanded to 220 grit, in most cases, the timber is required to be pore filled. Most hardwood timber species that are used for back, sides, and sometimes soundboards, have tiny pores in the grain. These pores can differ with the grain and growth direction of the timber. As the final finish on the ukuleles are only a very thin layer of oil varnish, these pores will show through as un-eveness in the finish appearance. To avoid this, the pores of the timber are initially filled with a clear flexible epoxy resin. For the T005 ukulele, two coats of epoxy were applied all over the ukulele.

T005 Tenor Ukulele

Epoxy Pore Fill Coating over Walnut Ukulele

Once the epoxy has cured on the ukulele, the entire instrument is again sanded with 220 grit sandpaper, removing all epoxy from the instrument surface, and leaving only that in the timber pores. This is followed by further sanding with 320 grit then 400 grit sandpaper, wiping the instrument over between each grade with a damp cloth to raise any loose grain fibre.

Once the ukulele has been finish sanded to 400 grit, the oil finishing process begins.

T005 Body Construction

A range of steps were completed to progress the ukulele from separate back, soundboard, sides and neck, to the completed or “boxed” body. At the start of this process, the components of the ukulele included the back and soundboard with shaped bracing, the neck with Spanish style heel block and carved heel, and the thicknessed timber for the sides. The steps that have been undertaken form the constructed body for this ukeulele include:

• Cutting the side pieces to the required profile, so that they follow the domed shape at the soundboard and backboard edges
• Bending the side pieces
• Joining the soundboard to the neck table at the heel block
• Shaping and joining the tail block to the soundboard
• Cutting the bent sides to length and joining to the soundboard
• Fixing the kerfed lining between the sides and the soundboard, and the sides and back
• Closing the ukulele body by joining the back plate
• Trimming the back and soundboard to be flush to the sides
  

Constructed Walnut Ukulele body - front

Constructed Walnut Ukulele body - back

Walnut Ukulele soundboard with Maple rosette

More details of this process have been written for the T004 ukulele, including images for most of these steps:

http://makaioukuleles.blogspot.com/2009/01/t004-body-construction.html

T005 Tenor UkuleleNeck Preparation

The neck for the T005 Tenor Ukulele will be made from Black Walnut to match the ukulele body. The neck blank from Hana Lima ‘Ia was already prepared to the correct thickness, and width, and came with pre-cut heel blocks. The first step in construction of the neck was to cut the scarf joint to form the neck/headstock connection. The scarf joint was cut and joined to produce a 12 degree break angle between the neck and headstock, which will provide the right string angle from the nut to the tuning slots, and ensure suitable downward string force over the nut. This break angle differs from the standard 15 degree angle used for ukuleles, as this ukulele will have a slotted “classical” style headstock. The top surface of the neck was slotted along its length, and a carbon fibre stiffening rod fitted to increase the stiffness and stability of the neck. The heel blocks were then glued to produce a stacked heel, following the plans for a Spanish style neck/body connection, with the neck joining to the body at the 12th fret.

Black Walnut neck blank

MAKAIO Ukuleles are constructed using a traditional Spanish style neck/body connection. With this neck design, the sides are fitted into pre-cut slots in the heel block, and the soundboard is recessed into the top of the heel block. This creates an extremely strong one-piece connection between the neck and body, which reduces loss of sound energy into the neck. By not using any mechanical fasteners to fix the neck to the body, the heel of MAKAIO Ukuleles is able to be made delicate and in proportion to the small body size, allowing access to more of the fretboard.

Once the neck scarf joint and heel blocks had been completed, the neck was tapered roughly oversize for the finished dimensions, and the heel carved to its final shape. The table of the heel blocks was then recessed to accept the soundboard so that when the body and neck are joined, the soundboard and upper neck surface are perfectly flush. The remainder of the heel blocks were cut down to reduce mass, while maintaining strength in the neck/body connection. The final step in preparation of the neck was to add ears to the side of the headstock, to provide increased width, and allow the headstock to later be cut to the unique MAKAIO slotted headstock shape.

Spanish style Black Walnut neck

T005 Tenor UkuleleSoundboard and Back

The Black Walnut back and soundboard sets from Hana Lima ‘Ia were already beautifully thickness sanded to approximately 3 mm when they arrived. These sets felt light and had a nice tap tone even at this thickness. The bookmatched plates were first edge sanded and centre joined at this thickness. Edge sanding is completed using sandpaper fixed onto a piece of 10 mm thick plate glass with an aluminium angle fence. Using sandpaper fixed onto glass ensures that the sanding surface is perfectly flat, and forms a straight and tight centre joint for the pairs of bookmatched plates. The pair of plates are then weighted and clamped tightly together during gluing with the use of small timber wedges. This technique for forming and gluing soundboard and back plate pairs produces very strong and tightly sealed joints that assist in transfer of energy within the plates with minimal loss.

Once the pair of bookmatched soundboard plates were centre joined, the rosette channel was then cut into the soundboard using a downcut spiral fluted router bit and a dremel tool with router base. In keeping with the simple appearance that this ukulele will have, the rosette has been designed using a combination of black/white purfling strips spaced with a thin solid maple timber strip. This rosette design will compliment the flamed maple bindings and the lighter streaks in the walnut soundboard. The black/white purlings and maple strip were inlaid to a depth of 0.9 mm and level sanded flush with the soundboard. The soundboard was then thickness sanded to 1.9 mm, at which point it felt suitably flexible cross-grain and had a sustained deep tap tone.

Black Walnut soundboard plate

.

Routed rosette channel

Black Walnut back, and soundboard

The soundboard of the T005 Tenor Ukulele has a traditional symmetric fan bracing that is made up of three longitudinal tone bars supporting the lower section of the soundboard. Two cross braces are also located above and below the soundhole. To provide additional strength and to reduce the chance of splitting along the soundboard grain, the area around the soundhole was reinforced with a 1.8 mm thick cross-grain spruce patch. Likewise, the soundboard area directly under the bridge was also reinforced with a cross-grain spruce patch.

The back plate of this ukulele has a ladder style cross brace system, with braces across the back plate at the upper bout, waist, and lower bout. The centre joint between each half of the back plates is reinforced between the cross braces with a cross-grain spruce graft to provide additional strength.

As with all MAKAIO Ukuleles, the spruce tone bars and braces that are used to provide structure to the ukulele are first shaped to a trapezoidal cross section. This allows the stiffness and bending strength of the braces to be maintained while significantly reducing their mass, due to the high moment of inertia for this cross sectional shape. Rectangular braces would be slightly more rigid, but would be significantly heavier than the trapezoidal section used. The base of the braces are then sanded to a domed profile with a 15 ft radius for back braces and 25 ft radius for soundboard braces. When glued to the soundboard and back using a domed dish workboard, the braces then force the plates to conform to the domed profile, which provides a pre-tensioning of the plates to help provide additional strength, allowing lighter soundboard and back plates to be used. The next step in preparing the soundboard and back for the ukulele is scalloping the ends of the braces to reduce the soundboard and back stiffness near to the ukulele perimeter, increasing their ability to resonate.

The final step at this stage of the construction process is the addition of the MAKAIO Ukuleles label to the inside of the back plate. This label has the MAKAIO logo, as well as information indicating the construction time, ukulele model, and ukulele production number.

Completed Black Walnut back and soundboard

Soundboard and back bracing

T005 Tenor UkuleleMaterials and Preparation

The T005 Tenor Ukulele will be made using Black Walnut for the body and neck, which was purchased from Hana Lima ‘Ia in Honolulu. The Black Walnut pieces have a mid brown colour, with darker purple hues and contrasting creamy streaks. I selected a pre-slotted Ebony fretboard, and a pre-cut Ebony bridge for use with this ukulele. The Ebony that Hana Lima ‘Ia provide is almost pure black, and gives instruments a clean and high class appearance.

Bookmatched Black Walnut back, and soundboard plates

.

End matched Black Walnut sides, and pre-slotted Ebony fretboard and bridge

.

Black Walnut neck blank

.

In keeping with the relatively simple aesthetics which will be achieved by having an all Walnut body, this ukulele will have a basic Black/White/Black rosette, and flamed Maple bindings which have a smooth cream colour. The bracing and patches for this ukulele will be high grade Engelmann Spruce, while the kerfed lining strips will be profiled Honduran Mahogany. The fretboard will be inlaid with mother of pearl marker dots.

The T005 Tenor Ukulele will have a slotted classical style headstock, with high quality Gotoh SEP700 open geared tuners. These are premium tuners and will maintain the aesthetic beauty of the instrument while ensuring stable tuning is maintained.

T005 Tenor UkuleleDesign Details

This ukulele was designed and started in early 2007, and I expect to be finished in late 2008. The ukulele will have a traditional fan braced soundboard with a ladder braced back. The soundboard will be built with a 25 ft radius domed profile, while the back will be built with a 15 ft domed profile. The neck will be designed as a standard length with a 12th fret body connection, and will be reinforced using a carbon fibre stiffening rod.

Components of the T005 Tenor Ukulele are:
Soundboard/Back/Sides: Black Walnut (Juglans nigra)
Neck: Black Walnut (Juglans nigra)
Fretboard: Ebony (Diospyros ebonum)
Bridge: Ebony (Diospyros ebonum)
Binding: Curly Maple (Acer saccharum)
Rosette: Black/White Strips
Tuners: Gotoh SEP700 Vintage Slot Head Open Geared Style in Nickel Plated