Making "Ceol Binn"

"Ceol Binn"

 

I'm making "Ceol Binn" a mandolin with a European Spruce top and English Walnut back, sides and neck for Malcolm Banks.

 

Last updated 24/6/2018.

 

tr>

The main components are assembled.

Some "cunning plans".

The English Walnut sides are thicknessed and a hole for the "porthole" soundport cut in the bass side using a 35mm Forstner bit.

Here's the result.

The Ovangkol 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 Ovangkol "porthole" ring is glued to an Ovangkol backing ring using hot hide glue.

The "porthole" is then cut out using a 25mm Forstner bit.

Here's the result.

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

The two pieces of the American Black Walnut neck block are glued together using hot hide glue.

The slot for the fingerboard support is then cut, the neck block shaped to the side contours and a thin English Walnut veneer strip stuck on the rear face. Then the two 5mm holes are drilled for the carbon fibre internal braces and finally the 7mm bolt hole is drilled.

The American Black Walnut tail block has two 5mm holes drilled for the carbon fibre rods.

The American Black Walnut tail block is then shaped to the side curvature and the Ovangkol end graft glued on using hot hide glue.

The sides are then glued to the neck-block with fish glue using this jig.

The two 5mm carbon fibre buttress braces are then attached using epoxy.

The sides are then glued to the tail block together with black/ white/ black purfling using fish glue.

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 English Walnut central rosette ring is cut using the circle cutting jig . . .

. . . with this result.

Then a rosette channel is cut in the top . . .

. . . with this result.

The English Walnut rosette ring and black/ white/ black inner and outer purflings are test fitted and glued in using white pva glue.

Here's the completed rosette with the top cut close to final shape.

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

Then the soundhole is routed out.

Here's the result.

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

. . . followed by the treble side.

The Lutz spruce main ladder brace is profiled to a 13' radius, notched to fit the A Frame braces and then is glued on the top using hot-hide glue.

Next the transverse brace is glued in after it has been notched to fit over the A Frame braces.

Finally the small brace behind the soundhole patch is glued on using hot-hide glue.

The back is marked for the position of the braces. The Lutz Spruce back X braces are profiled to a 10' radius and notched. The centre strip is notched and 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 sides are profiled to match the back's curvature and the American Black Walnut reverse-kerfed linings glued on using fish glue.

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

Then the American Black Walnut side braces are notched into the linings and glued in using hot hide glue. A block for the offset pickup jack is also glued in.

A 12mm hole is drilled for the jack and the pickup test fitted.

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.

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.

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.

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 supper glued onto the top.

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.

The Ovangkol bindings have b/w/b side purflings glued on, the neck curves bent by hand on the hot pipe and then the bent in this jig.

Here's the result.

The top binding channels are cut using the binding jig to the depth of the bindings plus side purflings. The channels are stopped just short of the end-graft. Purfling pieces are stuck using double-sided tape over the end-graft. The binding channel is then cut over the end graft with the jig riding on these so that the depth cut is just that of the binding. The end graft side purflings can then be mitred using a chisel.

The process is repeated on the back.

Next the top purfling channels are cut . . .

. . . followed by the back.

The top bindings and purflings are glued in using fish glue . . .

. . . followed by the back bindings and puflings.

Finally the side bindings and purflings next to the neck are fitted and glued in.

The bindings are then scraped and sanded flush and the top is cut for the floating fingerboard. Here's the finished box.

Next 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 truss rod slot is routed out.

Then the slots for the outer two carbon-fibre rods are routed.

The carbon fibre truss rod is glued in using fish glue. The outer carbon fibre rods with English Walnut caps are glued in with fish glue and clamped while the glue dries.

The Bog Oak headstock veneer is glued onto the top of the headstock using fish glue.

The Bog Oak veneer is bent to the shape of the volute and glued on the rear of the headstock using fish glue.