Making "Bogha Fada"

"Bogha Fada"

 

I'm making a "crossover" nylon string guitar, where possible with woods used in archery, called "Bogha Fada" - "Long Bow" in Gaelic. It is based on my parlour/Terz guitar body modified to be slightly longer and have an asymmetric body shape with soft cutaway in the style of my "Buachaill Mór" model. It has a 640mm scale length, slotted headstock and 12 frets clear of the body. It will have a Port Orford Cedar (used for making arrows) top that came from a tree that grew in my front garden, Yew (traditionally used in longbows) back and sides, Ash (used for Medieval longbows) neck, Holly (used to make Medieval low draw-weight practice bows for children) bindings and East Indian Rosewood (used for modern bow cores) headstock veneers, bridge and fingerboard.

 

Last updated 25/2/2020.

 

Here are the initial plans.

The Yew sides have been thicknessed. The bass side will have a "porthole" soundport so a 40mm hole is made with a Forstner bit.

An insert is put in the hole while the side is bent.

Then it's into the Fox-Bender with the heating blanket. The wood is given a very light spritzing of water, wrapped in brown paper and then put in the "sandwich" of slat, wood in paper, slat, blanket, slat When the temperature gets to 150°C the waist is cranked down about ¾ of the way down, the lower bout bent, then the upper bout and then the waist tightened fully down. I leave it hot for a couple of minutes to drive out the moisture then switch off and let it cool. I then give it another heat and cool cycle.

The cutaway on the treble side is bent by hand on the hot pipe. Here are the bent and trimmed sides in the mould.

The two sections of the Port Orford Cedar soundport "porthole" are glued together.

The centre of the porthole is cut out using a 32mm Forstner bit.

The porthole is then glued to the side using fish glue.

The Ash neck block is marked out, the curve to match the cutaway side made and has the bolt holes drilled.

The 6mm holes are then drilled for the carbon fibre flying-buttress rods.

The slot for the fingerboard extension support is cut and the fingerboard extension support glued in using hot hide glue.

The treble side is glued to the neck block.

A piece of Holly binding together with black/ white/ black purfling is inlet into the end of the cutaway side and a Holly binding strip glued onto the neckblock end on the cutaway side.

The Ash tail-block has the Holly end-graft glued on using hot hide glue.

The treble side together with a black / white/ black purfling is glued onto the tail-block using hot hide glue.

The bass side is glued to the neck block.

The bass side together with a black / white/ black purfling is glued onto the tail-block using hot hide glue.

Here's the rim set in the mould.

The back of the rim-set was profiled both for the back curvature and for the reduction in height from the tail-block to neck-block. Then the Port Orford Cedar back linings are glued in using fish glue.

The top of the rim-set was profiled for the top curvature and the Port Orford Cedar top linings glued in using fish glue.

Next the Port Orford Cedar side braces are notched into the linings and glued in with hot hide glue.

Then the carbon fibre rod flying-buttress braces are fitted.

Here's the completed rim-set.

The Yew back edges are prepared and checked for perfect fit and they are then taped and glued with hot-hide glue using the "tent method".

The slot for the backstrip is routed out using a 10mm router bit.

The Holly back strip and black/ white/ black purfling edgings are glued in.

The back is cut close to the final shape.

The bracing positions are marked. The first European Spruce X brace is then glued in using hot hide glue after notching and profiling the bottom surface to a 10' radius.

The second X brace is glued in.

Then the ladder braces are glued on in the go-bar deck using hot hide glue, first the lower bout . . .

. . . followed by the upper bout.

The Yew cap over the X braces is glued on using fish glue.

The braces are carved and the back "voiced".

The back linings are notched to accept the brace ends and the back is glued on using fish glue.

The Port Orford Cedar top is thicknessed and joined with hot hide glue using the "tent" method.

The soundhole is going to be "bound" with Yew. Firstly a Yew soundhole patch is cut to shape and glued on using hot hide glue and a caul.

Then a rosette channel is cut in the top down to the soundhole patch.

Here's the result.

The Yew rosette ring and black/ white/ black outer purfling are test fitted and glued in using white pva glue.

Next a step is routed in the inner edge of the rosette and then the soundhole is routed out. This gives the look of a totally bound soundhole and the fingerboard edge will finish at the beginning of the step to give a complete Yew ring around the inner edge of the soundhole.

Here's the result.

The top is cut close to the final shape.

Then the European Spruce A frame braces that are inlet into the neck block are glued on.

The European Spruce braces were prepared to just over 6mm wide. The top X braces were then profiled to a 13' radius, the notch cut in each brace and the first brace glued in the gobar deck using hot hide glue.

Followed by the second.

The upper transverse brace is notched to go over the A frame braces and is glued on.

The Yew bridge patch is glued on in the go-bar deck using hot hide glue and a caul.

The European Spruce X brace cap is then glued on.

Then the first tone-bar . . .

. . . then the second split tone bar is glued on.

Then the bass side finger braces . . .

. . . followed by the treble side.

The top is "voiced" and when I am happy I signed and dated it.

Here's the braced and "voiced" top.

The Yew centre strips are glued on the back using hot hide glue.

The notches for the brace ends are cut in the top linings and the top glued on using fish glue.

The black/white/black side purfling was glued onto the Holly bindings. They were then taped together and bent in the Fox-Bender.

Then it's out with "The Scutter" to cut the binding channels. The channels are first cut on the top the width of the linings and the depth of the linings plus side purflings. Some scrap pieces of the side purfling are stuck onto the top at the end graft with double-sided tape. The router rides on these to cut the rest of the binding channel. The channels are tidied up with a chisel and the side purflings can be mitred.

Then the back binding channels were cut using the same process.

Next the router is set to cut the back purfling channels and these are routed out.

The back purflings were then glued in using fish glue.

Next the router is set to cut the top purflings and these are routed out.

The top purflings are then glued in using fish glue.

The back bindings were then glued in using fish glue.

The top bindings were then glued in using fish glue.

Here's the box after the bindings have been scraped and sanded flush and the hole for the neck extension cut.

The neck will be five pieces of wood - two outer pieces of Ash around a black veneer/ holly/ black veneer core. Here's the Ash plank.

The two Ash pieces are cut to approximate shape.

The neck pieces are then glued together using fish glue.

The next job is to route the truss rod slot.

Next the slots for the two carbon fibre rods are routed.

The truss rod is then glued in with an Ash cap together with the carbon fibre rods.

The East Indian Rosewood headstock veneer has the nut edge sanded at an angle to match the headstock to neck-shaft angle and then it’s glued on together with veneers of black/ Holly/ black using fish glue.

The East Indian Rosewood veneer back-strap for the headstock was bent on the hot-pipe and glued on together with veneers of black/ Holly/ black using fish glue.

Next the peghead sides are shaped and the tuner holes drilled using this jig.

Next the slots for the tuners are routed using the jig and a spiral downcut router bit.

Here’s the result.

The holes are then rebated for the tuners to fit.

The peghead is then shaped. Here it is with the tuners test fitted.

The neck shaft is cut to shape and the fit tested. The neck heel is sanded to fit the body. The positions for the threaded inserts are marked, the holes drilled and the inserts fitted.

The neck is bolted on to the body and the alignment checked.