Making "Ceol Binn Mór"

"Ceol Binn Mór"

 

I'm making "Ceol Binn Mór" an octave mandolin with a Lutz Spruce top and English Walnut back, sides and neck for Dave West.

 

Last updated 13/10/2018.

 

The main components are assembled.

Some "cunning plans".

Some initial glue ups to start with. The European Spruce top is initially thicknessed, jointed and glued up using hot hide glue and the tent method.

The English Walnut back is initially thicknessed, jointed and glued up using hot hide glue and the tent method.

The neck scarfe joint is cut and glued on the English Walnut neck blank using hot hide glue.

The stacked heel is glued up using hot hide glue.

The English Walnut sides are thicknessed. The soundport "porthole" is cut in the bass side using a 35mm Fostner bit.

Here's the result.

The Macassar Ebony centre of the "porthole" is cut and tested for fit.

The neck curves on the sides are bent by hand on the hot pipe and then the sides are bent in this jig. The sides are sprayed lightly with water, wrapped in brown paper and sandwiched as slat, side, slat, heating blanket, slat and the neck end clamped down to the bending form. The blanket is switched on and when hot enough the lower bout shape is bent.

After fine tuning on the hot pipe and some initial trimming here's the bent sides in the mould.

The Macassar Ebony porthole ring is glued to the Macassar Ebony backing plate using hot hide glue.

The centre of the porthole is then routed out.

Here's the result.

The Macassar "porthole" is then glued into the side using fish glue.

Next the Walnut neck block is made. This is a three piece construction and the first two pieces are glued together using hot hide glue.

The cap is glued on using fish glue.

The two 7mm bolt holes are then drilled.

The two 6mm holes are then drilled for the carbon fibre internal braces,

The slot for the fingerboard support is cut - the final depth of the slot will be determined when the neck is fitted.

The neck block is then initially shaped for the curvature of the sides.

The Lime tail block is made with two 6mm holes drilled for the internal carbon fibre braces. The 6mm carbon fibre tubes are then glued into the neck and tail blocks using. Next the neck-block is glued to the sides with fish glue using the mould as a jig.

The sides are glued to the tail block using fish glue.

The end graft channel is cut and the Macassar Ebony end graft flanked by black/ pear/ black purfling glued in using fish glue.

When the glue has dried the end graft is scraped flush - here's the result.

The sides are profiled to match the back's curvature and Claro Walnut reverse-kerfed linings glued on using fish glue.

The sides are profiled to match the top's curvature and Claro Walnut reverse-kerfed linings glued on using fish glue.

Then the English Walnut side braces are notched into the linings and glued in using hot hide glue.

Here's the completed rim set.

This instrument will have a K&K pickup fitted but due to the limited access through the small soundhole I have decided to glue the transducers onto the top before it is glued to the sides and so to check fit the 12mm hole for the end pin was drilled now.

Here's the K&K end-pin jack adjusted and test fitted - perfect.

The tailpiece will fit nicely above.

The Lutz spruce back X braces are profiled to a 10' radius and notched. The first X brace glued on in the go-bar deck using hot hide glue . . .

. . . followed by the second.

The lower bout ladder brace is profiled to a 10' radius glued on using hot hide glue.

The English Walnut X brace cap is glued on using hot-hide glue.

The braces are then carved and the back "voiced" - here's the result.

The English Walnut central rosette ring is cut from a back off-cut using the circle cutting jig . . .

. . . with this result.

Next the rosette channel is routed out of the top.

Here's the result.

The central English Walnut ring flanked by black/pear/black purfling is tested for fit and glued in using white pva glue.

The European Spruce soundhole patch is glued on using hot hide glue.

Then the soundhole is routed out . . .

. . . with this result.

The top is cut close to final shape.

Next the Lutz Spruce A Frame braces are glued on using hot hide glue, bass side first . . .

. . . followed by the treble side. These braces are flat and the ladder braces will be arched.

The Lutz Spruce brace below the soundhole is profiled to a 10' radius, notched to fit together with the A frame braces and then is glued on the top using hot-hide glue.

The main ladder brace is treated in the same fashion.

Finally the last ladder brace is glued on using hot-hide glue.

Lutz spruce caps are glued over the A frame braces.

Then the "voicing" process starts - the braces are profiled to give the top response I am looking for. When the top has been "voiced" to my satisfaction I sign and date it.

Here's the voiced top.

Notches are cut in the linings for the back brace ends and the back glued to the rim-set using fish glue.

The English Walnut back centre strips are glued in using hot hide glue.

As access through the soundhole will be tight I decided to glue the label in before the top went on.

The K&K transducers are glued onto the underside of the top using superglue gel.

Notches are cut in the linings to fit the top’s brace ends and the top is then glued to the rim-set using fish glue.