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.
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
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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
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